First trimester risk of preeclampsia and rate of spontaneous birth in patients without preeclampsia.

BACKGROUND: First-trimester screening for preeclampsia using a combination of maternal risk factors and mean arterial pressure, uterine artery pulsatility index, and placental growth factor, as proposed by the Fetal Medicine Foundation, provides effective prediction of preterm preeclampsia. Placental dysfunction is a potential precursor of spontaneous birth. OBJECTIVE: The objective of this study was to examine if the estimated risk of preeclampsia is associated with the gestational age at onset of spontaneous delivery in the absence of preeclampsia. STUDY DESIGN: This was a secondary analysis of the data from the Screening programme for pre-eclampsia trial in which there was a comparison of the performance of first-trimester screening for preterm preeclampsia using the Fetal Medicine Foundation model vs a traditional history-based risk scoring system. A subgroup of women from the trial with spontaneous onset of delivery (labor with intact membranes or preterm prelabor rupture of membranes) was included in this study and was arbitrarily divided into 3 groups according to the risk for preterm preeclampsia as determined by the Fetal Medicine Foundation model at 11 to 13 weeks' gestation as follows: group 1 low risk (˂1/100); group 2 intermediate risk (1/50 to 1/100); and group 3 high risk (˃1/50). A survival analysis was carried out using a Kaplan-Meier estimator and a Cox regression analysis with stratification by the 3 preeclampsia risk groups. Occurrence of spontaneous birth in the study groups was compared using log-rank tests and hazard ratios. RESULTS: The study population comprised 10,820 cases with delivery after spontaneous onset of labor among the 16,451 cases who participated in the Screening programme for pre-eclampsia trial. There were 9795 cases in group 1, 583 in group 2, and 442 in group 3. The gestational age at delivery was <28, <32, <35, <37, and <40 weeks in 0.29%, 0.64%, 1.68%, 4.52%, and 44.97% of cases, respectively, in group 1; 0.69%, 1.71%, 3.26%, 7.72%, and 55.23% of cases, respectively, in group 2; and 0.45%, 1.81%, 5.66%, 13.80%, and 63.12% of cases, respectively, in group 3. The curve profile of gestational age at spontaneous birth in the 3 study groups was significantly different overall and in pairwise comparisons (P values <.001). The Cox regression analysis showed that risks increased for spontaneous birth by 18% when the intermediate-risk group was compared with the low-risk group (P˂.001) and by 41% when the high-risk group was compared with the low-risk group (P˂.001). CONCLUSION: In this study that investigated birth after spontaneous onset of labor in women without preeclampsia, there were 2 major findings. First, the duration of pregnancy decreased with increasing first-trimester risk for preeclampsia. Second, in the high-risk group, when compared with the low-risk group, the risk for spontaneous birth was 4 times higher at a gestational age of 24 to 26 weeks, 3 times higher at 28 to 32 weeks, and 2 times higher at 34 to 39 weeks. These differences present major clinical implications for antepartum counselling, monitoring, and interventions in these pregnancies.

Maternal vascular indices at 36 weeks' gestation in the prediction of preeclampsia.

BACKGROUND: Epidemiological studies have shown that women with preeclampsia (PE) are at increased long term cardiovascular risk. This risk might be associated with accelerated vascular ageing process but data on vascular abnormalities in women with PE are scarce. OBJECTIVE: This study aimed to identify the most discriminatory maternal vascular index in the prediction of PE at 35 to 37 weeks' gestation and to examine the performance of screening for PE by combinations of maternal risk factors and biophysical and biochemical markers at 35 to 37 weeks' gestation. STUDY DESIGN: This was a prospective observational nonintervention study in women attending a routine hospital visit at 35 0/7 to 36 6/7 weeks' gestation. The visit included recording of maternal demographic characteristics and medical history, vascular indices, and hemodynamic parameters obtained by a noninvasive operator-independent device (pulse wave velocity, augmentation index, cardiac output, stroke volume, central systolic and diastolic blood pressures, total peripheral resistance, and fetal heart rate), mean arterial pressure, uterine artery pulsatility index, and serum concentration of placental growth factor and soluble fms-like tyrosine kinase-1. The performance of screening for delivery with PE at any time and at <3 weeks from assessment using a combination of maternal risk factors and various combinations of biomarkers was determined. RESULTS: The study population consisted of 6746 women with singleton pregnancies, including 176 women (2.6%) who subsequently developed PE. There were 3 main findings. First, in women who developed PE, compared with those who did not, there were higher central systolic and diastolic blood pressures, pulse wave velocity, peripheral vascular resistance, and augmentation index. Second, the most discriminatory indices were systolic and diastolic blood pressures and pulse wave velocity, with poor prediction from the other indices. However, the performance of screening by a combination of maternal risk factors plus mean arterial pressure was at least as high as that of a combination of maternal risk factors plus central systolic and diastolic blood pressures; consequently, in screening for PE, pulse wave velocity, mean arterial pressure, uterine artery pulsatility index, placental growth factor, and soluble fms-like tyrosine kinase-1 were used. Third, in screening for both PE within 3 weeks and PE at any time from assessment, the detection rate at a false-positive rate of 10% of a biophysical test consisting of maternal risk factors plus mean arterial pressure, uterine artery pulsatility index, and pulse wave velocity (PE within 3 weeks: 85.2%; 95% confidence interval, 75.6%-92.1%; PE at any time: 69.9%; 95% confidence interval, 62.5%-76.6%) was not significantly different from a biochemical test using the competing risks model to combine maternal risk factors with placental growth factor and soluble fms-like tyrosine kinase-1 (PE within 3 weeks: 80.2%; 95% confidence interval, 69.9%-88.3%; PE at any time: 64.2%; 95% confidence interval, 56.6%-71.3%), and they were both superior to screening by low placental growth factor concentration (PE within 3 weeks: 53.1%; 95% confidence interval, 41.7%-64.3%; PE at any time: 44.3; 95% confidence interval, 36.8%-52.0%) or high soluble fms-like tyrosine kinase-1-to-placental growth factor concentration ratio (PE within 3 weeks: 65.4%; 95% confidence interval, 54.0%-75.7%; PE at any time: 53.4%; 95% confidence interval, 45.8%-60.9%). CONCLUSION: First, increased maternal arterial stiffness preceded the clinical onset of PE. Second, maternal pulse wave velocity at 35 to 37 weeks' gestation in combination with mean arterial pressure and uterine artery pulsatility index provided effective prediction of subsequent development of preeclampsia.

First-trimester prediction of preterm pre-eclampsia and prophylaxis by aspirin: Effect on spontaneous and iatrogenic preterm birth.

OBJECTIVE: To report the predictive performance for preterm birth (PTB) of the Fetal Medicine Foundation (FMF) triple test and National Institute for health and Care Excellence (NICE) guidelines used to screen for pre-eclampsia and examine the impact of aspirin in the prevention of PTB. DESIGN: Secondary analysis of data from the SPREE study and the ASPRE trial. SETTING: Multicentre studies. POPULATION: In SPREE, women with singleton pregnancies had screening for preterm pre-eclampsia at 11-13 weeks of gestation by the FMF method and NICE guidelines. There were 16 451 pregnancies that resulted in delivery at ≥24 weeks of gestation and these data were used to derive the predictive performance for PTB of the two methods of screening. The results from the ASPRE trial were used to examine the effect of aspirin in the prevention of PTB in the population from SPREE. METHODS: Comparison of performance of FMF method and NICE guidelines for pre-eclampsia in the prediction of PTB and use of aspirin in prevention of PTB. MAIN OUTCOME MEASURE: Spontaneous PTB (sPTB), iatrogenic PTB for pre-eclampsia (iPTB-PE) and iatrogenic PTB for reasons other than pre-eclampsia (iPTB-noPE). RESULTS: Estimated incidence rates of sPTB, iPTB-PE and iPTB-noPE were 3.4%, 0.8% and 1.6%, respectively. The corresponding detection rates were 17%, 82% and 25% for the triple test and 12%, 39% and 19% for NICE guidelines, using the same overall screen positive rate of 10.2%. The estimated proportions prevented by aspirin were 14%, 65% and 0%, respectively. CONCLUSION: Prediction of sPTB and iPTB-noPE by the triple test was poor and poorer by the NICE guidelines. Neither sPTB nor iPTB-noPE was reduced substantially by aspirin.

Performance of machine-learning approach for prediction of pre-eclampsia in a middle-income country.

OBJECTIVE: Pre-eclampsia (PE) is a serious complication of pregnancy associated with maternal and fetal morbidity and mortality. As current prediction models have limitations and may not be applicable in resource-limited settings, we aimed to develop a machine-learning (ML) algorithm that offers a potential solution for developing accurate and efficient first-trimester prediction of PE. METHODS: We conducted a prospective cohort study in Mexico City, Mexico to develop a first-trimester prediction model for preterm PE (pPE) using ML. Maternal characteristics and locally derived multiples of the median (MoM) values for mean arterial pressure, uterine artery pulsatility index and serum placental growth factor were used for variable selection. The dataset was split into training, validation and test sets. An elastic-net method was employed for predictor selection, and model performance was evaluated using area under the receiver-operating-characteristics curve (AUC) and detection rates (DR) at 10% false-positive rates (FPR). RESULTS: The final analysis included 3050 pregnant women, of whom 124 (4.07%) developed PE. The ML model showed good performance, with AUCs of 0.897, 0.963 and 0.778 for pPE, early-onset PE (ePE) and any type of PE (all-PE), respectively. The DRs at 10% FPR were 76.5%, 88.2% and 50.1% for pPE, ePE and all-PE, respectively. CONCLUSIONS: Our ML model demonstrated high accuracy in predicting pPE and ePE using first-trimester maternal characteristics and locally derived MoM. The model may provide an efficient and accessible tool for early prediction of PE, facilitating timely intervention and improved maternal and fetal outcome. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Eficiencia de un enfoque de aprendizaje automático para la predicción de la preeclampsia en un país de ingresos medios OBJETIVO: La preeclampsia (PE) es una complicación grave del embarazo asociada a morbilidad y mortalidad materna y del feto. Dado que los modelos de predicción actuales tienen limitaciones y pueden no ser aplicables en situaciones con recursos limitados, se propuso desarrollar un algoritmo de aprendizaje automático (AA) que ofrezca una solución con potencial para desarrollar una predicción precisa y eficiente de la PE en el primer trimestre. MÉTODOS: Se realizó un estudio de cohorte prospectivo en Ciudad de México para desarrollar un modelo de predicción de la PE pretérmino (PEp) en el primer trimestre utilizando AA. Para la selección de variables se utilizaron las características maternas y los múltiplos de la mediana (MdM) obtenidos localmente para la presión arterial media, el índice de pulsatilidad de la arteria uterina y el factor de crecimiento placentario sérico. El conjunto de datos se dividió en subconjuntos de datos de entrenamiento, de validación y de test estadístico. Se empleó un método de red elástica para la selección de predictores, y el rendimiento del modelo se evaluó mediante el área bajo la curva de características operativas del receptor (ABC) y las tasas de detección (TD) con tasas de falsos positivos (TFP) del 10%. RESULTADOS: El análisis final incluyó a 3050 mujeres embarazadas, de las cuales 124 (4,07%) desarrollaron PE. El modelo de AA mostró una buena eficiencia, con un ABC de 0,897, 0,963 y 0,778 para la PEp, la PE de aparición temprana (PEat) y cualquier tipo de PE (todas las PE), respectivamente. Las TD con TFP del 10% fueron del 76,5%, 88,2% y 50,1% para la PEp, PEat y todas las PE, respectivamente. CONCLUSIONES: Nuestro modelo de AA demostró una alta precisión en la predicción de la PEp y la PEat utilizando características maternas del primer trimestre y MdM calculados localmente. El modelo puede proporcionar una herramienta eficiente y accesible para la predicción temprana de la PE, facilitando la intervención oportuna y la mejora de los resultados maternos y del feto.

Ophthalmic artery Doppler at 36 weeks' gestation in prediction of pre-eclampsia: validation and update of previous model.

OBJECTIVE: To validate and extend a model incorporating maternal ophthalmic artery Doppler at 35-37 weeks' gestation in the prediction of subsequent development of pre-eclampsia (PE). METHODS: This was a prospective validation study of screening for PE (defined according to the 2019 American College of Obstetricians and Gynecologists criteria) by maternal ophthalmic artery peak systolic velocity (PSV) ratio in 6746 singleton pregnancies undergoing routine care at 35 + 0 to 36 + 6 weeks' gestation (validation dataset). Additionally, the data from the validation dataset were combined with those of 2287 pregnancies that were previously used for development of the model (training dataset), and the combined data were used to update the original model parameters. The competing-risks model was used to estimate the individual patient-specific risk of delivery with PE at any time and within 3 weeks from assessment by a combination of maternal demographic characteristics and medical history with PSV ratio alone and in combination with the established PE biomarkers of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum soluble fms-like tyrosine kinase-1 (sFlt-1). We evaluated the predictive performance of the model by examining, first, the ability to discriminate between the PE and non-PE groups using the area under the receiver-operating-characteristics curve and the detection rate (DR) at fixed screen-positive (SPR) and false-positive rates of 10% and, second, calibration by measuring the calibration slope and calibration-in-the-large. McNemar's test was used to compare the performance of screening by a biophysical test (maternal factors, MAP, UtA-PI and PSV ratio) vs a biochemical test (maternal factors, PlGF and sFlt-1), low PlGF concentration (< 10th percentile) or high sFlt-1/PlGF concentration ratio (> 90th percentile). RESULTS: In the validation dataset, the performance of screening by maternal factors and PSV ratio for delivery with PE within 3 weeks and at any time after assessment was consistent with that in the training dataset, and there was good agreement between the predicted and observed incidence of PE. In the combined data from the training and validation datasets, good prediction for PE was achieved in screening by a combination of maternal factors, MAP, UtA-PI, PlGF, sFlt-1 and PSV ratio, with a DR, at a 10% SPR, of 85.0% (95% CI, 76.5-91.4%) for delivery with PE within 3 weeks and 65.7% (95% CI, 59.2-71.7%) for delivery with PE at any time after assessment. The performance of a biophysical test was superior to that of screening by low PlGF concentration or high sFlt-1/PlGF concentration ratio but not significantly different from the performance of a biochemical test combining maternal factors with PlGF and sFlt-1 for both PE within 3 weeks and PE at any time after assessment. CONCLUSION: Maternal ophthalmic artery PSV ratio at 35-37 weeks' gestation in combination with other biomarkers provides effective prediction of subsequent development of PE. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Validation of machine-learning model for first-trimester prediction of pre-eclampsia using cohort from PREVAL study.

OBJECTIVE: Effective first-trimester screening for pre-eclampsia (PE) can be achieved using a competing-risks model that combines risk factors from the maternal history with multiples of the median (MoM) values of biomarkers. A new model using artificial intelligence through machine-learning methods has been shown to achieve similar screening performance without the need for conversion of raw data of biomarkers into MoM. This study aimed to investigate whether this model can be used across populations without specific adaptations. METHODS: Previously, a machine-learning model derived with the use of a fully connected neural network for first-trimester prediction of early (< 34 weeks), preterm (< 37 weeks) and all PE was developed and tested in a cohort of pregnant women in the UK. The model was based on maternal risk factors and mean arterial blood pressure (MAP), uterine artery pulsatility index (UtA-PI), placental growth factor (PlGF) and pregnancy-associated plasma protein-A (PAPP-A). In this study, the model was applied to a dataset of 10 110 singleton pregnancies examined in Spain who participated in the first-trimester PE validation (PREVAL) study, in which first-trimester screening for PE was carried out using the Fetal Medicine Foundation (FMF) competing-risks model. The performance of screening was assessed by examining the area under the receiver-operating-characteristics curve (AUC) and detection rate (DR) at a 10% screen-positive rate (SPR). These indices were compared with those derived from the application of the FMF competing-risks model. The performance of screening was poor if no adjustment was made for the analyzer used to measure PlGF, which was different in the UK and Spain. Therefore, adjustment for the analyzer used was performed using simple linear regression. RESULTS: The DRs at 10% SPR for early, preterm and all PE with the machine-learning model were 84.4% (95% CI, 67.2-94.7%), 77.8% (95% CI, 66.4-86.7%) and 55.7% (95% CI, 49.0-62.2%), respectively, with the corresponding AUCs of 0.920 (95% CI, 0.864-0.975), 0.913 (95% CI, 0.882-0.944) and 0.846 (95% CI, 0.820-0.872). This performance was achieved with the use of three of the biomarkers (MAP, UtA-PI and PlGF); inclusion of PAPP-A did not provide significant improvement in DR. The machine-learning model had similar performance to that achieved by the FMF competing-risks model (DR at 10% SPR, 82.7% (95% CI, 69.6-95.8%) for early PE, 72.7% (95% CI, 62.9-82.6%) for preterm PE and 55.1% (95% CI, 48.8-61.4%) for all PE) without requiring specific adaptations to the population. CONCLUSIONS: A machine-learning model for first-trimester prediction of PE based on a neural network provides effective screening for PE that can be applied in different populations. However, before doing so, it is essential to make adjustments for the analyzer used for biochemical testing. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Screening for pre-eclampsia by maternal serum glycosylated fibronectin and angiogenic markers at 36 weeks' gestation.

OBJECTIVES: First, to examine the predictive performance of maternal serum glycosylated fibronectin (GlyFn) at 35 + 0 to 36 + 6 weeks' gestation in screening for delivery with pre-eclampsia (PE) and delivery with gestational hypertension (GH) at ≥ 37 weeks' gestation, both within 3 weeks and at any time after the examination. Second, to compare the predictive performance for delivery with PE and delivery with GH of various combinations of biomarkers, including GlyFn, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). Third, to compare the predictive performance for delivery with PE and delivery with GH by serum PlGF concentration, sFlt-1/PlGF concentration ratio and the competing-risks model with different combinations of biomarkers as above. Fourth, to compare the predictive performance of screening at 11 + 0 to 13 + 6 weeks vs 35 + 0 to 36 + 6 weeks for delivery with PE and delivery with GH at ≥ 37 weeks' gestation. METHODS: This was a case-control study in which maternal serum GlyFn was measured in stored samples from a non-intervention screening study in singleton pregnancies at 35 + 0 to 36 + 6 weeks' gestation using a point-of-care device. We used samples from women who delivered at ≥ 37 weeks' gestation, including 100 who developed PE, 100 who developed GH and 600 controls who did not develop PE or GH. In all cases, MAP, UtA-PI, PlGF and sFlt-1 were measured during the routine visit at 35 + 0 to 36 + 6 weeks. We used samples from patients that had been examined previously at 11 + 0 to 13 + 6 weeks' gestation. Levels of GlyFn were transformed to multiples of the expected median (MoM) values after adjusting for maternal demographic characteristics and elements from the medical history. Similarly, the measured values of MAP, UtA-PI, PlGF and sFlt-1 were converted to MoM. The competing-risks model was used to combine the prior distribution of the gestational age at delivery with PE, obtained from maternal risk factors, with various combinations of biomarker MoM values to derive the patient-specific risks of delivery with PE. The performance of screening of different strategies was estimated by examining the detection rate (DR) at a 10% fixed false-positive rate (FPR) and McNemar's test was used to compare the DRs between the different methods of screening. RESULTS: The DR, at 10% FPR, of screening by the triple test (maternal risk factors plus MAP, PlGF and sFlt-1) was 83.7% (95% CI, 70.3-92.7%) for delivery with PE within 3 weeks of screening and 80.0% (95% CI, 70.8-87.3%) for delivery with PE at any time after screening, and this performance was not improved by the addition of GlyFn. The performance of screening by a combination of maternal risk factors, MAP, PlGF and GlyFn was similar to that of the triple test, both for delivery with PE within 3 weeks and at any time after screening. The performance of screening by a combination of maternal risk factors, MAP, UtA-PI and GlyFn was similar to that of the triple test, and they were both superior to screening by low PlGF concentration (PE within 3 weeks: DR, 65.3% (95% CI, 50.4-78.3%); PE at any time: DR, 56.0% (95% CI, 45.7-65.9%)) or high sFlt-1/PlGF concentration ratio (PE within 3 weeks: DR, 73.5% (95% CI, 58.9-85.1%); PE at any time: DR, 63.0% (95% CI, 52.8-72.4%)). The predictive performance of screening at 35 + 0 to 36 + 6 weeks' gestation for delivery with PE and delivery with GH at ≥ 37 weeks' gestation was by far superior to screening at 11 + 0 to 13 + 6 weeks. CONCLUSION: GlyFn is a potentially useful biomarker in third-trimester screening for term PE and term GH, but the findings of this case-control study need to be validated by prospective screening studies. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Association between first-trimester uterine artery Doppler and crown-rump length with growth discordance: does it make a difference.

OBJECTIVES: The purpose of this study was to investigate the association between first-trimester uterine artery pulsatility index (UtA-PI) and crown-rump length discordance (CRLD) with growth discordance (GD) in twins and analyze the influence of chorionicity in these parameters. METHODS: This retrospective analysis integrated data from the twin pregnancy database of Centro Hospitalar São João (2019-2023), including 184 fetuses, with 19 monochorionic and 73 dichorionic gestations. To determine the association between UtA-PI and CRLD with GD, correlation analyses were computed and linear regression models were carried out. Separate analyses were conducted for each type of placentation. Logistic regression analysis was carried out to determine the association of mean UtA-PI and CRLD with severe GD, defined as discordance ≥25 %. RESULTS: GD≥25 % was detected in 9.80 % of pregnancies. A statistically significant difference between monochorionic and dichorionic gestations was found in crown-rump length (p=0.009), CRLD (p<0.001) and birth weight (p=0.025), but not in mean UtA-PI (p=0.853) or GD (p=0.556). Mean UtA-PI was significantly higher in discordant than in concordant pairs (p<0.001), but that association was not seen in CRLD (p=0.931). Mean UtA-PI and GD were correlated by the regression line "GD=3.844 × UtA-PI + 6.638", with R2 0.027. CRLD and GD were correlated by the regression line "GD=0.280 × CRLD + 10.79", with R2 0.010. Mean UtA-PI, but not CRLD, was significantly associated with severe GD (odds ratio, 22.753; p=0.002). CONCLUSIONS: Mean UtA-PI, but not CRLD, is associated with GD. The prevalence of severe GD increases significantly with increasing mean UtA-PI.

The role of second trimester uterine artery Doppler in predicting obstetric and neonatal outcomes in abnormal first trimester maternal serum pregnancy-associated plasma protein-A and free ß-human chorionic gonadotropin values.

AIM: This study aims to determine whether second-trimester uterine artery (UtA) Doppler combined with first-trimester abnormal pregnancy-associated plasma protein-A (PAPP-A) and ß-human chorionic gonadotropin (ß-Hcg) levels predicts adverse obstetric and neonatal outcomes. MATERIALS AND METHODS: This study of 289 pregnant women included 196 with normal PAPP-A and free ß-HCG values (control group) and 93 with abnormal values (study group) in the first-trimester screening test. Second-trimester UtA Doppler sonography was done in these pregnancies. The perinatal prediction and screening potential of UtA Doppler pulsatility index (PI) parameters were examined in the study group. RESULTS: UtA PI >95 percentile increased birth before the 37th week by 4.46 times, birth before the 34th week by 7.44 times, preeclampsia risk by 3.25 times, fetal growth restriction (FGR) risk by 4.89 times, and neonatal intensive care unit (NICU) admission rates by 3.66 times in the study group (p < 0.05 for all). UtA PI >95 percentile had 49.2% sensitivity and 82.1% specificity for birth before 37 weeks. For birth before 34 weeks, sensitivity was 80.0% and specificity 65.0%. FGR has 70.5% sensitivity and 67.1% specificity. Screening for preeclampsia has 66.6% sensitivity and 61.9% specificity. CONCLUSION: Adding UtA Doppler in the second trimester to pregnancies with abnormal PAPP-A and/or free ß-Hcg values in the first trimester may be a useful screening method for adverse outcomes.

Utility of the cerebro-placental-uterine ratio in predicting composite adverse perinatal outcomes in pregestational diabetes: A prospective cohort study.

PURPOSE: To examine the cerebro-placental-uterine ratio (CPUR) in pregnant women with pregestational diabetes and determine its role in predicting adverse prenatal outcomes. METHODS: This prospective, cohort study conducted at a tertiary hospital included 65 patients with pregestational diabetes (25 with type1 diabetes, 40 with type2 diabetes) and 130 low-risk patients in the control group. The cerebroplacental (CPR) ratio and the CPUR were calculated. Composite adverse perinatal outcome (CAPO) is defined as the presence of any of the following: (1) Neonatal intensive care unit (NICU) admission, (2) Apgar at 5 min <7, and (3) umbilical cord arterial pH <7.10. The relationship of CPR and CPUR with CAPO was investigated. RESULTS: CPR and CPUR were significantly lower in the pregestational diabetes group than in the control group. The NICU admission was higher in the case group. In receiver operating characteristic analyses, the optimal cut-off value of CPUR was 1.46 (AUC = 0.72, p = 0.003, 80% sensitivity, and 69% specificity) to predict CAPO and the optimal cut-off value of CPUR was 1.50 for NICU admission (AUC = 0.70, p = 0.013, 77% sensitivity, and 66% specificity). CONCLUSION: Low CPUR values were found to be associated with adverse perinatal outcomes in women with pregestational diabetes. With the increasing number of studies, CPUR is expected to be utilized more widely in routine obstetric practice.

Is mid-gestational uterine artery Doppler still useful in a setting with routine first-trimester pre-eclampsia screening? A cohort study.

OBJECTIVE: To evaluate whether routine mid-gestational uterine artery Doppler (UtAD) modifies the risk for preterm pre-eclampsia after first-trimester combined pre-eclampsia screening. DESIGN: Retrospective cohort study. SETTING: London Tertiary Hospital. POPULATION: A cohort of 7793 women with singleton pregnancies, first-trimester pre-eclampsia screening using the Fetal Medicine Foundation (FMF) algorithm and UtAD pulsatility index (PI) assessment at the mid-gestation ultrasound. METHODS: Pregnancies were divided into four groups: high risk in both trimesters (H1 H2 ), high risk in the first but not in the second trimester (H1 L2 ), low risk in the first but high risk in the second trimester (L1 H2 ) and low risk in both trimesters (L1 L2 ). MAIN OUTCOME MEASURES: Small for gestational age (SGA), hypertensive disorders of pregnancy (HDP) and stillbirth. RESULTS: In this cohort, 600 (7.7%) and 620 (7.9%) women were designated as being at high risk in the first and second trimesters, respectively. Preterm pre-eclampsia was more prevalent in the H1 L2 group (4.5%) than in women considered at low risk in the first trimester (0.4%, p < 0.0001). The prevalence of preterm pre-eclampsia in the L1 H2 group (3.3%) was significantly lower than that in women considered at high risk in the first trimester (7.0%, p = 0.0076), and was higher than that observed in the L1 L2 group (0.2%, p < 0.0001). The prevalence of SGA and term HDP followed similar trends. CONCLUSIONS: Pre-eclampsia risk after first-trimester FMF pre-eclampsia screening may be stratified through mid-gestational routine UtAD assessment. Pregnancy care should not be de-escalated for low mid-gestational UtAD resistance in women classified as being at high risk in the first trimester. The escalation of care may be justified in women at low risk but with high mid-gestational UtAD resistance.

Arterial stiffness for the early prediction of pre-eclampsia compared with blood pressure, uterine artery Doppler and angiogenic biomarkers: a prospective cohort study.

OBJECTIVE: Our aim was to evaluate the ability of arterial stiffness parameters to predict pre-eclampsia early compared with peripheral blood pressure, uterine artery Doppler and established angiogenic biomarkers. DESIGN: Prospective cohort study. SETTING: Tertiary care antenatal clinics in Montreal, Canada. POPULATION: Women with singleton high-risk pregnancies. METHODS: In the first trimester, arterial stiffness was measured by applanation tonometry, along with peripheral blood pressure and serum/plasma angiogenic biomarkers; uterine artery Doppler was measured in the second trimester. The predictive ability of different metrics was assessed through multivariate logistic regression. MAIN OUTCOME MEASURES: Arterial stiffness (carotid-femoral pulse wave velocity, carotid-radial pulse wave velocity) and wave reflection (augmentation index, reflected wave start time), peripheral blood pressure, ultrasound indices of velocimetry and circulating angiogenic biomarker concentrations. RESULTS: In this prospective study, among 191 high-risk pregnant women, 14 (7.3%) developed pre-eclampsia. A first-trimester 1 m/s increase in carotid-femoral pulse wave velocity was associated with 64% increased odds (P < 0.05), and a 1-millisecond increase in time to wave reflection with 11% decreased odds for pre-eclampsia (P < 0.01). The area under the curve of arterial stiffness, blood pressure, ultrasound indices and angiogenic biomarkers was 0.83 (95% confidence interval [CI] 0.74-0.92), 0.71 (95% CI 0.57-0.86), 0.58 (95% CI 0.39-0.77), and 0.64 (95% CI 0.44-0.83), respectively. With a 5% false-positive rate, blood pressure had a sensitivity of 14% for pre-eclampsia and arterial stiffness a sensitivity of 36%. CONCLUSIONS: Arterial stiffness predicted pre-eclampsia earlier and with greater ability than blood pressure, ultrasound indices or angiogenic biomarkers.

Screening for pre-eclampsia by maternal serum glycosylated fibronectin at 11-13 weeks' gestation.

OBJECTIVE: To examine the performance of screening for preterm and term pre-eclampsia (PE) at 11-13 weeks' gestation by maternal factors and combinations of maternal serum glycosylated fibronectin (GlyFn), mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF). METHODS: This was a case-control study in which maternal serum GlyFn was measured using a point-of-care device in stored samples from a non-intervention screening study of singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation. In the same samples, PlGF was measured by time-resolved fluorometry. We used samples from women who delivered with PE at < 37 weeks' gestation (n = 100), PE at ≥ 37 weeks (n = 100), gestational hypertension (GH) at < 37 weeks (n = 100), GH at ≥ 37 weeks (n = 100) and 1000 normotensive controls with no pregnancy complications. In all cases, MAP and UtA-PI had been measured during the routine 11-13-week visit. Levels of GlyFn were transformed to multiples of the expected median (MoM) values after adjusting for maternal demographic characteristics and elements of medical history. Similarly, the measured values of MAP, UtA-PI and PlGF were converted to MoMs. The competing-risks model was used to combine the prior distribution of gestational age at delivery with PE, obtained from maternal characteristics, with various combinations of biomarker MoM values to derive the patient-specific risks of delivery with PE or GH at < 37 and ≥ 37 weeks' gestation. Screening performance was estimated by examining the area under the receiver-operating-characteristics curve (AUC) and detection rate (DR) at 10% fixed false-positive rate (FPR). RESULTS: The maternal characteristics and elements of medical history with a significant effect on the measurement of GlyFn were maternal age, weight, height, race, smoking status and history of PE. In pregnancies that developed PE, GlyFn MoM was increased and the deviation from normal decreased with increasing gestational age at delivery. The DR and AUC of screening for delivery with PE at < 37 weeks' gestation by maternal factors alone were 50% and 0.834, respectively, and these increased to 80% and 0.949, respectively, when maternal risk factors were combined with MAP, UtA-PI and PlGF (triple test). The performance of the triple test was similar to that of screening by a combination of maternal factors, MAP, UtA-PI and GlyFn (DR, 79%; AUC, 0.946) and that of screening by a combination of maternal factors, MAP, PlGF and GlyFn (DR, 81%; AUC, 0.932). The performance of screening for delivery with PE at ≥ 37 weeks' gestation was poor; the DR for screening by maternal factors alone was 35% and increased to only 39% with use of the triple test. Similar results were obtained when GlyFn replaced PlGF or UtA-PI in the triple test. The DR of screening for GH with delivery at < 37 and ≥ 37 weeks' gestation by maternal factors alone was 34% and 25%, respectively, and increased to 54% and 31%, respectively, with use of the triple test. Similar results were obtained when GlyFn replaced PlGF or UtA-PI in the triple test. CONCLUSIONS: GlyFn is a potentially useful biomarker in first-trimester screening for preterm PE, but the findings of this case-control study need to be validated by prospective screening studies. The performance of screening for term PE or GH at 11 + 0 to 13 + 6 weeks' gestation by any combination of biomarkers is poor. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

ASPRE trial: effects of aspirin on mean arterial blood pressure and uterine artery pulsatility index trajectories in pregnancy.

OBJECTIVES: The mechanism by which aspirin prevents pre-eclampsia is poorly understood, and its effects on biomarkers throughout pregnancy are unknown. We aimed to investigate the effects of aspirin on mean arterial pressure (MAP) and mean uterine artery pulsatility index (UtA-PI) using repeated measures from women at increased risk of preterm pre-eclampsia. METHODS: This was a longitudinal secondary analysis of the Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-Based Pre-eclampsia Prevention (ASPRE) trial using repeated measures of MAP and UtA-PI. In the trial, 1620 women at increased risk of preterm pre-eclampsia were identified using the Fetal Medicine Foundation algorithm at 11 + 0 to 13 + 6 weeks, of whom 798 were randomly assigned to receive 150 mg/day aspirin and 822 were assigned to receive placebo daily from 11-14 weeks to 36 weeks of gestation or delivery, whichever came first. MAP and UtA-PI were measured at baseline and follow-up visits at 19-24, 32-34 and 36 weeks of gestation. Generalized additive mixed models with treatment by gestational age interaction terms were used to investigate the effects of aspirin on MAP and UtA-PI trajectories over time. RESULTS: Among 798 participants in the aspirin group and 822 in the placebo group, there were 5951 MAP and 5942 UtA-PI measurements. Trajectories of raw and multiples of the median (MoM) values of MAP did not differ significantly between the two groups (MAP MoM analysis: P-value for treatment by gestational age interaction, 0.340). In contrast, trajectories of raw and MoM values of UtA-PI showed a significantly steeper decline in the aspirin group than in the placebo group, with the difference mainly driven by a more pronounced reduction before 20 weeks of gestation (UtA-PI MoM analysis: P-value for treatment by gestational age interaction, 0.006). CONCLUSIONS: In women at increased risk of preterm pre-eclampsia, 150 mg/day aspirin initiated in the first trimester does not affect MAP but is associated with a significant decrease in mean UtA-PI, particularly before 20 weeks of gestation. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Glycosylated fibronectin improves first-trimester prediction of pre-eclampsia.

OBJECTIVE: To determine whether maternal serum glycosylated fibronectin (GlyFn) level in the first trimester increases the sensitivity of the Fetal Medicine Foundation (FMF) triple test, which incorporates mean arterial pressure, uterine artery pulsatility index and placental growth factor, when screening for pre-eclampsia (PE) in an Asian population. METHODS: This was a nested case-control study of Chinese women with a singleton pregnancy who were screened for PE at 11-13 weeks' gestation as part of a non-intervention study between December 2016 and June 2018. GlyFn levels were measured retrospectively in archived serum from 1685 pregnancies, including 101 with PE, using an enzyme-linked immunosorbent assay (ELISA), and from 448 pregnancies, including 101 with PE, using a point-of-care (POC) device. Concordance between ELISA and POC tests was assessed using Lin's correlation coefficient and Passing-Bablok and Bland-Altman analyses. GlyFn was transformed into multiples of the median (MoM) to adjust for maternal and pregnancy characteristics. GlyFn MoM was compared between PE and non-PE pregnancies, and the association between GlyFn MoM and gestational age at delivery with PE was assessed. Risk for developing PE was estimated using the FMF competing-risks model. Screening performance for preterm and any-onset PE using different biomarker combinations was quantified by area under the receiver-operating-characteristics curve (AUC) and detection rate (DR) at a 10% fixed false-positive rate (FPR). Differences in AUC between biomarker combinations were compared using the DeLong test. RESULTS: The concordance correlation coefficient between ELISA and POC measurements was 0.86 (95% CI, 0.83-0.88). Passing-Bablok analysis indicated proportional bias (slope, 1.08 (95% CI, 1.04-1.14)), with POC GlyFn being significantly higher compared with ELISA GlyFn. ELISA GlyFn in non-PE pregnancies was independent of gestational age at screening (P = 0.11), but significantly dependent on maternal age (P < 0.003), weight (P < 0.0002), height (P = 0.001), parity (P < 0.02) and smoking status (P = 0.002). Compared with non-PE pregnancies, median GlyFn MoM using ELISA and POC testing was elevated significantly in those with preterm PE (1.23 vs 1.00; P < 0.0001 and 1.18 vs 1.00; P < 0.0001, respectively) and those with term PE (1.26 vs 1.00; P < 0.0001 and 1.22 vs 1.00; P < 0.0001, respectively). GlyFn MoM was not correlated with gestational age at delivery with PE (P = 0.989). Adding GlyFn to the FMF triple test for preterm PE increased significantly the AUC from 0.859 to 0.896 (P = 0.012) and increased the DR at 10% FPR from 64.9% (95% CI, 48.7-81.1%) to 82.9% (95% CI, 66.4-93.4%). The corresponding DRs at 10% FPR for any-onset PE were 52.5% (95% CI, 42.3-62.5%) and 65.4% (95% CI, 55.2-74.5%), respectively. CONCLUSIONS: Adding GlyFn to the FMF triple test increased the screening sensitivity for both preterm and any-onset PE in an Asian population. Prospective non-intervention studies are needed to confirm these initial findings. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Association between transabdominal uterine artery Doppler and small-for-gestational-age: a systematic review and meta-analysis.

BACKGROUND: The association between uterine artery Doppler (UtA) measurements and small for gestational age (SGA) has not been quantitatively analyzed throughout the whole pregnancy. This systematic review and meta-analysis aims to comprehensively explore the association between UtA measurements and SGA in the first, second, and third trimesters. METHODS: Studies were searched from Pubmed, Embase, Cochrane Library, and Web of Science. Weighted mean difference (WMD), odds ratio (OR), and relative risk (RR) with 95% confidence interval (CI) were used as the effect size. Heterogeneity of all effect sizes was tested and quantified using I2 statistics. Sensitivity analysis was conducted for all outcomes, and publication bias was evaluated using Begg's test. RESULTS: A total of 41 studies were finally included in our meta-analysis. In the first trimester, mean PI was significantly higher in the SGA group than the non-SGA group (WMD: 0.31, 95%CI: 0.19-0.44). In the second trimester, odds of notch presence (OR: 2.54, 95%CI: 2.10-3.08), mean PI (WMD: 0.21, 95%CI: 0.12-0.30), and mean RI (WMD: 0.05, 95%CI: 0.05-0.06) were higher in the SGA group. Also, abnormal UtA measurements were associated with the increased odds of SGA (all P < 0.05). In the third trimester, PI z-score (WMD: 0.62, 95%CI: 0.33-0.91) and PI MoM (WMD: 0.08, 95%CI: 0.06-0.09) showed a significant increase in the SGA group. The odds of SGA were higher in the women with mean PI > 95% (OR: 6.03, 95%CI: 3.24-11.24). CONCLUSIONS: Abnormal UtA measurements were associated with high odds of SGA, suggesting that UtA might be an adjunctive screening method for SGA in the whole pregnancy.

Prediction of pre-eclampsia at St. Mary's hospital lacor, a low-resource setting in northern Uganda, a prospective cohort study.

BACKGROUND: Pre-eclampsia is the second leading cause of maternal death in Uganda. However, mothers report to the hospitals late due to health care challenges. Therefore, we developed and validated the prediction models for prenatal screening for pre-eclampsia. METHODS: This was a prospective cohort study at St. Mary's hospital lacor in Gulu city. We included 1,004 pregnant mothers screened at 16-24 weeks (using maternal history, physical examination, uterine artery Doppler indices, and blood tests), followed up, and delivered. We built models in RStudio. Because the incidence of pre-eclampsia was low (4.3%), we generated synthetic balanced data using the ROSE (Random Over and under Sampling Examples) package in RStudio by over-sampling pre-eclampsia and under-sampling non-preeclampsia. As a result, we got 383 (48.8%) and 399 (51.2%) for pre-eclampsia and non-preeclampsia, respectively. Finally, we evaluated the actual model performance against the ROSE-derived synthetic dataset using K-fold cross-validation in RStudio. RESULTS: Maternal history of pre-eclampsia (adjusted odds ratio (aOR) = 32.75, 95% confidence intervals (CI) 6.59-182.05, p = 0.000), serum alkaline phosphatase(ALP) < 98 IU/L (aOR = 7.14, 95% CI 1.76-24.45, p = 0.003), diastolic hypertension ≥ 90 mmHg (aOR = 4.90, 95% CI 1.15-18.01, p = 0.022), bilateral end diastolic notch (aOR = 4.54, 95% CI 1.65-12.20, p = 0.003) and body mass index of ≥ 26.56 kg/m2 (aOR = 3.86, 95% CI 1.25-14.15, p = 0.027) were independent risk factors for pre-eclampsia. Maternal age ≥ 35 years (aOR = 3.88, 95% CI 0.94-15.44, p = 0.056), nulliparity (aOR = 4.25, 95% CI 1.08-20.18, p = 0.051) and white blood cell count ≥ 11,000 (aOR = 8.43, 95% CI 0.92-70.62, p = 0.050) may be risk factors for pre-eclampsia, and lymphocyte count of 800 - 4000 cells/microliter (aOR = 0.29, 95% CI 0.08-1.22, p = 0.074) may be protective against pre-eclampsia. A combination of all the above variables predicted pre-eclampsia with 77.0% accuracy, 80.4% sensitivity, 73.6% specificity, and 84.9% area under the curve (AUC). CONCLUSION: The predictors of pre-eclampsia were maternal age ≥ 35 years, nulliparity, maternal history of pre-eclampsia, body mass index, diastolic pressure, white blood cell count, lymphocyte count, serum ALP and end-diastolic notch of the uterine arteries. This prediction model can predict pre-eclampsia in prenatal clinics with 77% accuracy.

The predictive value of uterine artery Doppler in the success rate of pregnancy from the first frozen embryo transfer during the implantation window.

BACKGROUND: Worldwide, frozen embryo transfer (FET) has become a new strategy for the treatment of infertility. The success of FET is closely related to endometrial receptivity. Does uterine artery Doppler during the implantation window predict pregnancy outcome from the first FET? METHODS: A total of 115 retrospectively collected cycles were included in the study, with 64 cycles of clinical pregnancy and 51 cycles of nonclinical pregnancy; There were 99 nonabsent end-diastolic flow (NAEDF) cycles and 16 absent end-diastolic flow (AEDF) cycles. The differences in uterine artery Doppler findings between different pregnancy outcomes were investigated. The clinical pregnancy rate and spontaneous abortion rate in the NAEDF and AEDF groups were compared. The predictive value of uterine artery Doppler during the implantation window in the success rate of pregnancy from the first FET was also investigated. RESULTS: Between the clinical pregnancy group and the nonclinical pregnancy group, there were no significant differences in the mean resistance index (mRI) (Z = -1.065, p = 0.287), mean pulsatility index (mPI) (Z = -0.340, p = 0.734), and mean peak systolic/end-diastolic velocity(mS/D) (Z = -0.953, p = 0.341); there were significant differences in the mean peak systolic velocity (mPSV) (Z = -1.982, p = 0.048) and mean end-diastolic velocity (mEDV) (Z = -2.767, p = 0.006). Between the NAEDF and AEDF groups, there was no significant difference in the clinical pregnancy rate (χ2 = 0.003, p = 0.959), and there was a significant difference in the spontaneous abortion rate (χ2 = 3.465, p = 0.019). Compared with uterine artery Doppler alone, its combination with artificial abortion history, waist-to-hip ratio, LH (Luteinizing hormone) of P (Progesterone) administration day, mPSV and mEDV had a higher predictive value regarding clinical pregnancy from the first FET [ROC-AUC 0.782, 95% CI (0.680-0.883) vs. 0.692, 95% CI (0.587-0.797)]. CONCLUSIONS: Uterine artery Doppler, particularly mPSV and mEDV during the implantation window, was useful for predicting clinical pregnancy, and AEDF was related to spontaneous abortion in the first trimester. Uterine artery Doppler combined with artificial abortion history, waist-to-hip ratio, LH of P administration day, mPSV and mEDV have a higher predictive value than uterine artery Doppler alone regarding the pregnancy from the first FET.

Role of the cerebro-placental-uterine ratio in predicting adverse perinatal outcome in low-risk pregnancies at term.

PURPOSE: The cerebroplacental ratio (CPR) is associated with adverse perinatal outcome (APO) in low-risk pregnancies near term. A Doppler parameter, which also includes information from the uterine vessels could potentially improve detection of subclinical placental dysfunction. The aim of this study is to investigate the performance of cerebro-placental-uterine ratio (CPUR) related to APO prediction in low-risk term pregnancies in > 40 + 0 weeks. METHODS: This is a retrospective cohort study. All low-risk pregnancies in which feto-maternal Doppler was examined from 40 + 0 weeks and an appropriate for gestational age fetus was present were included. ROC (receiver operating characteristic curves) analyses were performed to assess the predictive value of CPUR. The presence of at least one of the following outcome parameters was defined as composite APO (CAPO): operative delivery (OD) due to intrapartum fetal compromise (IFC), admission to the neonatal intensive care unit, umbilical cord arterial pH ≤ 7.15, 5 min APGAR ≤ 7. RESULTS: A total of n = 114 cases were included. Mean gestational age at examination and delivery were 40 + 3 weeks and 40 + 6 weeks, respectively. Overall, CAPO occurred in 38 of 114 cases (33.3%). ROC analyses showed a significant association of CPUR (AUC = 0.67, p = 0.004) and CPR (AUC = 0.68, p = 0.002) with CAPO. Additionally, CPUR (AUC = 0.64, p = 0.040) showed a predictive value for OD due to IFC. CONCLUSION: The CPUR in > 40 + 0 weeks showed a predictive value for CAPO and OD due to IFC in low-risk pregnancies. However, the extent to which CPUR can be used to optimize delivery management warrants further investigations in prospective interventional studies.

Diagnostic utility of serial circulating placental growth factor levels and uterine artery Doppler waveforms in diagnosing underlying placental diseases in pregnancies at high risk of placental dysfunction.

BACKGROUND: Placental pathology assessment following delivery in pregnancies complicated by preeclampsia, fetal growth restriction, abruption, and stillbirth reveals a range of underlying diseases. The most common pathology is maternal vascular malperfusion, characterized by high-resistance uterine artery Doppler waveforms and abnormal expression of circulating maternal angiogenic growth factors. Rare placental diseases (massive perivillous fibrinoid deposition and chronic histiocytic intervillositis) are reported to have high recurrence risks, but their associations with uterine artery Doppler waveforms and angiogenic growth factors are presently ill-defined. OBJECTIVE: To characterize the patterns of serial placental growth factor measurements and uterine artery Doppler waveform assessments in pregnancies that develop specific types of placental pathology to gain insight into their relationships with the timing of disease onset and pregnancy outcomes. STUDY DESIGN: A retrospective cohort study conducted between January 2017 and November 2021 included all singleton pregnancies with at least 1 measurement of maternal circulating placental growth factor between 16 and 36 weeks' gestation, delivery at our institution, and placental pathology analysis demonstrating diagnostic features of maternal vascular malperfusion, fetal vascular malperfusion, villitis of unknown etiology, chronic histiocytic intervillositis, or massive perivillous fibrinoid deposition. Profiles of circulating placental growth factor as gestational age advanced were compared between these placental pathologies. Maternal and perinatal outcomes were recorded. RESULTS: A total of 337 pregnancies from 329 individuals met our inclusion criteria. These comprised placental pathology diagnoses of maternal vascular malperfusion (n=109), fetal vascular malperfusion (n=87), villitis of unknown etiology (n=96), chronic histiocytic intervillositis (n=16), and massive perivillous fibrinoid deposition (n=29). Among patients who developed maternal vascular malperfusion, placental growth factor levels gradually declined as pregnancy progressed (placental growth factor <10th percentile at 16-20 weeks' gestation in 42.9%; 20-24 weeks in 61.9%; 24-28 weeks in 77%; and 28-32 weeks in 81.4%) accompanied by mean uterine artery Doppler pulsatility index >95th percentile in 71.6% cases. Patients who developed either fetal vascular malperfusion or villitis of unknown etiology mostly exhibited normal circulating placental growth factor values in association with normal uterine artery Doppler waveforms (mean [standard deviation] pulsatility index values: fetal vascular malperfusion, 1.14 [0.49]; villitis of unknown etiology, 1.13 [0.45]). Patients who developed either chronic histiocytic intervillositis or massive perivillous fibrinoid deposition exhibited persistently low placental growth factor levels from the early second trimester (placental growth factor <10th centile at 16-20 weeks' gestation in 80% and 77.8%, respectively; 20-24 weeks in 88.9% and 63.6%; 24-28 weeks in 85.7% and 75%), all in combination with normal uterine artery Doppler waveforms (mean pulsatility index >95th centile: chronic histiocytic intervillositis, 25%; massive perivillous fibrinoid deposition, 37.9%). Preeclampsia developed in 83 of 337 (24.6%) patients and was most common in those developing maternal vascular malperfusion (54/109, 49.5%) followed by chronic histiocytic intervillositis (7/16, 43.8%). There were 29 stillbirths in the cohort (maternal vascular malperfusion, n=10 [9.2%]; fetal vascular malperfusion, n=5 [5.7%]; villitis of unknown etiology, n=1 [1.0%]; chronic histiocytic intervillositis, n=7 [43.8%]; massive perivillous fibrinoid deposition, n=6 [20.7%]). Most patients experiencing stillbirth exhibited normal uterine artery Doppler waveforms (21/29, 72.4%) and had nonmaternal vascular malperfusion pathologies (19/29, 65.5%). By contrast, 28 of 29 (96.5%) patients experiencing stillbirth had ≥1 low placental growth factor values before fetal death. CONCLUSION: Serial circulating maternal placental growth factor tests, in combination with uterine artery Doppler waveform assessments in the second trimester, may indicate the likely underlying type of placental pathology mediating severe adverse perinatal events. This approach has the potential to test disease-specific therapeutic strategies to improve clinical outcomes. Serial placental growth factor testing, compared with uterine artery Doppler studies, identifies a greater proportion of patients destined to have a poor perinatal outcome because diseases other than maternal vascular malperfusion are characterized by normal uteroplacental circulation.