Adverse outcome following selective termination of presenting twin vs non-presenting twin.

OBJECTIVE: Data are lacking on the impact on pregnancy outcome of the position of the abnormal fetus in a discordant twin pregnancy undergoing selective termination (ST). Tissue maceration post ST of the presenting twin may lead to early rupture of membranes, amnionitis and preterm labor. The aim of this study was to evaluate pregnancy complications and outcome following ST of the presenting vs non-presenting twin. METHODS: This was a multicenter retrospective cohort study of dichorionic diamniotic twin pregnancies that underwent ST due to a discordant fetal anomaly (structural or genetic) between 2007 and 2021. The study population was divided into two groups according to the position of the reduced twin (presenting or non-presenting) and outcomes were studied accordingly. The primary outcome was a composite of early complications following ST, including infection, preterm prelabor rupture of membranes and pregnancy loss. RESULTS: A total of 190 dichorionic twin pregnancies were included, of which 73 underwent ST of the presenting twin and 117 of the non-presenting twin. The groups did not differ in either baseline demographic characteristics or mean gestational age at the time of the procedure. ST of the presenting twin resulted in a significantly higher rate of early complications compared with the non-presenting twin (19.2% vs 7.7%; P = 0.018). Moreover, the rates of preterm delivery (75.3% vs 37.6%; P < 0.001) and neonatal intensive care unit admission (45.3% vs 17.1%; P < 0.001) were higher, and birth weight was lower (P < 0.001), in those pregnancies in which the presenting twin was reduced. CONCLUSIONS: ST of the presenting twin resulted in a higher rate of adverse pregnancy outcome compared with that of the non-presenting twin. These findings should be acknowledged during patient counseling and, if legislation permits, taken into consideration when planning ST. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Doppler evaluation of normal and abnormal placenta.

Doppler techniques are needed for the evaluation of the intraplacental circulation and can be of great value in the diagnosis of placental anomalies. Highly sensitive Doppler techniques can differentiate between the maternal (spiral arteries) and fetal (intraplacental branches of the umbilical artery) components of the placental circulation and assist in the evaluation of the placental functional units. A reduced number of placental functional units can be associated with obstetric complications, such as fetal growth restriction. Doppler techniques can also provide information on decidual vessels and blood movement. Abnormal decidual circulation increases the risk of placenta accreta. Doppler evaluation of the placenta greatly contributes to the diagnosis and clinical management of placenta accreta, vasa previa, placental infarcts, placental infarction hematoma, maternal floor infarction, massive perivillous fibrin deposition and placental tumors. However, it has a limited role in the diagnosis and clinical management of placental abruption, placental hematomas, placental mesenchymal dysplasia and mapping of placental anastomoses in monochorionic twin pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prediction of adverse perinatal outcome by fetal biometry: comparison of customized and population-based standards.

OBJECTIVE: To compare the predictive performance of estimated fetal weight (EFW) percentiles, according to eight growth standards, to detect fetuses at risk for adverse perinatal outcome. METHODS: This was a retrospective cohort study of 3437 African-American women. Population-based (Hadlock, INTERGROWTH-21st , World Health Organization (WHO), Fetal Medicine Foundation (FMF)), ethnicity-specific (Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)), customized (Gestation-Related Optimal Weight (GROW)) and African-American customized (Perinatology Research Branch (PRB)/NICHD) growth standards were used to calculate EFW percentiles from the last available scan prior to delivery. Prediction performance indices and relative risk (RR) were calculated for EFW < 10th and > 90th percentiles, according to each standard, for individual and composite adverse perinatal outcomes. Sensitivity at a fixed (10%) false-positive rate (FPR) and partial (FPR < 10%) and full areas under the receiver-operating-characteristics curves (AUC) were compared between the standards. RESULTS: Ten percent (341/3437) of neonates were classified as small-for-gestational age (SGA) at birth, and of these 16.4% (56/341) had at least one adverse perinatal outcome. SGA neonates had a 1.5-fold increased risk of any adverse perinatal outcome (P < 0.05). The screen-positive rate of EFW < 10th percentile varied from 6.8% (NICHD) to 24.4% (FMF). EFW < 10th percentile, according to all standards, was associated with an increased risk for each of the adverse perinatal outcomes considered (P < 0.05 for all). The highest RRs associated with EFW < 10th percentile for each adverse outcome were 5.1 (95% CI, 2.1-12.3) for perinatal mortality (WHO); 5.0 (95% CI, 3.2-7.8) for perinatal hypoglycemia (NICHD); 3.4 (95% CI, 2.4-4.7) for mechanical ventilation (NICHD); 2.9 (95% CI, 1.8-4.6) for 5-min Apgar score < 7 (GROW); 2.7 (95% CI, 2.0-3.6) for neonatal intensive care unit (NICU) admission (NICHD); and 2.5 (95% CI, 1.9-3.1) for composite adverse perinatal outcome (NICHD). Although the RR CIs overlapped among all standards for each individual outcome, the RR of composite adverse perinatal outcome in pregnancies with EFW < 10th percentile was higher according to the NICHD (2.46; 95% CI, 1.9-3.1) than the FMF (1.47; 95% CI, 1.2-1.8) standard. The sensitivity for composite adverse perinatal outcome varied substantially between standards, ranging from 15% for NICHD to 32% for FMF, due mostly to differences in FPR; this variation subsided when the FPR was set to the same value (10%). Analysis of AUC revealed significantly better performance for the prediction of perinatal mortality by the PRB/NICHD standard (AUC = 0.70) compared with the Hadlock (AUC = 0.66) and FMF (AUC = 0.64) standards. Evaluation of partial AUC (FPR < 10%) demonstrated that the INTERGROWTH-21st standard performed better than the Hadlock standard for the prediction of NICU admission and mechanical ventilation (P < 0.05 for both). Although fetuses with EFW > 90th percentile were also at risk for any adverse perinatal outcome according to the INTERGROWTH-21st (RR = 1.4; 95% CI, 1.0-1.9) and Hadlock (RR = 1.7; 95% CI, 1.1-2.6) standards, many times fewer cases (2-5-fold lower sensitivity) were detected by using EFW > 90th percentile, rather than EFW < 10th percentile, in screening by these standards. CONCLUSIONS: Fetuses with EFW < 10th percentile or EFW > 90th percentile were at increased risk of adverse perinatal outcomes according to all or some of the eight growth standards, respectively. The RR of a composite adverse perinatal outcome in pregnancies with EFW < 10th percentile was higher for the most-stringent (NICHD) compared with the least-stringent (FMF) standard. The results of the complementary analysis of AUC suggest slightly improved detection of adverse perinatal outcome by more recent population-based (INTERGROWTH-21st ) and customized (PRB/NICHD) standards compared with the Hadlock and FMF standards. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Sliding sign in third-trimester sonographic evaluation of intra-abdominal adhesions in women undergoing repeat Cesarean section: a novel technique.

OBJECTIVE: Intra-abdominal adhesions are associated with an increased risk of complications during repeat Cesarean section (CS), such as bladder and bowel injury, hemorrhage, infection and hysterectomy. We present a simple sonographic marker, the 'sliding sign' of the uterus, for the prediction of intra-abdominal adhesions in the third trimester of pregnancy in women undergoing repeat CS. METHODS: This was a prospective observational study of pregnant women with a history of at least one Cesarean delivery evaluated by transabdominal ultrasound during the third trimester of an ongoing pregnancy. In order to diagnose intra-abdominal adhesions, we assessed a sonographic sign, the sliding of the uterus under the inner part of the fascia of the abdominal muscles during deep breathing. Women were considered to be at high risk for severe adhesions if uterine sliding was absent and at low risk in the presence of obvious or moderate uterine sliding. A comparison between sonographic findings and intra-abdominal adhesions observed during surgery was performed. RESULTS: Of the 63 patients with one or more previous CS examined, 59 completed the study and underwent CS at our institution. In 16 of the 19 cases assigned to the high-risk group for severe adhesions due to absence of sliding of the uterus, the suspicion was confirmed at surgery. The prediction of low risk for adhesions was confirmed in 35 out of 40 patients. The sensitivity and specificity of the sliding sign in predicting presence of intra-abdominal adhesions in women undergoing repeat CS were 76.2% and 92.1%, respectively. Inter- and intraobserver correlation using Cohen's kappa coefficient were 0.52 and 0.77, respectively. CONCLUSION: Our data show that a simple sonographic sign might be able to discriminate between high and low risk for intra-abdominal adhesions in patients with a history of Cesarean delivery. This technique may aid clinical decisions in patients undergoing repeat CS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.