MRI analysis of neurodevelopmental anatomy in myelomeningocele: prenatal vs postnatal repair.

OBJECTIVE: Prenatal myelomeningocele (MMC) repair offers improved motor function and decreased rates of cerebrospinal fluid (CSF) diversion compared to than postnatal repair. However, comparative analysis of other associated neuroanatomical findings is lacking. The purpose of this study is to use magnetic resonance imaging (MRI) imaging to compare characteristic Chiari II malformation stigmata in patients who underwent fetal MMC repair vs. postnatal repair. METHODS: A retrospective review was performed of neonates who underwent prenatal or postnatal MMC repair at our institution and had postnatal MRIs. We analyzed anatomical findings characteristically seen with Chiari II malformation on brain MRI in patients who underwent prenatal MMC repair vs. postnatal repair. RESULTS: CSF diversion was required in 24% of prenatal cohort vs. 67% of postnatal cohort (p = 0.002), and syrinx was present in 12% of prenatal cohort compared to 42% in postnatal cohort (p = 0.03). Corpus callosum (CC) morphology was abnormal in 52% of prenatal cohort vs. 53% of postnatal cohort (p = 0.92), while falx morphology was normal in 92% of the prenatal cohort vs. 34% of the postnatal cohort (p = <0.001). Prenatal cohort patients had shorter tentorium to foramen magnum distance than postnatal cohort patients (18.4mm vs. 22.4mm, p = 0.01), overall larger foramen magnum diameter (22.9mm vs. 18.9mm, p < 0.001), and a smaller mean degree of hindbrain herniation (1.5mm vs. 8.7mm, p < 0.001). Finally, the cerebral aqueduct was patent in 79% of prenatal cohort vs. 100% of postnatal cohort (p = 0.007). There was no significant difference in presence of gray matter heterotopia, presence of septum pellucidum, or size of massa intermedia between the two cohorts. CONCLUSIONS: We report baseline variations in developmental neuroanatomy in patients with MMC including rates of CC dysgenesis, gray matter heterotopia and additional cranial and spinal MRI findings. We found that prenatal surgery results in changes to infratentorial anatomy, with minimal effect on supratentorial brain development. This information will be useful in myelomeningocele counseling and in understanding how prenatal repair of myelomeningocele affects brain development. This article is protected by copyright. All rights reserved.

Consensus protocol for management of early and late twin-twin transfusion syndrome: Delphi study.

OBJECTIVE: Fetoscopic laser photocoagulation (FLP) is a well-established treatment for twin-twin transfusion syndrome (TTTS) between 16 and 26 weeks' gestation. High-quality evidence and guidelines regarding the optimal clinical management of very early (prior to 16 weeks), early (between 16 and 18 weeks) and late (after 26 weeks) TTTS are lacking. The aim of this study was to construct a structured expert-based clinical consensus for the management of early and late TTTS. METHODS: A Delphi procedure was conducted among an international panel of experts. Participants were chosen based on their clinical expertise, affiliation and relevant publications. A four-round Delphi survey was conducted using an online platform and responses were collected anonymously. In the first round, a core group of experts was asked to answer open-ended questions regarding the indications, timing and modes of treatment for early and late TTTS. In the second and third rounds, participants were asked to grade each statement on a Likert scale (1, completely disagree; 5, completely agree) and to add any suggestions or modifications. At the end of each round, the median score for each statement was calculated. Statements with a median grade of 5 without suggestions for change were accepted as the consensus. Statements with a median grade of 3 or less were excluded from the Delphi process. Statements with a median grade of 4 were modified according to suggestions and reconsidered in the next round. In the last round, participants were asked to agree or disagree with the statements, and those with more than 70% agreement without suggestions for change were considered the consensus. RESULTS: A total of 122 experts met the inclusion criteria and were invited to participate, of whom 53 (43.4%) agreed to take part in the study. Of those, 75.5% completed all four rounds. A consensus on the optimal management of early and late TTTS was obtained. FLP can be offered as early as 15 weeks' gestation for selected cases, and can be considered up to 28 weeks. Between 16 and 18 weeks, management should be tailored according to Doppler findings. CONCLUSIONS: A consensus-based treatment protocol for early and late TTTS was agreed upon by a panel of experts. This protocol should be modified at the discretion of the operator, according to their experience and the specific demands of each case. This should advance the quality of future studies, guide clinical practice and improve patient care. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Association of intraplacental oxygenation patterns on dual-contrast MRI with placental abnormality and fetal brain oxygenation.

OBJECTIVES: Most human in-vivo placental imaging techniques are unable to distinguish and characterize various placental compartments, such as the intervillous space (IVS), placental vessels (PV) and placental tissue (PT), limiting their specificity. We describe a method that employs T2* and diffusion-weighted magnetic resonance imaging (MRI) data to differentiate automatically placental compartments, quantify their oxygenation properties and identify placental lesions (PL) in vivo. We also investigate the association between placental oxygenation patterns and fetal brain oxygenation. METHODS: This was a prospective study conducted between 2018 and 2021 in which dual-contrast clinical MRI data (T2* and diffusion-weighted MRI) were acquired from patients between 20 and 38 weeks' gestation. We trained a fuzzy clustering method to analyze T2* and diffusion-weighted MRI data and assign placental voxels to one of four clusters, based on their distinct imaging domain features. The new method divided automatically the placenta into IVS, PV, PT and PL compartments and characterized their oxygenation changes throughout pregnancy. RESULTS: A total of 27 patients were recruited, of whom five developed pregnancy complications. Total placental oxygenation level and T2* did not demonstrate a statistically significant temporal correlation with gestational age (GA) (R2 = 0.060, P = 0.27). In contrast, the oxygenation level reflected by T2* values in the placental IVS (R2 = 0.51, P = 0.0002) and PV (R2 = 0.76, P = 1.1 × 10-7 ) decreased significantly with advancing GA. Oxygenation levels in the PT did not show any temporal change during pregnancy (R2 = 0.00044, P = 0.93). A strong spatial-dependent correlation between PV oxygenation level and GA was observed. The strongest negative correlation between PV oxygenation and GA (R2 = 0.73, P = 4.5 × 10-7 ) was found at the fetal-vessel-dominated region close to the chorionic plate. The location and extent of the placental abnormality were automatically delineated and quantified in the five women with clinically confirmed placental pathology. Compared to the averaged total placental oxygenation, placental IVS oxygenation level best reflected fetal brain oxygenation level during fetal development. CONCLUSION: Based on clinically feasible dual-MRI, our method enables accurate spatiotemporal quantification of placental compartment and fetal brain oxygenation across different GAs. This information should improve our knowledge of human placenta development and its relationship with normal and abnormal pregnancy. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Frequency and prediction of persistent urinary tract dilation in third trimester and postnatal urinary tract dilation in infants following diagnosis in second trimester.

OBJECTIVE: To determine the frequency, associated characteristics and prognostic value of the current risk stratification system for prenatal urinary tract dilation (UTD) for predicting persistent UTD in the third trimester and subsequent postnatal UTD in the infant, following diagnosis in the second trimester. METHODS: This was a single-institution retrospective cohort study of singleton pregnancies diagnosed with unilateral or bilateral UTD in the second trimester (before 28 weeks' gestation) with follow-up in the third trimester (at or after 28 weeks) between January 2017 and May 2019. In all cases, the prenatal diagnosis and stratification to low-risk (Grade A1) or increased-risk (Grade A2-3) UTD was made using the 2014 UTD consensus classification system. The primary outcomes included persistent prenatal UTD in the third trimester and postnatal UTD up to 6 months of age. We performed multivariable analysis to assess whether patient and second- and third-trimester sonographic characteristics (such as UTD laterality, other renal abnormality (calyceal dilation, abnormal parenchymal appearance, abnormal ureter or bladder) and anteroposterior renal pelvic diameter (AP-RPD)) were associated with the study outcomes. We assessed the predictive value of the current risk stratification system (Grade A1 vs Grade A2-3) in the second and third trimesters for persistent prenatal UTD and postnatal UTD using the area under the receiver-operating-characteristics curve (AUC). RESULTS: Of 26 620 second-trimester ultrasound assessments in the study period, 347 patients were diagnosed with UTD in the second trimester and had third-trimester follow-up, of whom 150/347 (43% (95% CI, 38-49%)) had persistent UTD in the third trimester. Among the 282/347 (81%) patients with postnatal follow-up available, the frequency of postnatal UTD was 49/282 (17% (95% CI, 13-22%)), and among the subset with persistent UTD in the third trimester, the frequency of postnatal UTD was 46/102 (45% (95% CI, 35-55%)). The most frequent postnatal diagnosis was transient UTD (76%), followed by duplicated collecting system (10%). Of infants originally diagnosed with UTD in the second trimester, 2% (7/347) required surgery; stated differently, of the 49 infants with postnatal UTD, 14% (7/49) required surgery. At second-trimester diagnosis, sonographic predictors of both persistent prenatal UTD and postnatal UTD included the presence of other renal abnormality and UTD Grade A2-3. At third-trimester follow-up, predictors of postnatal UTD were larger mean AP-RPD and UTD Grade A2-3, while all cases had other renal abnormality. Second-trimester diagnosis of UTD Grade A2-3 had satisfactory discrimination for predicting persistent prenatal UTD (AUC, 0.64 (95% CI, 0.58-0.70)) and postnatal UTD (AUC, 0.72 (95% CI, 0.63-0.81)), as did third-trimester UTD Grade A2-3 for predicting postnatal UTD (AUC, 0.66 (95% CI, 0.56-0.76)). CONCLUSIONS: The majority of cases of prenatal UTD did not result in postnatal UTD, and of those that did, very few required surgery. Follow-up third-trimester assessment after a second-trimester diagnosis of UTD is warranted. The current risk stratification system by UTD grade, based on the 2014 UTD consensus classification, can be used to predict postnatal UTD with fair accuracy. Further research is needed to determine whether the predictive performance of this system can be improved by incorporating additional risk factors. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Reference ranges for fetal brain structures using magnetic resonance imaging: systematic review.

OBJECTIVE: To evaluate the methodology of studies reporting reference ranges for fetal brain structures on magnetic resonance imaging (MRI). METHODS: MEDLINE, EMBASE, CINAHL and the Web of Science databases were searched electronically up to 31 December 2020 to identify studies investigating biometry and growth of the fetal brain and reporting reference ranges for brain structures using MRI. The primary aim was to evaluate the methodology of these studies. A list of 26 quality criteria divided into three domains, including 'study design', 'statistical and reporting methods' and 'specific aspects relevant to MRI', was developed and applied to evaluate the methodological appropriateness of each of the included studies. The overall quality score of a study, ranging between 0 and 26, was defined as the sum of scores awarded for each quality criterion and expressed as a percentage (the lower the percentage, the higher the risk of bias). RESULTS: Fifteen studies were included in this systematic review. The overall mean quality score of the studies evaluated was 48.7%. When focusing on each domain, the mean quality score was 42.0% for 'study design', 59.4% for 'statistical and reporting methods' and 33.3% for 'specific aspects relevant to MRI'. For the 'study design' domain, sample size calculation and consecutive enrolment of women were the items found to be at the highest risk of bias. For the 'statistical and reporting methods' domain, the presence of regression equations for mean and SD for each measurement, the number of measurements taken for each variable and the presence of postnatal assessment information were the items found to be at the highest risk of bias. For the 'specific aspects relevant to MRI' domain, whole fetal brain assessment was not performed in any of the included studies and was therefore considered to be the item at the highest risk of bias. CONCLUSIONS: Most of the previously published studies reporting fetal brain reference ranges on MRI are highly heterogeneous and have low-to-moderate quality in terms of methodology, which is similar to the findings reported for ultrasound studies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Longitudinal assessment of spiral artery and intravillous arteriole blood flow and adverse pregnancy outcome.

OBJECTIVE: Superb microvascular imaging (SMI) has been shown to improve visualization of small vessels by suppressing global motions while preserving low-flow components, such as the microvessels in the placenta. We sought to determine if SMI-aided visualization of flow velocity waveforms in the spiral arteries (SA) and intravillous fetal arterioles (IVA) could predict fetal growth restriction (FGR), gestational hypertension (GH) and/or pre-eclampsia (PE). METHODS: This was a prospective longitudinal study of singleton pregnancies without fetal anomaly, receiving prenatal care in one of two medical centers over a 5-year period. Using SMI-aided color Doppler, SA and IVA flow velocity was measured at three timepoints: 11 + 0 to 14 + 0, 18 + 0 to 22 + 6 and 28 + 0 to 34 + 6 weeks of gestation. SA and IVA flow velocity waveforms were reported as resistance indices (RI). RI values were analyzed using multilevel modeling; individual regression curves were estimated and combined to obtain the reference intervals for SA-RI and IVA-RI in uncomplicated pregnancies. The primary clinical outcome was FGR and secondary outcomes were PE and GH. FGR was defined as estimated fetal weight < 10th percentile. Student's t-test was used to compare deviation from expected RI between normal and complicated pregnancies. RESULTS: Among 540 pregnancies included in the analysis, 18 (3.3%) had FGR, 31 (5.7%) PE and 61 (11.3%) GH. In uncomplicated pregnancies, the SA-RI decreased progressively with advancing gestation, whereas the IVA-RI increased with gestational age. In the third trimester, the mean SA-RI and IVA-RI values were significantly higher in the FGR group compared with pregnancies that did not develop FGR, while the mean SA-RI was significantly higher in PE compared with non-PE pregnancies. There was no significant difference in mean SA-RI or IVA-RI between pregnancies with vs those without GH at any gestational age. When all three adverse outcomes were combined, SA-RI was significantly higher in pregnancies with these outcomes when compared to uncomplicated pregnancies in the third trimester (mean ± SD, 0.29 ± 0.12 vs 0.26 ± 0.12; P = 0.02). In screening for FGR using SA-RI, the areas under the receiver-operating-characteristics curves (AUC) were 0.68, 0.73 and 0.73 in the first, second and third trimesters, respectively. The respective AUCs for IVA-RI were 0.72, 0.72 and 0.73 for each trimester. CONCLUSIONS: SA-RI and IVA-RI, measured using SMI technology, were significantly higher in pregnancies at risk for FGR in late gestation. Larger studies are needed to determine if SA and IVA flow are reliable predictors of adverse pregnancy outcome. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Outcome-based comparison of SMFM and ISUOG definitions of fetal growth restriction.

OBJECTIVE: The recent international guidelines by the Society for Maternal-Fetal Medicine (SMFM) and the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) differ in their definitions of fetal growth restriction (FGR). Our aim was to compare the performance of the two definitions in predicting neonatal small-for-gestational age (SGA) and composite adverse neonatal outcome (ANO). METHODS: This was a secondary analysis of data from a prospective study of women referred for fetal growth ultrasound examination between 26 + 0 and 36 + 6 weeks' gestation. The SMFM and ISUOG guidelines were used to define pregnancies with FGR. The SMFM definition of FGR is estimated fetal weight (EFW) or abdominal circumference (AC) < 10th percentile. The ISUOG-FGR definition follows the Delphi consensus criteria and includes either EFW or AC < 3rd percentile or EFW or AC < 10th percentile combined with abnormal Doppler findings or a decrease in growth centiles. The primary outcome was the prediction of neonatal SGA, defined as birth weight < 10th percentile, and a composite of ANO, which was defined as one or more of: Grade-III or -IV intraventricular hemorrhage, respiratory distress syndrome, neonatal death, cord blood pH < 7.1, seizures and admission to the neonatal intensive care unit. Test characteristics (sensitivity, specificity, positive predictive value (PPV), negative predictive value and positive (LR+) and negative likelihood ratios) and area under the receiver-operating-characteristics curve were determined. The association between FGR detected by each definition and selected adverse outcomes was assessed using logistic regression analysis. RESULTS: Of the 1054 pregnancies that met the inclusion criteria, 137 (13.0%) and 55 (5.2%) were defined as having FGR by the SMFM and ISUOG definitions, respectively. Composite ANO and SGA neonate each occurred in 139 (13.2%) pregnancies. For the prediction of neonatal SGA, the SMFM-FGR definition had a higher sensitivity (54.7%) than did the ISUOG definition (28.8%). The ISUOG-FGR definition had higher specificity (98.4% vs 93.3%), LR+ (18.0 vs 8.2) and PPV (72.7% vs 55.5%) than did the SMFM definition for the prediction of a SGA neonate. The SMFM- and ISUOG-FGR definitions had similarly poor performance in predicting composite ANO, with sensitivities of 15.1% and 10.1%, respectively. CONCLUSIONS: The SMFM definition of FGR is associated with a higher detection rate for SGA neonates but at the cost of some reduction in specificity. The ISUOG-FGR definition has a higher specificity, LR+ and PPV for the prediction of neonatal SGA. Both definitions of FGR performed poorly in predicting a composite ANO. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Counseling in maternal-fetal medicine: SARS-CoV-2 infection in pregnancy.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a zoonotic coronavirus that crossed species to infect humans, causing coronavirus disease 2019 (COVID-19). Despite a potentially higher risk of pregnant women acquiring SARS-CoV-2 infection compared with the non-pregnant population (particularly in some ethnic minorities), no additional specific recommendations to avoid exposure are needed in pregnancy. The most common clinical symptoms and laboratory signs of SARS-CoV-2 infection in pregnancy are fever, cough, lymphopenia and elevated C-reactive protein levels. Pregnancy is associated with a higher risk of severe SARS-CoV-2 infection compared with the non-pregnant population, including pneumonia, admission to the intensive care unit and death, even after adjusting for potential risk factors for severe outcomes. The risk of miscarriage does not appear to be increased in women with SARS-CoV-2 infection. Evidence with regards to preterm birth and perinatal mortality is conflicting, but these risks are generally higher only in symptomatic, hospitalized women. The risk of vertical transmission, defined as the transmission of SARS-CoV-2 from the mother to the fetus or the newborn, is generally low. Fetal invasive procedures are considered to be generally safe in pregnant women with SARS-CoV-2 infection, although the evidence is still limited. In pregnant women with COVID-19, use of steroids should not be avoided if clinically indicated; the preferred regimen is a 2-day course of dexamethasone followed by an 8-day course of methylprednisolone. Non-steroidal anti-inflammatory drugs may be used if there are no contraindications. Hospitalized pregnant women with severe COVID-19 should undergo thromboprophylaxis throughout the duration of hospitalization and at least until discharge, preferably with low molecular weight heparin. Hospitalized women who have recovered from a period of serious or critical illness with COVID-19 should be offered a fetal growth scan about 14 days after recovery from their illness. In asymptomatic or mildly symptomatic women who have tested positive for SARS-CoV-2 infection at full term (i.e. ≥ 39 weeks of gestation), induction of labor might be reasonable. To date, there is no clear consensus on the optimal timing of delivery for critically ill women. In women with no or few symptoms, management of labor should follow routine evidence-based guidelines. Regardless of COVID-19 status, mothers and their infants should remain together and breastfeeding, skin-to-skin contact, kangaroo mother care and rooming-in throughout the day and night should be practiced, while applying necessary infection prevention and control measures. Many pregnant women have already undergone vaccination, mostly in the USA where the first reports show no significant difference in pregnancy outcomes in pregnant women receiving SARS-CoV-2 vaccination during pregnancy compared with the background risk. Vaccine-generated antibodies were present in the umbilical cord blood and breast milk samples of pregnant and lactating women who received the mRNA COVID-19 vaccine. Based on the available limited data on the safety of the COVID-19 vaccine in pregnancy, it seems reasonable to offer the option of vaccination to pregnant women after accurate counseling on the potential risk of a severe course of the disease and the unknown risk of fetal exposure to the vaccine. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Validation of Delphi procedure consensus criteria for defining fetal growth restriction.

OBJECTIVE: Recently, a Delphi procedure was used to establish new criteria for defining fetal growth restriction (FGR). These criteria require clinical validation. We sought to validate the Delphi consensus criteria by comparing their performance with that of our current definition (estimated fetal weight (EFW) < 10th percentile) in predicting adverse neonatal outcome (ANO). METHODS: This was a secondary analysis of data from a prospective cohort study of women referred for fetal growth assessment between 26 and 36 weeks' gestation. The current standard definition of FGR used in our clinical practice is EFW < 10th percentile using Hadlock's fetal growth standard. The Delphi consensus criteria for FGR include either a very small fetus (abdominal circumference (AC) or EFW < 3rd percentile) or a small fetus (AC or EFW < 10th percentile) with additional abnormal Doppler findings or a decrease in AC or EFW by two quartiles or more. The primary outcome was the prediction of a composite of ANO including one or more of: admission to the neonatal intensive care unit, cord pH < 7.1, 5-min Apgar score < 7, respiratory distress syndrome, intraventricular hemorrhage, neonatal seizures or neonatal death. The discriminatory capacities of the two definitions of FGR for composite ANO and delivery of a small-for-gestational-age (SGA) neonate, defined as birth weight < 10th percentile, were compared using area under the receiver-operating-characteristics curve (AUC). The sensitivity, specificity and predictive values of the methods were also compared. RESULTS: Of 1055 pregnancies included in the study, composite ANO occurred in 139 (13.2%). There were only two cases of early FGR (before 32 weeks); therefore, the study focused on late FGR. Our current FGR diagnostic criterion of EFW < 10th percentile was not associated significantly with composite ANO (relative risk (RR), 1.1 (95% CI, 0.6-1.8)), while the Delphi FGR criteria were (RR, 2.0 (95% CI, 1.2-3.3)). Our current definition of FGR showed higher discriminatory ability in the prediction of a SGA neonate (AUC, 0.69 (95% CI, 0.65-0.73)) than did the Delphi definition (AUC, 0.64 (95% CI, 0.60-0.67)) (P = 0.001). The AUCs of both definitions were poor for the prediction of composite ANO, despite slightly improved performance using the Delphi consensus definition of FGR (AUC, 0.53 (95% CI, 0.50-0.55)) compared with that of our current definition (AUC, 0.50 (95% CI, 0.48-0.53)) (P = 0.02). CONCLUSION: The newly postulated criteria for defining FGR based on a Delphi procedure detects fewer cases of neonatal SGA than does our current definition of EFW < 10th percentile, but is associated with a slight improvement in predicting ANO. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Risk factors for Cesarean delivery in pregnancy with small-for-gestational-age fetus undergoing induction of labor.

OBJECTIVES: To identify risk factors for Cesarean delivery and non-reassuring fetal heart tracing (NRFHT) in pregnancies with a small-for-gestational-age (SGA) fetus undergoing induction of labor and to design and validate a prediction model, combining antenatal and intrapartum variables known at the time of labor induction, to identify pregnancies at increased risk of Cesarean delivery. METHODS: This was a retrospective cohort study of non-anomalous, singleton gestations with a SGA fetus that underwent induction of labor, delivered in a single tertiary referral center between January 2011 and December 2016. SGA was defined as estimated fetal weight (EFW) < 10th percentile. The primary outcome was to identify risk factors associated with Cesarean delivery. The secondary outcome was to identify risk factors associated with NRFHT. Univariate and multivariate analyses were used to determine which clinical characteristics, available at the time of admission, had the strongest association with Cesarean delivery and NRFHT during labor induction. The predictive value of the final models was assessed by the area under the receiver-operating-characteristics curve (AUC). Sensitivity and specificity of the models were also assessed. Internal validation of the models was performed using 10 000 bootstrap replicates of the original cohort. The adequacy of the models was evaluated using the Hosmer-Lemeshow goodness-of-fit test. RESULTS: A total of 594 pregnancies were included. Cesarean delivery was performed in 243 (40.9%) pregnancies. Significant risk factors associated with Cesarean delivery, and included in the final model, were maternal age, gestational age at delivery and initial method of labor induction. The bootstrap estimate of the AUC of the final prediction model for Cesarean delivery was 0.82 (95% CI, 0.78-0.86). The model had sensitivity of 64.2%, specificity of 86.9%, positive likelihood ratio (LR) of 4.9 and negative LR of 0.41. The model had good fit (P = 0.617). NRFHT complicated 117 (19.7%) pregnancies. Significant risk factors for NRFHT included EFW < 5th percentile, abnormal umbilical artery Doppler studies (pulsatility index > 95th percentile or absent/reversed end-diastolic flow) and gestational age at delivery. The final prediction model for NRFHT had an AUC of 0.69 (95% CI, 0.63-0.75) and specificity of 97.0%. CONCLUSION: We identified several significant risk factors for Cesarean delivery and NRFHT among SGA pregnancies undergoing induction of labor. Clinicians may use these risk factors to guide patient counseling and to help anticipate the potential need for operative delivery. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Risk of miscarriage following amniocentesis or chorionic villus sampling: systematic review of literature and updated meta-analysis.

OBJECTIVE: To estimate the procedure-related risk of miscarriage after amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and an updated meta-analysis. METHODS: A search of MEDLINE, EMBASE and The Cochrane Library was carried out to identify studies reporting complications following CVS or amniocentesis. Eligible for inclusion were large controlled studies reporting data for pregnancy loss prior to 24 weeks' gestation. Study authors were contacted when required to identify additional necessary data. Data for cases that had an invasive procedure and controls were inputted into contingency tables and the risk of miscarriage was estimated for each study. Summary statistics based on a random-effects model were calculated after taking into account the weighting for each study included in the systematic review. Procedure-related risk of miscarriage was estimated as a weighted risk difference from the summary statistics for cases and controls. Subgroup analyses were performed according to the similarity in risk levels for chromosomal abnormality between the invasive-testing and control groups. Heterogeneity was assessed using the I2 statistic. Egger's bias was estimated to assess reporting bias in published studies. RESULTS: The electronic search yielded 2943 potential citations, from which 12 controlled studies for amniocentesis and seven for CVS were selected for inclusion in the systematic review. A total of 580 miscarriages occurred following 63 723 amniocentesis procedures, resulting in a weighted risk of pregnancy loss of 0.91% (95% CI, 0.73-1.09%). In the control group, there were 1726 miscarriages in 330 469 pregnancies with a loss rate of 0.58% (95% CI, 0.47-0.70%). The weighted procedure-related risk of miscarriage following amniocentesis was 0.30% (95% CI, 0.11-0.49%; I2 = 70.1%). A total of 163 miscarriages occurred following 13 011 CVS procedures, resulting in a risk of pregnancy loss of 1.39% (95% CI, 0.76-2.02%). In the control group, there were 1946 miscarriages in 232 680 pregnancies with a loss rate of 1.23% (95% CI, 0.86-1.59%). The weighted procedure-related risk of miscarriage following CVS was 0.20% (95% CI, -0.13 to 0.52%; I2 = 52.7%). However, when studies including only women with similar risk profiles for chromosomal abnormality in the intervention and control groups were considered, the procedure-related risk for amniocentesis was 0.12% (95% CI, -0.05 to 0.30%; I2 = 44.1%) and for CVS it was -0.11% (95% CI, -0.29 to 0.08%; I2 = 0%). CONCLUSIONS: The procedure-related risks of miscarriage following amniocentesis and CVS are lower than currently quoted to women. The risk appears to be negligible when these interventions were compared to control groups of the same risk profile. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Riesgo de aborto después de una amniocentesis o una biopsia de vellosidades coriónicas: revisión sistemática de bibliografía y metaanálisis actualizado OBJETIVO: Estimar el riesgo de aborto relacionado con el procedimiento de la amniocentesis o la biopsia de vellosidades coriónicas (BVC) mediante una revisión sistemática de bibliografía y un metaanálisis actualizado. MÉTODOS: Se realizó una búsqueda en MEDLINE, EMBASE y The Cochrane Library para identificar estudios que reportaron sobre complicaciones después de una BVC o amniocentesis. Se consideraron elegibles para su inclusión los estudios controlados de gran tamaño que reportaron datos sobre la pérdida del embarazo antes de las 24 semanas de gestación. Se estableció contacto con los autores de los estudios cuando fue necesario para identificar datos adicionales necesarios. Se introdujeron en tablas de contingencia los datos de los casos que se sometieron a un procedimiento invasivo y controles y se estimó el riesgo de aborto para cada estudio. Las estadísticas resumen basadas en un modelo de efectos aleatorios se calcularon después de tener en cuenta la ponderación para cada estudio incluido en la revisión sistemática. El riesgo de aborto relacionado con cada procedimiento se estimó como una diferencia de riesgo ponderada de las estadísticas resumen para los casos y controles. Los análisis de subgrupos se realizaron de acuerdo con la similitud en los niveles de riesgo de anomalías cromosómicas entre los grupos de prueba invasiva y de control. La heterogeneidad se evaluó mediante el test estadístico I2 . Se estimó el sesgo de Egger para evaluar el sesgo de información reportada en los estudios publicados. RESULTADOS: La búsqueda electrónica arrojó 2943 citas potenciales, de las cuales se seleccionaron para su inclusión en la revisión sistemática 12 estudios controlados para la amniocentesis y siete para la BVC. Después de los 63723 procedimientos de amniocentesis sucedieron un total de 580 abortos, lo que resultó en un riesgo ponderado de pérdida de embarazo del 0,91% (IC 95%, 0,73-1,09%). En el grupo de control hubo 1726 abortos en 330469 embarazos, con una tasa de pérdida del 0,58% (IC 95%, 0,47-0,70%). El riesgo ponderado de aborto relacionado con el procedimiento de amniocentesis fue del 0,30% (IC 95%, 0,11-0,49%; I2  = 70,1%). Después de 13011 procedimientos de BVC se produjeron un total de 163 abortos, lo que resultó en un riesgo de pérdida de embarazo del 1,39% (IC 95%, 0,76-2,02%). En el grupo de control hubo 1946 abortos en 232680 embarazos, lo que supuso una tasa de pérdida del 1,23% (IC 95%, 0,86-1,59%). El riesgo ponderado de aborto relacionado con el procedimiento de BVC fue de 0,20% (IC 95%, -0,13-0,52%; I2  = 52,7%). Sin embargo, cuando se consideraron los estudios que incluyeron sólo mujeres con perfiles de riesgo similares para la anomalía cromosómica en los grupos de intervención y control, el riesgo relacionado con el procedimiento de la amniocentesis fue de 0,12% (IC 95%, -0,05-0,30%; I2  = 44.1%) y para el MVC fue de -0,11% (IC 95%, -0,29-0,08%; I2  = 0%). CONCLUSIONES: Los riesgos de aborto relacionados con el procedimiento de la amniocentesis y la BVC son menores que los actualmente mencionados a las mujeres. El riesgo parece ser insignificante cuando estas intervenciones se compararon con grupos de control del mismo perfil de riesgo.

Systematic error and cognitive bias in obstetric ultrasound.

Linked Comment: Ultrasound Obstet Gynecol 2019; 53: 454-464.