Objective: To review the evidence on the effect of mode of delivery on perinatal outcome of fetuses born before 32 weeks' gestation.Methods: MEDLINE, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), the ClinicalTrials.gov registry and gray literature sources were searched, starting from the year 2000 to reflect contemporary practice in perinatal care. Non‐randomized or randomized studies that included singleton fetuses without chromosomal abnormality or major congenital defect delivered vaginally or via Cesarean section were eligible for inclusion in the analysis. Primary outcomes were neonatal death, defined as death in the first 28 days of age, and survival to discharge. Secondary outcomes were other adverse perinatal events. The ROBINS‐I tool was used to assess the risk of bias. The overall quality of evidence for the outcomes was assessed according to GRADE. Summary odds ratios (ORs) with 95% CIs were calculated, and random‐effects models were used for data synthesis. Subgroup analysis was performed for delivery before 28 weeks, delivery between 28 and 32 weeks and according to fetal presentation at delivery.Results: A total of 27 retrospective studies (22 887 neonates) were included in the systematic review and meta‐analysis, all of which reported on singleton pregnancies. Among cases born before 28 weeks, vaginal delivery significantly increased the risk of neonatal death of fetuses with any type of presentation (n = 1496) (OR 1.87 (95% CI, 1.05–3.35); I² = 65%, very low quality of evidence) and of fetuses with breech presentation (n = 733) (OR 3.55 (95% CI, 2.42–5.21); I² = 21%, moderate quality of evidence). The odds of survival to discharge were significantly decreased among fetuses with breech presentation delivered before 28 weeks (n = 646) (OR 0.36 (95% CI, 0.24–0.54); I² = 21%, low quality of evidence). Among breech fetuses born between 28 and 32 weeks, vaginal delivery increased the odds of perinatal death (intrapartum and neonatal) (n = 1581) (OR 3.06 (95% CI, 1.47–6.35); I² = 0%, high quality of evidence). In non‐cephalic fetuses born between 24 and 32 weeks, vaginal delivery decreased the odds of survival to discharge (n = 1030) (OR 0.28 (95% CI, 0.19–0.40); I² = 0%, moderate quality of evidence). No significant effect on mortality of mode of delivery was observed in cephalic fetuses at any gestational age.Conclusions: This systematic review and meta‐analysis suggests that vaginal delivery in severe preterm birth is associated with an increased risk of neonatal and perinatal death in breech fetuses, while no significant association was observed for cephalic fetuses. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Objective: To critically review the literature and synthesize evidence on the incremental yield of prenatal exome sequencing (PES) in fetuses with an apparently normal phenotype with a normal G‐banded karyotype or chromosomal microarray (CMA).Methods: This systematic review and meta‐analysis was conducted using a predetermined protocol and registered with PROSPERO (ID: CRD42024593349). We included observational cohort studies reporting on the incremental yield of PES in fetuses with an apparently normal phenotype and a previously normal G‐banded karyotype/CMA. The risk of bias of the included studies was assessed using the Newcastle–Ottawa Scale. The pooled proportion of events was calculated using generalized linear mixed models, using the metaprop function in R version 2.15.1.Results: Four studies (1916 fetuses) were included in this systematic review and meta‐analysis, of which 32 cases had a pathogenic or likely pathogenic variant. The pooled incremental yield of PES in fetuses with an apparently normal phenotype was 1.6% (95% CI, 1.0–2.6%); the majority of variants were de novo within genes associated with autosomal dominant inherited conditions (pooled incremental yield, 0.9% (95% CI, 0.5–1.7%)). Based on the expected severity of the associated disease, the pooled incremental yield was 0.5% (95% CI, 0.1–1.5%) for severe disease and 0.5% (95% CI, 0.2–1.5%) for moderate disease. There were insufficient data to conduct the predefined secondary analyses according to normality of phenotype at birth, variants of uncertain significance and expected age of disease onset.Conclusion: Pooling data from four studies, we found that 1.6% of phenotypically normal fetuses with a normal G‐banded karyotype or CMA may have a pathogenic or likely pathogenic variant identified on PES, most of which occur de novo. The likelihood of a variant being associated with severe disease in such fetuses is 0.5%. However, more research is needed regarding the development of a universal classification of disease severity and the utilization of this evidence in clinical practice. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Background: The examination of the uterine arteries using Doppler in the first trimester of pregnancy serves as a valuable tool for evaluating the uteroplacental circulation. Diabetes mellitus is associated with altered placental implantation and pregnancy-related pathologies, such as preeclampsia. The aim of this study was to compare the uterine arteries’ pulsatility indices (UtA PI) in women with diabetes mellitus type 1 (DM1), diabetes mellitus type 2 (DM2), gestational diabetes mellitus (GDM), and uncomplicated pregnancies. Methods: This was a retrospective case–control trial including pregnant women with DM1, DM2, GDM, and uncomplicated pregnancies, presenting for first-trimester ultrasound screening in two tertiary university hospitals between 2013 and 2023. The first-trimester UtA pulsatility index (PI), expressed in multiples of medians (MoMs), was compared between the four groups. Results: Out of 15,638 pregnant women, 58 women with DM1, 67 women with DM2, 65 women with GDM, and 65 women with uncomplicated pregnancies were included. The mean UtA PI were 1.00 ± 0.26 MoMs, 1.04 ± 0.32 MoMs, 1.02 ± 0.31 MoMs, and 1.08 ± 0.33 MoMs in pregnant women with DM1, DM2, GDM, and uncomplicated pregnancies, respectively (p > 0.05). Conclusions: Potential alterations in the implantation of the placenta in pregnant women with diabetes were not displayed in the first-trimester pulsatility indices of the uterine arteries, as there were no changes between the groups.

Objectives: To examine the contribution of maternal demographic characteristics and elements of medical history to the prediction of prolonged (> 2 days) neonatal intensive care unit (NICU) admission for high‐dependency or intensive care, and to investigate the added value to such prediction of the findings from the 36‐week ultrasound scan and data from labor and delivery. Methods: We included 107 762 women with a singleton pregnancy who had undergone a routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation. Assessment included medical history, estimated fetal weight (EFW), and Doppler measurements of uterine artery (UtA) pulsatility index (PI), umbilical artery (UA) PI and fetal middle cerebral artery (MCA) PI. Multivariable logistic regression was used to evaluate the independent contributions to prolonged NICU admission of maternal factors (demographic and pregnancy characteristics), findings from the 36‐week scan, and data from labor and delivery. Detection rates (DRs) and areas under the receiver‐operating‐characteristics curve (AUCs) for prolonged NICU admission were compared. Results: Overall, 946 (0.88%) neonates required prolonged NICU admission. The maternal factors that significantly contributed to prediction of prolonged NICU admission were body mass index, social deprivation, conception via in‐vitro fertilization, chronic hypertension, Type‐1 diabetes mellitus, pre‐eclampsia and gestational diabetes mellitus. Screening by maternal factors provided a DR of 20.7% at a false‐positive rate (FPR) of 10% (AUC, 0.606 (95% CI, 0.587–0.625)). Significant predictors from the 36‐week scan included deepest vertical pocket of amniotic fluid < 2 cm and ≥ 8 cm, UA‐PI >95 ^th percentile and MCA‐PI < 5 ^th percentile. Screening by a combination of maternal factors and 36‐week scan findings improved the DR at a 10% FPR to 27.5% (AUC, 0.637 (95% CI, 0.618–0.656)). When maternal factors, 36‐week scan findings, and data from labor and delivery (lower gestational age at delivery, delivery by Cesarean section and birth weight < 10 ^th and > 90 ^th percentile) were included in the model, the DR at a 10% FPR improved to 39.1% (AUC, 0.709 (95% CI, 0.690–0.728)). When this combined model was restricted to prediction of prolonged NICU admission for indications that excluded those affected by intrapartum events, the DR at a 10% FPR was 57.2% (AUC, 0.790 (95% CI, 0.764–0.815)). Conclusions: Maternal factors (particularly social deprivation), 36‐week scan findings, and data from labor and delivery each make an independent contribution to the risk of prolonged NICU admission at term. Nevertheless, more than 40% of these admissions are not predictable prior to labor and birth. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.