The cerebroplacental Doppler ratio and neonatal outcome in diamnionic monochorionic and dichorionic twins

Abstract

Objective: Neonatal outcome in twins was studied in relation to the cerebroplacental ratio (CPR). Methods: Seventy-five infants from twin pregnancies with fetal Doppler data obtained within 3 weeks of delivery were candidates for study (23 infants from diamnionic monochorionic and 52 infants from diamnionic dichorionic twin pregnancies). Multivariate regression analyses were expanded to include 114 twin infants (34 diamnionic monochorionic and 80 diamnionic dichorionic twins). Patients with twin transfusion syndrome were excluded from analysis in the monochorionic group. Targeted ultrasound examination with biometry was performed, and Doppler resistance index (RI) of the umbilical artery (UA) and the middle cerebral artery (MCA) were obtained, and the CPR, a measure of blood flow redistribution, was calculated. Outcome variables included major complications, growth restriction, days of ventilator and oxygen use, days in the neonatal intensive care unit and length of stay. Results: The CPR was correlated more highly with adverse outcomes such as birth weight, special-care nursery days and length of stay than were the UA RI or the MCA RI. The CPR was significantly lower in monochorionic compared with dichorionic twins (1.12 vs. 1.27, p = 0.01). Multivariate regression analyses conducted separately on each twin group also demonstrated that CPR was superior to UA RI and MCA RI in predicting length of stay and restricted growth. Among the Doppler variables, the CPR showed the highest sensitivity for growth restriction (67%). Conclusion: In twins, CPR was superior to UA RI and MCA RI in predicting adverse neonatal events.