Discordance for fetal anencephaly in a dichorionic twin pregnancy: A case report

Anencephaly is a frequent and easily diagnosed condition affecting twin pregnancies with higher incidence than singletons. Discordance for anencephaly in twins raises management dilemmas about the best approach to the situation. The authors report a successful case of a 33 years old woman who had a dichorionic twin pregnancy resulting from ICSI, with discordance for anencephaly. Diagnosis was performed at 13 weeks during first trimester ultrasound screening. A selective feticide with intrathoracic injection of KCl at 13 + 2 weeks was performed with no complications. The normal fetus proceeded with an uneventful pregnancy with spontaneous vaginal delivery at 40 weeks, weighting 3110 g. Management of twin pregnancies discordant for fetal anencephaly is far from being consensual. Two options are considered: selective feticide or expectant management, with serial ultrasound surveillance. In the latter option, amniodrainage or selective feticide may become options if polyhydramnios develops later in pregnancy. Therapeutic strategy requires an individual approach considering chorionicity, gestational age and all the risks of miscarriage, preterm labor and fetal demise to which these pregnancies are particularly exposed.