The role of cell-free DNA biomarkers and patient data in the early prediction of preeclampsia: an artificial intelligence model.

BACKGROUND: Accurate individualized assessment of preeclampsia risk enables the identification of patients most likely to benefit from initiation of low-dose aspirin at 12 to 16 weeks of gestation when there is evidence for its effectiveness, and enables the guidance of appropriate pregnancy care pathways and surveillance. OBJECTIVE: The primary objective of this study was to evaluate the performance of artificial neural network models for the prediction of preterm preeclampsia (<37 weeks' gestation) using patient characteristics available at the first antenatal visit and data from prenatal cell-free DNA screening. Secondary outcomes were prediction of early-onset preeclampsia (<34 weeks' gestation) and term preeclampsia (≥37 weeks' gestation). METHODS: This secondary analysis of a prospective, multicenter, observational prenatal cell-free DNA screening study (SMART) included singleton pregnancies with known pregnancy outcomes. Thirteen patient characteristics that are routinely collected at the first prenatal visit and 2 characteristics of cell-free DNA (total cell-free DNA and fetal fraction) were used to develop predictive models for early-onset (<34 weeks), preterm (<37 weeks), and term (≥37 weeks) preeclampsia. For the models, the "reference" classifier was a shallow logistic regression model. We also explored several feedforward (nonlinear) neural network architectures with ≥1 hidden layers, and compared their performance with the logistic regression model. We selected a simple neural network model built with 1 hidden layer and made up of 15 units. RESULTS: Of the 17,520 participants included in the final analysis, 72 (0.4%) developed early-onset, 251 (1.4%) preterm, and 420 (2.4%) term preeclampsia. Median gestational age at cell-free DNA measurement was 12.6 weeks, and 2155 (12.3%) had their cell-free DNA measurement at ≥16 weeks' gestation. Preeclampsia was associated with higher total cell-free DNA (median, 362.3 vs 339.0 copies/mL cell-free DNA; P<.001) and lower fetal fraction (median, 7.5% vs 9.4%; P<.001). The expected, cross-validated area under the curve scores for early-onset, preterm, and term preeclampsia were 0.782, 0.801, and 0.712, respectively, for the logistic regression model, and 0.797, 0.800, and 0.713, respectively, for the neural network model. At a screen-positive rate of 15%, sensitivity for preterm preeclampsia was 58.4% (95% confidence interval, 0.569-0.599) for the logistic regression model and 59.3% (95% confidence interval, 0.578-0.608) for the neural network model. The contribution of both total cell-free DNA and fetal fraction to the prediction of term and preterm preeclampsia was negligible. For early-onset preeclampsia, removal of the total cell-free DNA and fetal fraction features from the neural network model was associated with a 6.9% decrease in sensitivity at a 15% screen-positive rate, from 54.9% (95% confidence interval, 52.9-56.9) to 48.0% (95% confidence interval, 45.0-51.0). CONCLUSION: Routinely available patient characteristics and cell-free DNA markers can be used to predict preeclampsia with performance comparable to that of other patient characteristic models for the prediction of preterm preeclampsia. Logistic regression and neural network models showed similar performance.

Prediction of Cerebral Palsy or Death among Preterm Infants Who Survive the Neonatal Period.

OBJECTIVE: To assess whether neonatal morbidities evident by the time of hospital discharge are associated with subsequent cerebral palsy (CP) or death. STUDY DESIGN: This is a secondary analysis of data from a multicenter placebo-controlled trial of magnesium sulfate for the prevention of CP. The association between prespecified intermediate neonatal outcomes (n = 11) and demographic and clinical factors (n = 10) evident by the time of discharge among surviving infants (n = 1889) and the primary outcome of death or moderate/severe CP at age 2 (n = 73) was estimated, and a prediction model was created. RESULTS: Gestational age in weeks at delivery (odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.67-0.83), grade III or IV intraventricular hemorrhage (IVH) (OR: 5.3, CI: 2.1-13.1), periventricular leukomalacia (PVL) (OR: 46.4, CI: 20.6-104.6), and male gender (OR: 2.5, CI: 1.4-4.5) were associated with death or moderate/severe CP by age 2. Outcomes not significantly associated with the primary outcome included respiratory distress syndrome, bronchopulmonary dysplasia, seizure, necrotizing enterocolitis, neonatal hypotension, 5-minute Apgar score, sepsis, and retinopathy of prematurity. Using all patients, the receiver operating characteristic curve for the final prediction model had an area under the curve of 0.84 (CI: 0.78-0.89). Using these data, the risk of death or developing CP by age 2 can be calculated for individual surviving infants. CONCLUSION: IVH and PVL were the only neonatal complications evident at discharge that contributed to an individual infant's risk of the long-term outcomes of death or CP by age 2. A model that includes these morbidities, gestational age at delivery, and gender is predictive of subsequent neurologic sequelae. KEY POINTS: · Factors known at hospital discharge are identified which are independently associated with death or CP by age 2.. · A model was created and validated using these findings to counsel parents.. · The risk of death or CP can be calculated at the time of hospital discharge..

Fetal Tachycardia in the Setting of Maternal Intrapartum Fever and Perinatal Morbidity.

OBJECTIVE: The fetal consequences of intrapartum fetal tachycardia with maternal fever or clinical chorioamnionitis are not well studied. We evaluated the association between perinatal morbidity and fetal tachycardia in the setting of intrapartum fever. STUDY DESIGN: Secondary analysis of a multicenter randomized control trial that enrolled 5,341 healthy laboring nulliparous women ≥36 weeks' gestation. Women with intrapartum fever ≥ 38.0°C (including those meeting criteria for clinical chorioamnionitis) after randomization were included in this analysis. Isolated fetal tachycardia was defined as fetal heart rate (FHR) ≥160 beats per minute for at least 10 minutes in the absence of other FHR abnormalities. FHR abnormalities other than tachycardia were excluded from the analysis. The primary outcome was a perinatal composite (5-minute Apgar's score ≤3, intubation, chest compressions, or mortality). Secondary outcomes included low arterial cord pH (pH < 7.20), base deficit ≥12, and cesarean delivery. RESULTS: A total of 986 (18.5%) of women in the trial developed intrapartum fever, and 728 (13.7%) met criteria to be analyzed; of these, 728 women 336 (46.2%) had maternal-fetal medicine (MFM) reviewer-defined fetal tachycardia, and 349 of the 550 (63.5%) women during the final hour of labor had validated software (PeriCALM) defined fetal tachycardia. After adjusting for confounders, isolated fetal tachycardia was not associated with a significant difference in the composite perinatal outcome (adjusted odds ratio [aOR] = 3.15 [0.82-12.03]) compared with absence of tachycardia. Fetal tachycardia was associated with higher odds of arterial cord pH <7.2, aOR = 1.48 (1.01-2.17) and of infants with a base deficit ≥ 12, aOR = 2.42 (1.02-5.77), but no significant difference in the odds of cesarean delivery, aOR = 1.33 (0.97-1.82). CONCLUSION: Fetal tachycardia in the setting of intrapartum fever or chorioamnionitis is associated with significantly increased fetal acidemia defined as a pH <7.2 and base excess ≥12 but not with a composite perinatal morbidity. KEY POINTS: · The perinatal outcomes associated with fetal tachycardia in the setting of maternal fever are undefined.. · Fetal tachycardia was not significantly associated with perinatal morbidity although the sample size was limited.. · Fetal tachycardia was associated with an arterial cord pH <7.2 and base deficit of 12 or greater..

The RECIPE study: reducing emergency Caesareans and improving the Primiparous experience: a blinded, prospective, observational study.

BACKGROUND: The RECIPE study aims to validate a risk prediction model for intrapartum caesarean delivery which has been developed by our group. The Genesis study was a prospective observational study carried out by the Perinatal Ireland Research Consortium across 7 clinical centres in Ireland between October 2012 and June 2015. Genesis investigated a range of maternal and fetal parameters in a prospective blinded study of 2336 singleton pregnancies between 39 + 0-41 + 0 weeks' gestational age. This resulted in the development of a risk prediction model for Caesarean Delivery in nulliparous women at term. The RECIPE study now proposes to provide external validation of this risk prediction tool. METHODS: In order to externally validate the model, we aim to include a centre which was not involved in the original study. We propose a trial of risk-assignment for intrapartum caesarean amongst nulliparous women with a singleton pregnancy between 38 + 0 and 40 + 6 weeks' gestational age who are planning a vaginal birth. Results of the risk prediction tool will be concealed from participants and from midwives and doctors providing labour care.. Participants will be invited for an ultrasound scan and delivery details will be collated postnatally. The principal aim of this study is to externally validate the risk prediction model. This prediction model holds the potential to accurately identify nulliparous women who are likely to achieve an uncomplicated vaginal birth and those at high prospect of requiring an unplanned caesarean delivery. DISCUSSION: Validation of the Genesis prediction model would enable more accurate counselling for women in the antenatal setting regarding their own likelihood of requiring an intrapartum Caesarean section. It would also provide valuable personalised information to women about the anticipated course of their own labour. We believe that this is an issue of national relevance that will impact positively on obstetric practice, and will positively empower women to make considered, personalised choices surrounding labour and delivery.

Sex-Specific Genetic Susceptibility to Adverse Neurodevelopmental Outcome in Offspring of Pregnancies at Risk of Early Preterm Delivery.

OBJECTIVE: To evaluate sex-specific genetic susceptibility to adverse neurodevelopmental outcome (ANO, defined as cerebral palsy [CP], mental, or psychomotor delay) at risk for early preterm birth (EPTB, < 32 weeks). STUDY DESIGN: Secondary case-control analysis of a trial of magnesium sulfate (MgSO4) before anticipated EPTB for CP prevention. Cases are infants who died by the age of 1 year or developed ANO. Controls, matched by maternal race and infant sex, were neurodevelopmentally normal survivors. Neonatal DNA was evaluated for 80 polymorphisms in inflammation, coagulation, vasoregulation, excitotoxicity, and oxidative stress pathways using Taqman assays. The primary outcome for this analysis was sex-specific ANO susceptibility. Conditional logistic regression estimated each polymorphism's odds ratio (OR) by sex stratum, adjusting for gestational age, maternal education, and MgSO4-corticosteroid exposures. Holm-Bonferroni corrections, adjusting for multiple comparisons (p < 7.3 × 10-4), accounted for linkage disequilibrium between markers. RESULTS: Analysis included 211 cases (134 males; 77 females) and 213 controls (130 males; 83 females). An interleukin-6 (IL6) polymorphism (rs2069840) was associated with ANO in females (OR: 2.6, 95% confidence interval [CI]: 1.5-4.7; p = 0.001), but not in males (OR: 0.8, 95% CI: 0.5-1.2; p = 0.33). The sex-specific effect difference was significant (p = 7.0 × 10-4) and was unaffected by MgSO4 exposure. No other gene-sex associations were significant. CONCLUSION: An IL6 gene locus may confer susceptibility to ANO in females, but not males, after EPTB.

Use of the Robson Ten Group Classification System to categorise operative vaginal delivery.

BACKGROUND: Operative vaginal delivery (OVD), either vacuum or forceps, can be used to expedite vaginal delivery. While rates of OVD have been reducing worldwide, rates in Ireland remain high. The Robson Ten Group Classification System (TGCS) was originally created to compare rates of caesarean delivery between healthcare units, although no similar system exists for the analysis of OVD. AIMS: We sought to examine rates of OVD using the TGCS in an effort to understand which patient groups make significant contributions to the overall rate of OVD. MATERIALS AND METHODS: This is a retrospective cohort study of all women delivering in a tertiary-level university institution in Dublin, Ireland, from 2007 to 2016. Mode of delivery for all patients was extracted from contemporaneously recorded hospital records. Rates of OVD were analysed according to the TGCS, and the contribution of each group to the overall hospital population was calculated. RESULTS: There were 86 191 deliveries of women in our institution, of which 19.3% (16 673/86 191) had an OVD. Women in Group 1 (singleton, cephalic, nulliparous women at term in spontaneous labour) contributed the most to the overall rate of OVD, accounting for almost half of all OVDs (46.1% (7679/16 673)). Nulliparous women with a singleton, cephalic fetus at term who were induced (Group 2) were more likely to have an OVD than similar patients who laboured spontaneously (Group 1). CONCLUSION: OVD accounts for almost one in five deliveries in our population and is predominately performed in nulliparous women. These groups may be the subject of interventions to lower rates of OVD. The Robson TGCS is a freely available tool to hospitals and birthing centres to facilitate comparison of rates of OVD on local and national levels.

An abnormal cerebroplacental ratio (CPR) is predictive of early childhood delayed neurodevelopment in the setting of fetal growth restriction.

BACKGROUND: Fetal growth restriction accounts for a significant proportion of perinatal morbidity and death. The cerebroplacental ratio is gaining much interest as a useful tool in differentiating the "at-risk" fetus in both fetal growth restriction and appropriate-for-gestational-age pregnancies. The Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction group has demonstrated previously that the presence of this "brain-sparing" effect is associated significantly with adverse perinatal outcomes in the fetal growth restriction cohort. However, data about neurodevelopment in children from pregnancies that are complicated by fetal growth restriction are sparse and conflicting. OBJECTIVE: The aim of the Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction NeuroDevelopmental Assessment Study was to determine whether children born after fetal growth-restricted pregnancies are at additional risk of adverse early childhood developmental outcomes compared with children born small for gestational age. The objective of this secondary analysis was to describe the role of cerebroplacental ratio in the prediction of adverse early childhood neurodevelopmental outcome. STUDY DESIGN: Participants were recruited prospectively from the Perinatal Ireland multicenter observational Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction study cohort. Fetal growth restriction was defined as birthweight <10th percentile with abnormal antenatal umbilical artery Doppler indices. Small for gestational age was defined similarly in the absence of abnormal Doppler indices. Cerebroplacental ratio was calculated with the pulsatility indices of the middle cerebral artery and divided by umbilical artery with an abnormal value <1. Children (n=375) were assessed at 3 years with the use of the Ages and Stages Questionnaire and the Bayley Scales of Infant and Toddler Development, 3rd edition. Small-for-gestational-age pregnancies with normal Doppler indices were compared with (1) fetal growth-restricted cases with abnormal umbilical artery Doppler and normal cerebroplacental ratio or (2) fetal growth restriction cases with both abnormal umbilical artery and cerebroplacental ratio. Statistical analysis was performed with statistical software via 2-sample t-test with Bonferroni adjustment, and a probability value of .00625 was considered significant. RESULTS: Assessments were performed on 198 small-for-gestational-age children, 136 fetal growth-restricted children with abnormal umbilical artery Doppler images and normal cerebroplacental ratio, and 41 fetal growth-restricted children with both abnormal umbilical artery Doppler and cerebroplacental ratio. At 3 years of age, although there were no differences in head circumference, children who also had an abnormal cerebroplacental ratio had persistently shorter stature (P=.005) and lower weight (P=.18). Children from fetal growth restriction-affected pregnancies demonstrated poorer neurodevelopmental outcome than their small-for-gestational-age counterparts. Fetal growth-restricted pregnancies with an abnormal cerebroplacental ratio had significantly poorer neurologic outcome at 3 years of age across all measured variables. CONCLUSION: We have demonstrated that growth-restricted pregnancies with a cerebroplacental ratio <1 have a significantly increased risk of delayed neurodevelopment at 3 years of age when compared with pregnancies with abnormal umbilical artery Doppler evidence alone. This study further substantiates the benefit of routine assessment of cerebroplacental ratio in fetal growth-restricted pregnancies and for counseling parents regarding the long-term outcome of affected infants.

Evaluation of the Effect of Low-Dose Aspirin on Biochemical and Biophysical Biomarkers for Placental Disease in Low-Risk Pregnancy: Secondary Analysis of a Multicenter RCT.

OBJECTIVE: To assess the effect of aspirin use in low-risk pregnancy on: (1) pregnancy-associated plasma protein-A (PAPP-A) and placental-like growth factor (PLGF); (2) urinary albumin-to-creatinine ratio (ACR) and blood pressure; (3) fetal growth parameters; and (4) placental histopathology. STUDY DESIGN: This secondary analysis from the T rial of low-dose aspirin with an E arly S creening T est for preeclampsia and growth restriction randomized controlled trial was based on low-risk nulliparous women randomized at 11 weeks to (1) aspirin 75 mg; (2) no aspirin; and (3) aspirin based on the preeclampsia Fetal Medicine Foundation screening test. At baseline, women underwent assessment of blood pressure, PAPP-A, PLGF, and ACR, repeated 9 to 10 weeks postaspirin, in addition to fetal growth assessment. Gross and histopathological placental analyses were performed in line with Amsterdam criteria. RESULTS: A total of 445 subjects were included (aspirin n = 163 [36.6%]; no aspirin n = 282 [63.4%]). Although the fetal-to-placental weight ratio was significantly greater in the aspirin group (7.5 [±1.3] vs. 7.3 [±1.4], p = 0.045), as was change in ultrasound assessed estimated fetal weight from second to third trimesters (1,624.5 g [±235.1] vs. 1,606.2 [±189.4], p = 0.042), this was invalidated by the lack of a difference in birth weight. Aspirin did not significantly impact on change in serum or urine preeclampsia biomarkers, maternal blood pressure, or placental histopathology. CONCLUSION: Aspirin use in low-risk pregnancy does not appear to impact on preeclampsia biomarkers, fetal growth, or placental pathology.

The Impact of Aspirin on Ultrasound Markers of Uteroplacental Flow in Low-Risk Pregnancy: Secondary Analysis of a Multicenter RCT.

OBJECTIVE: This article evaluates the effect of low-dose aspirin on uterine artery (UtA) Doppler, placental volume, and vascularization flow indices in low-risk pregnancy. STUDY DESIGN: In this secondary analysis of the TEST randomized controlled trial, low-risk nulliparous women were originally randomized at 11 weeks to: (1) routine aspirin 75 mg; (2) no aspirin; and (3) aspirin based upon the preeclampsia Fetal Medicine Foundation screening test. UtA Doppler, three-dimensional (3D) placental volume, and vascularization flow indices were assessed prior to and 6 weeks postaspirin commencement. RESULTS: A total of 546 women were included (aspirin n = 192, no aspirin n = 354). Between first and second trimesters, aspirin use was not associated with a change in UtA Doppler, placental volume, or vascular flow indices. There was no significant difference in the change in UtA Doppler pulsatility index (PI) Z-scores or notching (PI Z-score -0.2 vs. -0.2, p = 0.17), nor was there a significant change in placental volume Z-score and vascular flow indices (volume Z-score change: 0.74 vs. 0.62, p = 0.34). CONCLUSION: Low-dose aspirin commenced at 11 weeks in low-risk women does not appear to improve uterine and placental perfusion or placental volume. Any perceived effect on uteroplacental vasculature is not reflected in changes in placental volume nor uteroplacental flow as assessed by two-dimensional and 3D ultrasound.

Genetic Variation, Magnesium Sulfate Exposure, and Adverse Neurodevelopmental Outcomes Following Preterm Birth.

OBJECTIVE: To evaluate the association of magnesium sulfate (MgSO4) exposure and candidate gene polymorphisms with adverse neurodevelopmental outcomes following preterm birth. STUDY DESIGN: We performed a nested case-control analysis of a randomized trial of maternal MgSO4 before anticipated preterm birth for the prevention of cerebral palsy (CP). Cases were children who died within 1 year of life or were survivors with abnormal neurodevelopment at age 2 years. Controls were race- and sex-matched survivors with normal neurodevelopment. We analyzed 45 candidate gene polymorphisms in inflammation, coagulation, and vascular regulation pathways and their association with (1) psychomotor delay, (2) mental delay, (3) CP, and (4) combined outcome of death/CP. Logistic regression analyses, conditional on maternal race and child sex, and adjusted for treatment group, gestational age at birth and maternal education, were performed. RESULTS: Four hundred and six subjects, 211 cases and 195 controls, were analyzed. The strongest association was for IL6R (rs 4601580) in which each additional copy of the minor allele was associated with an increased risk of psychomotor delay (adjusted odds ratio 3.3; 95% confidence interval, 1.7-6.5; p < 0.001). CONCLUSION: Candidate gene polymorphisms are associated with death and adverse neurodevelopmental outcomes following preterm birth. MgSO4 may abrogate this genotype association for some loci.

Evaluation of normalization of cerebro-placental ratio as a potential predictor for adverse outcome in SGA fetuses.

BACKGROUND: Intrauterine growth restriction accounts for a significant proportion of perinatal morbidity and mortality currently encountered in obstetric practice. The primary goal of antenatal care is the early recognition of such conditions to allow treatment and optimization of both maternal and fetal outcomes. Management of pregnancies complicated by intrauterine growth restriction remains one of the greatest challenges in obstetrics. Frequently, however, clinical evidence of underlying uteroplacental dysfunction may only emerge at a late stage in the disease process. With advanced disease the only therapeutic intervention is delivery of the fetus and placenta. The cerebroplacental ratio is gaining much interest as a useful tool in differentiating the at-risk fetus in both intrauterine growth restriction and the appropriate-for-gestational-age setting. The cerebroplacental ratio quantifies the redistribution of the cardiac output resulting in a brain-sparing effect. The Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction group previously demonstrated that the presence of a brain-sparing effect is significantly associated with an adverse perinatal outcome in the intrauterine growth restriction cohort. OBJECTIVE: The aim of the Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction study was to evaluate the optimal management of fetuses with an estimated fetal weight <10th centile. The objective of this secondary analysis was to evaluate if normalizing cerebroplacental ratio predicts adverse perinatal outcome. STUDY DESIGN: In all, 1116 consecutive singleton pregnancies with intrauterine growth restriction completed the study protocol over 2 years at 7 centers, undergoing serial sonographic evaluation and multivessel Doppler measurement. Cerebroplacental ratio was calculated using the pulsatility and resistance indices of the middle cerebral and umbilical artery. Abnormal cerebroplacental ratio was defined as <1.0. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death. RESULTS: Data for cerebroplacental ratio calculation were available in 881 cases, with a mean gestational age of 33 (interquartile range, 28.7-35.9) weeks. Of the 87 cases of abnormal serial cerebroplacental ratio with an initial value <1.0, 52% (n = 45) of cases remained abnormal and 22% of these (n = 10) had an adverse perinatal outcome. The remaining 48% (n = 42) demonstrated normalizing cerebroplacental ratio on serial sonography, and 5% of these (n = 2) had an adverse perinatal outcome. Mean gestation at delivery was 33.4 weeks (n = 45) in the continuing abnormal cerebroplacental ratio group and 36.5 weeks (n = 42) in the normalizing cerebroplacental ratio group (P value <.001). CONCLUSION: The Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction group previously demonstrated that the presence of a brain-sparing effect was significantly associated with an adverse perinatal outcome in our intrauterine growth restriction cohort. It was hypothesized that a normalizing cerebroplacental ratio would be a further predictor of an adverse outcome due to the loss of this compensatory mechanism. However, in this subanalysis we did not demonstrate an additional poor prognostic effect when the cerebroplacental ratio value returned to a value >1.0. Overall, this secondary analysis demonstrated the importance of a serial abnormal cerebroplacental ratio value of <1 within the <34 weeks' gestation population. Contrary to our proposed hypothesis, we recognize that reversion of an abnormal cerebroplacental ratio to a normal ratio is not associated with a heightened degree of adverse perinatal outcome.

Prediction of cesarean delivery in the term nulliparous woman: results from the prospective, multicenter Genesis study.

BACKGROUND: In contemporary practice many nulliparous women require intervention during childbirth such as operative vaginal delivery or cesarean delivery (CD). Despite the knowledge that the increasing rate of CD is associated with increasing maternal age, obesity and larger infant birthweight, we lack a reliable method to predict the requirement for such potentially hazardous obstetric procedures during labor and delivery. This issue is important, as there are greater rates of morbidity and mortality associated with unplanned CD performed in labor compared with scheduled CDs. A prediction algorithm to identify women at risk of an unplanned CD could help reduced labor associated morbidity. OBJECTIVE: In this primary analysis of the Genesis study, our objective was to prospectively assess the use of prenatally determined, maternal and fetal, anthropomorphic, clinical, and ultrasound features to develop a predictive tool for unplanned CD in the term nulliparous woman, before the onset of labor. MATERIALS AND METHODS: The Genesis study recruited 2336 nulliparous women with a vertex presentation between 39+0 and 40+6 weeks' gestation in a prospective multicenter national study to examine predictors of CD. At recruitment, a detailed clinical evaluation and ultrasound assessment were performed. To reduce bias from knowledge of these data potentially influencing mode of delivery, women, midwives, and obstetricians were blinded to the ultrasound data. All hypothetical prenatal risk factors for unplanned CD were assessed as a composite. Multiple logistic regression analysis and mathematical modeling was used to develop a risk evaluation tool for CD in nulliparous women. Continuous predictors were standardized using z scores. RESULTS: From a total enrolled cohort of 2336 nulliparous participants, 491 (21%) had an unplanned CD. Five parameters were determined to be the best combined predictors of CD. These were advancing maternal age (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.09 to 1.34), shorter maternal height (OR, 1.72; 95% CI, 1.52 to 1.93), increasing body mass index (OR, 1.29; 95% CI, 1.17 to 1.43), larger fetal abdominal circumference (OR, 1.23; 95% CI, 1.1 to 1.38), and larger fetal head circumference (OR, 1.27; 95% CI, 1.14 to 1.42). A nomogram was developed to provide an individualized risk assessment to predict CD in clinical practice, with excellent calibration and discriminative ability (Kolmogorov-Smirnov, D statistic, 0.29; 95% CI, 0.28 to 0.30) with a misclassification rate of 0.21 (95% CI, 0.19 to 0.25). CONCLUSION: Five parameters (maternal age, body mass index, height, fetal abdominal circumference, and fetal head circumference) can, in combination, be used to better determine the overall risk of CD in nulliparous women at term. A risk score can be used to inform women of their individualized probability of CD. This risk tool may be useful for reassuring most women regarding their likely success at achieving an uncomplicated vaginal delivery as well as selecting those patients with such a high risk for CD that they should avoid a trial of labor. Such a risk tool has the potential to greatly improve planning hospital service needs and minimizing patient risk.

Prenatal prediction of significant intertwin birthweight discordance using standard second and third trimester sonographic parameters.

INTRODUCTION: Our study aim was to evaluate standard ultrasound-derived fetal biometric parameters in the prediction of clinically significant intertwin birthweight discordance defined as ≥18%. MATERIAL AND METHODS: This was a secondary analysis of a prospective cohort study of 1028 unselected twin pairs recruited over a two-year period. Dichorionic twins underwent two-weekly ultrasonographic surveillance from 24 weeks' gestation, with surveillance of monochorionic twins two-weekly from 16 weeks. Ultrasonographic biometric data from 24 to 36 weeks were evaluated for the prediction of an intertwin birthweight discordance threshold ≥18%. Umbilical artery Doppler waveform data was also analyzed to evaluate whether it was predictive of birthweight discordance. RESULTS: Of the 956 twin pairs analyzed for discordance, 208 pairs were found to have a clinically significant birthweight discordance ≥18%. All biometric parameters were predictive of significant inter-twin birthweight discordance at low cut-offs, with low discriminatory powers when ROC curves were analyzed. Discordance in estimated fetal weight was predictive of a significant birthweight discordance at all gestational categories with cut-offs between 8 and 11%. A low-discriminatory power and poor sensitivity and specificity were also observed. An abnormal umbilical artery Doppler was predictive of birthweight discordance ≥18% between 28 and 32 weeks' gestation, although with poor sensitivity and specificity. CONCLUSIONS: Calculation of estimated fetal weight and birthweight discordance between twins allows minimal margin for error. These margins make it difficult to accurately predict those who are at or above the discordance threshold of 18%. These findings highlight that small intertwin discrepancies in weight and biometry should not be overlooked and merit further investigation.

Neuro-developmental outcome of a large cohort of growth discordant twins.

UNLABELLED: Our aims were to study the effect of birthweight growth discordance (≥20%) on neuro-developmental outcome of monochorionic and dichorionic twins and to compare the relative effects of foetal growth discordance and prematurity on cognitive outcome. We performed a cross-sectional multicentre prospective follow-up study from a cohort of 948 twin pregnancies. One hundred nineteen birthweight-discordant twin pairs were examined (24 monochorionic pairs) and were matched for gestational age at delivery with 111 concordant control pairs. Participants were assessed with the Bayley Scales between 24 and 42 months of age. Analysis was by paired t test for intra-twin pair differences and by multiple linear regression. Compared to the larger twin of a discordant pair, the smaller twin performed significantly worse in cognition (mean composite cognitive score difference = -1.7, 95% confidence interval (CI) = 0.3-3.1, p = 0.01) and also in language and motor skills. Prematurity prior to 33 weeks' gestation, however, had a far greater impact on cognitive outcomes (mean cognitive composite score difference = -5.8, 95% CI = 1.2-10.5, p = 0.008). CONCLUSION: Birthweight growth discordance of ≥20% confers an independent adverse effect on long-term neuro-development of the smaller twin. However, prior to 33 weeks' gestation, gestational age at birth adversely affects cognitive development to a greater extent than foetal growth discordance.

Improved Perinatal Mortality in Twins--Changing Practice and Technologies.

OBJECTIVE: We set out to examine rates of perinatal mortality in twin pregnancies over a 17-year study period. Changes in mode of delivery were also examined as well as causes of death in twin mortalities. STUDY DESIGN: This retrospective cohort study was performed at three large tertiary referral centers from 1996 to 2012. It included all normally formed twin infants with a birth weight more than 500 g. All cases of perinatal mortality in twin pregnancies (infants more than 500 g who suffered an intrauterine or early neonatal (≤ 7 days of age) death were recorded. The changing rate of cesarean delivery as well as varying causes of death in twins over the course of the study were also examined. RESULTS: During the study period, there were 395,830 pregnancies across the three institutions, this included 6,727 twin gestations. The perinatal mortality rate was 21.5/1,000 twin infants. The perinatal mortality rate in twins decreased over the study period (p = 0.0006; R (2) = 0.55; slope = -1.2). Rates of cesarean delivery in twin gestations were found to have increased over the course of the study (p < 0.0001; R (2) = 0.84; slope = 1.7). There were 288 intrauterine and early neonatal deaths in twin infants, 50% (147/288) occurred in twins born extremely premature (< 26 weeks). Prematurity was the leading cause of mortality in twins, followed by twin-to-twin transfusion syndrome (TTTS). TTTS was found to have a decreasing contribution to perinatal mortality during the study (p = 0.008; R (2) = 0.38; slope = -1.5). CONCLUSION: The perinatal mortality rate in twins improved during the study. The rate of cesarean delivery increased by 1.7% for each year of the study, culminating in a cesarean delivery rate of 62% in 2012. TTTS made a decreasing contribution to the mortality rate in twins during the study.

Altered Platelet Function in Intrauterine Growth Restriction: A Cause or a Consequence of Uteroplacental Disease?

Objective A limited number of platelet function studies in intrauterine growth restriction (IUGR) have yielded conflicting results. We sought to evaluate platelet reactivity in IUGR using a novel platelet aggregation assay. Study Design Pregnancies with IUGR were recruited from 24 weeks' gestation (estimated fetal weight < 10th centile) and had platelet function testing performed after diagnosis. A modification of light transmission aggregometry created dose-response curves of platelet reactivity in response to multiple agonists at differing concentrations. Findings were compared with healthy third trimester controls. IUGR cases with a subsequent normal birth weight were analyzed separately. Results In this study, 33 pregnancies retained their IUGR diagnosis at birth, demonstrating significantly reduced platelet reactivity in response to all agonists (arachidonic acid, adenosine diphosphate, collagen, thrombin receptor-activating peptide, and epinephrine) when compared with 36 healthy pregnancy controls (p < 0.0001). Similar results were obtained for cases demonstrating an increasing in utero growth trajectory. When IUGR preceded preeclampsia or gestational hypertension, platelet function was significantly reduced compared with normotensive IUGR. Conclusion Using this comprehensive platelet assay, we have demonstrated a functional impairment of platelets in IUGR. This may reflect platelet-derived placental growth factor release. Further evaluation of platelet function may aid in the development of future platelet-targeted therapies for uteroplacental disease.

Gestational hypertensive disease in twin pregnancy: Influence on outcomes in a large national prospective cohort.

OBJECTIVE: Gestational hypertensive disease (GHD) is associated with pregnancy-related complications and poor maternal and fetal outcomes in singleton pregnancies. We sought to examine the influence of GHD in a large prospective cohort of twin pregnancies. STUDY DESIGN: The ESPRIT study was a national multicenter observational cohort study of 1028 structurally normal twin pregnancies. Each pregnancy underwent sonographic surveillance with two-week ultrasound from 24 weeks for dichorionic and from 16 weeks for monochorionic gestations. Characteristics and demographics as well as labour and delivery outcome data were prospectively recorded. Perinatal mortality, admission to the neonatal intensive care unit (NICU) and a composite of morbidity of respiratory distress syndrome, hypoxic ischaemic encephalopathy, periventricular leukomalacia, necrotising enterocolitis and sepsis were documented for all cases. Outcomes for patients with documented GHD (pre-eclampsia and gestational hypertension) were compared with those without GHD. RESULTS: Perinatal outcome data were recorded for 977 patients. Women with GHD had a higher body mass index (27.1 ± 6.4 vs 25.2 ± 4.5, P < 0.0001) than those without and were more likely to be nulliparous (65% (59/92) vs 46% (407/885), P = 0.001). Both groups had similar mean birthweights, but those with GHD were more likely to have a birthweight discordance ≥18% (35% (32/92) vs 20% (179/885), P = 0.001). Rates of caesarean delivery were higher in those twin pregnancies affected by GHD, and while the rate of composite morbidity was similar in both groups, twins in the GHD group had higher rates of NICU admission. CONCLUSION: In twin gestations, gestational hypertension independently confers an increased risk for emergency caesarean delivery, birthweight discordance and NICU admission, such that intensive maternal-fetal monitoring is justified when hypertension develops in a twin pregnancy.

The effect of maternal obesity on sonographic fetal weight estimation and perinatal outcome in pregnancies complicated by fetal growth restriction.

PURPOSE: Maternal obesity represents a challenge in the sonographic (US) assessment of fetal weight, and is a recognized risk factor for adverse pregnancy outcome. The objective of this secondary analysis of data from the Prospective Observational Trial to Optimize Pediatric Health in fetal growth restriction (FGR) Study (PORTO) was to describe the effect of maternal obesity on the accuracy of US in determining the estimated fetal weight (EFW) and the perinatal outcome of pregnancies affected by FGR. METHODS: Between 2010 and 2012, 1,116 women with nonanomalous singleton pregnancies with an EFW in less than the tenth centile were recruited for the PORTO study. Maternal body mass index (BMI) was divided into five subcategories: normal (BMI < 24.9 kg/m(2) ), overweight (25-29.9), obese class 1 (30-34.9), obese class 2 (35-39.9), and obese class 3 (>40). The accuracy of the EFW was determined in women who delivered within 2 weeks of their last US scan. Perinatal outcomes were analyzed by BMI subcategory. RESULTS: Of the 1,074 patients with complete records, 691 (64%) were of normal weight, 258 (24%) were overweight, 93 (9%) were in obese class 1, 32 (3%) were in obese class 2, and none were in obese class 3. Overall, the EFW determined prior to delivery was within 6% of the actual birth weight in all BMI subcategories. Overweight and obese women delivered more commonly by cesarean section and at earlier gestational ages than did women with a normal BMI (p = 0.0008), resulting in lower birth weights (p = 0.0031) and significantly increased composite perinatal morbidity (p < 0.0001) and mortality (p = 0.0215) rates. CONCLUSIONS: US examination is reliable for assessing the weight of fetuses with FGR in overweight women. Maternal obesity, however, has a significant adverse effect on perinatal outcomes. Thus, health education should focus on awareness of this adverse effect, with optimization of prepregnancy weight as its main goal.

Antenatal Magnesium and Cerebral Palsy in Preterm Infants.

OBJECTIVE: To evaluate the relationship of maternal antenatal magnesium sulfate (MgSO4) with neonatal cranial ultrasound abnormalities and cerebral palsy (CP). STUDY DESIGN: In a randomized trial of MgSO4 or placebo in women at high risk of preterm delivery, up to 3 cranial ultrasounds were obtained in the neonatal period. Images were reviewed by at least 2 pediatric radiologists masked to treatment and other clinical conditions. Diagnoses were predefined for intraventricular hemorrhage, periventricular leukomalacia, intracerebral echolucency or echodensity, and ventriculomegaly. CP was diagnosed at 2 years of age by standardized neurologic examination. RESULTS: Intraventricular hemorrhage, periventricular leukomalacia, intracerebral echolucency or echodensity, and ventriculomegaly were all strongly associated with an increased risk of CP. MgSO4 administration did not affect the risk of cranial ultrasound abnormality observed at 35 weeks postmenstrual age or later. However, for the 82% of infants born at <32 weeks gestation, MgSO4 was associated with a reduction in risk of echolucency or echodensity. The reduction in risk for echolucency explained 21% of the effect of MgSO4 on CP (P = .04), and for echodensity explained 20% of the effect (P = .02). CONCLUSIONS: MgSO4 given prior to preterm delivery was associated with decreased risk of developing echodensities and echolucencies at <32 weeks gestation. However, this effect can only partially explain the effect of MgSO4 on CP at 2 years of age. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00014989.

Dichorionic twin ultrasound surveillance: sonography every 4 weeks significantly underperforms sonography every 2 weeks: results of the Prospective Multicenter ESPRiT Study.

OBJECTIVE: A 2-week ultrasound scanning schedule for monochorionic twins is endorsed widely. There is a lack of robust data to inform a schedule for the surveillance of dichorionic gestations. We aimed to determine how ultrasound scanning that is performed at 2- or 4-week intervals (or every 4 weeks before 32 weeks' gestation and every 2 weeks thereafter) may impact the prenatal detection of fetal growth restriction (FGR) and ultimately influence timing of delivery. STUDY DESIGN: In a consecutive cohort of 789 dichorionic twin pregnancies that were recruited prospectively for the multicenter Evaluation of Sonographic Predictors of Restricted Growth in Twins study, ultrasound determination of fetal growth and interrogation of umbilical and middle cerebral artery Doppler scans were performed every 2 weeks from 24 weeks' gestation until delivery. Complete delivery and perinatal outcome data were recorded for all pregnancies. Where delivery was prompted by FGR, abnormal umbilical artery Doppler examination or poor biophysical profile and in the absence of ruptured membranes, onset of labor, preeclampsia, or antepartum hemorrhage, the delivery was considered "ultrasound-indicated." For ultrasound-indicated deliveries, detection probabilities for FGR/abnormal umbilical artery Doppler scans/poor biophysical were determined according to the interval between examinations, by the suppression if alternate examination data. RESULTS: Among 789 dichorionic twin pregnancies, 66 pairs (8%) had an "ultrasound indicated" delivery. Detection of FGR was reduced from 88-69%, and detection of abnormal umbilical artery Doppler was reduced from 82-62% when a 4-week ultrasound schedule was simulated. Both of these reductions reached statistical significance. There was a nonsignificant trend toward a reduction in the recording of oligohydramnios with a 4-week interval between examinations. CONCLUSION: This study suggests that the ultrasound surveillance program of every 2 weeks that is recommended currently for monochorionic twins should be extended to dichorionic gestations.