Dichorionic twin pregnancy discordant for anencephaly: two cases with different management

Prevalence ofanencephaly in dichorionic twins is higher than in singleton pregnancies. The authors report two cases with two different management strategies.

Spontaneous dichorionic diamniotic twin pregnancy with the second twin diagnosed with anencephaly at 12 weeks gestation. Selective feticide was performed at the age of 13.2 weeks. Vaginal delivery occurred at 39 weeks, and birth weight was 2,850 g.

Dichorionic diamniotic twin pregnancy discordant for anencephaly in the second twin was diagnosed at 13 weeks gestation. An expectant management was decided. Preterm delivery occurred at 35 weeks due to hydramnios of the affected fetus, delivering a healthy newborn weighing 2,300 g and an anencephalic neonate who died immediately after delivery.

Anencephaly should be diagnosed as soon as possible, idealistically at 11-13+6 weeks ultrasound (US) scan, in order to offer the most appropriate counselling to the parents, ranging from selective feticide or expectant management. This short series suggests that selective early feticide may increase gestational age and birth weight.