Outcomes of dichorionic triplet pregnancies

Abstract

Objective: The objective of this study was to describe outcomes in a series of dichorionic triplet pregnancies.

Study design: All triplet pregnancies evaluated in our obstetric sonography unit from 1993 to 2000 were identified. Those containing a monochorionic twin pair were included. Prenatal and neonatal records were reviewed. Statistical comparison was performed by using Wilcoxon matched-pairs signed-ranked sum test.

Results: Seventeen cases met inclusion criteria. Two pregnancies (11.8%) were delivered spontaneously before viability, at 22 and 21 weeks. Twin-twin transfusion syndrome was diagnosed in the second trimester in the monochorionic pair in 3 pregnancies (17.6%). In the remaining 12 pregnancies, mean gestational age at delivery was 33.5 +/- 2.3 weeks. The median birth weight of 23 neonates from individual monochorionic twin pairs was 1810 g (interquartile range, 1540-2180 g), which was significantly lower than the median birth weight of 12 triplets supplied by a separate placenta, 2125 g (interquartile range, 1762-2390 g) (P =.01).

Conclusion: Twin-twin transfusion syndrome or spontaneous loss before viability complicated approximately 30% of dichorionic triplet pregnancies. Lower birth weights were noted in triplets from monochorionic twin pairs.