Predicting Adverse Outcomes in Monochorionic-Diamniotic Twins: The Role of Intertwin Discrepancy in Middle Cerebral Artery Doppler Measurements and the Cerebroplacental Ratio

Update on Management and Outcomes of Monochorionic Twin Pregnancies

The management of multiple pregnancies complicated by monochorionicity continues to evolve as new investigations support a change in clinical practice to optimize outcomes. Monochorionic twins are at risk of unique conditions such as monoamnionicity, conjoined twinning, twin reversed arterial perfusion sequence, twin-twin transfusion syndrome, twin anemia-polycythemia sequence, unequal placental sharing with discordant twin growth or selective fetal growth restriction, and single-twin death that puts co-twins at risk of death or neurologic injury attributable to the shared placenta. Contemporary practice guidelines recommend serial ultrasonographic surveillance of monochorionic pregnancies to increase the early detection of problems and timely management decisions that may include increased surveillance, selective reduction or pregnancy termination, referral for in utero treatment, or earlier delivery than initially planned. Improvements in prenatal diagnosis and antenatal testing and advances in fetal therapy have contributed to more favorable outcomes in these complicated monochorionic gestations.

Value of cerebroplacental ratio in predicting adverse perinatal outcome in uncomplicated twin pregnancies: a retrospective study

To evaluate the performance of the cerebroplacental ratio (CPR) in predicting operative delivery for intrapartum fetal compromise (OD for IFC) and adverse perinatal outcomes in uncomplicated twin pregnancies with attempted vaginal delivery.This was a retrospective cohort study of 72 twin pregnancies in a single tertiary referral center between January 2018 and August 2024. All MCDA and DCDA twin pregnancies with an attempted vaginal delivery after 34+0 weeks were screened for eligibility and those without further risk factors were included in the study. Outcome parameters were OD for IFC and a composite of adverse perinatal outcomes (CAPO) including OD for IFC, 5-minute Apgar score <7, umbilical artery pH <7.10, or admission to the neonatal intensive care unit (NICU). The predictive performance of CPR was evaluated using ROC analyses and multivariable logistic regression.16 MCDA and 56 DCDA pregnancies met the inclusion criteria. CAPO of at least one of the twins occurred in 27 (37.5%) of the cases. ROC analyses showed that low CPR MoM of neither the presenting twin nor the second twin predicted CAPO. Similarly, the prediction of the need for OD for IFC of twin 2 was not possible using low CPR MoM as the predicting variable. However, logistic regression analyses showed that nulliparity and twin-to-twin delivery time interval were independently associated with CAPO.Low CPR MoM was not predictive for CAPO or OD for IFC in uncomplicated twin pregnancies after 34 weeks of gestation. However, nulliparity and twin-to-twin delivery time interval were independently associated with CAPO.

Doppler Indices of the Uterine, Umbilical and Fetal Middle Cerebral Artery in Diabetic versus Non-Diabetic Pregnancy: Systematic Review and Meta-Analysis

Background and Objectives: The aim of this study was to assess the differences in Doppler indices of the uterine (Ut), umbilical (UA), and middle cerebral artery (MCA) in diabetic versus non-diabetic pregnancies by conducting a comprehensive systematic review of the literature with a meta-analysis. Materials and Methods: PubMed, Web of Science, and SCOPUS were searched for studies that measured the pulsatility index (PI), resistance index (RI), and systolic/diastolic ratio index (S/D ratio) of the umbilical artery, middle cerebral artery, and uterine artery in diabetic versus non-diabetic pregnancies. Two reviewers independently evaluated the eligibility of studies, abstracted data, and performed quality assessments according to standardized protocols. The standardized mean difference (SMD) was used as a measure of effect size. Heterogeneity was assessed using the I2 statistic. Publication bias was evaluated by means of funnel plots. Results: A total of 62 publications were included in the qualitative and 43 in quantitative analysis. The UA-RI, UtA-PI, and UtA-S/D ratios were increased in diabetic compared with non-diabetic pregnancies. Subgroup analysis showed that levels of UtA-PI were significantly higher during the third, but not during the first trimester of pregnancy in diabetic versus non-diabetic pregnancies. No differences were found for the UA-PI, UA-S/D ratio, MCA-PI, MCA-RI, MCA-S/D ratio, or UtA-RI between diabetic and non-diabetic pregnancies. Conclusions: This meta-analysis revealed the presence of hemodynamic changes in uterine and umbilical arteries, but not in the middle cerebral artery in pregnancies complicated by diabetes.