Monoamniotic twins discordant for anencephaly managed conservatively with good outcomes: two case reports and a review of the literature.

Monoamniotic twin pregnancy discordant for anencephaly (MATDA) is a rare occurrence with only seven prior reported cases. Selective termination has been advocated in managing discordant monoamniotic twins. We report two cases managed expectantly with good outcomes and review other previously reported cases. The first case was a primigravid woman diagnosed with MATDA at 18 weeks. She was managed expectantly until 32 + 5 weeks when a Cesarean section was performed for preterm labor. The surviving female infant weighed 1610 g. The second case was a multigravid woman who was diagnosed with MATDA at 17 + 5 weeks and was managed as an outpatient. An emergency Cesarean section was performed at 31 weeks for non-reassuring monitoring and the surviving male infant weighed 1790 g. In both cases, the survivors were discharged home in good condition. A review of these two cases and those in the literature suggests that expectant management should be considered among management options for this rare condition. Copyright 2005 ISUOG. Published by John Wiley & Sons, Ltd.