Characteristics of fetuses evaluated due to suspected anencephaly: a population-based cohort study in southern Brazil.

CONTEXT AND OBJECTIVE: Anencephaly is considered to be the most common type of neural tube defect. Our aim was to assess the clinical and gestational features of a cohort of fetuses with suspected anencephaly.

DESIGN AND SETTING: Population-based retrospective cohort study in a referral hospital in southern Brazil.

METHODS: The sample consisted of fetuses referred due to suspected anencephaly, to the Fetal Medicine Service of Hospital Materno Infantil Presidente Vargas, between January 2005 and September 2013. Clinical, radiological, pathological and survival data were gathered.

RESULTS: Our sample was composed of 29 fetuses. The diagnosis of suspected anencephaly was made on average at 21.3 weeks of gestation. Seven fetuses had malformations that affected other organs, and these included oral clefts (n = 4) and congenital heart defects (n = 2). In 16 cases, there was termination of pregnancy (n = 12) or intrauterine death (n = 4). Regarding those who were born alive (n = 13), all of them died in the first week of life. After postnatal evaluation, the diagnosis of anencephaly was confirmed in 22 cases (75.9%). Other conditions included amniotic band disruption complex (6.9%), microhydranencephaly (6.9%), merocrania (3.4%) and holoprosencephaly (3.4%).

CONCLUSIONS: Different conditions involving the cranial vault may be confused with anencephaly, as seen in our sample. However, these conditions also seem to have a poor prognosis. It seems that folic acid supplementation is not being properly performed.