Monoamniotic Twins: A Case Series

Monoamniotic twinning is a rare event associated with a high perinatal morbidity and mortality. In this article, six pairs of monoamniotic twins diagnosed prenatally during 2001-2003 were evaluated. The management protocol included documentation of chorionicity and amnionicity by early ultrasonographic examination, 2-4 weekly serial ultrasound surveillance, antepartum fetal heart rate monitoring initiated at 28 weeks of gestation and a non-interventional approach beyond 32 weeks. In 5 cases, the detection of monoamnionicity was made during the first trimester. Cord entanglement was found in four cases. In only one case (acardiac twin) was there discordance for structural abnormality. In all cases, the pregnancy continued beyond 20 weeks, and with a non-interventional management policy, a live birth rate of 80% beyond 24 weeks was achieved. We believe that, at any given gestation, if prematurity complications are likely to outweigh the risk of an uncertain IUFD, a non-interventional management may be a reasonable option.