Prenatal diagnosis and outcome of fetuses with isolated agen
The objective was to evaluate the postnatal outcome of children with a prenatal diagnosis of apparently isolated agenesis of the septum pellucidum agenesis (ASP).

A retrospective cohort study of cases of prenatally diagnosed ASP followed in 2 tertiary centers and a meta-analysis of existing studies was carried out. Only cases with apparently isolated ASP at the antenatal ultrasound and/or MRI and available postnatal follow-up were considered eligible for this study.

The following outcomes were analyzed: incidence of chromosomal anomalies, the agreement between antenatal and postnatal findings, the overall incidence of SOD (septo-optic dysplasia), and the incidence of major neurological disability (motor, language of behavioral disease) in non-SOD children. The incidence of SOD in those cases with apparently normal visual pathways at antenatal imaging was also evaluated.

Fifteen cases of isolated ASP with a median postnatal follow-up of 36 months were selected from the two Centres. Six studies met the inclusion criteria for the systematic review and a total of 79 cases were eligible for the analysis, including our series.

- Genetic tests were antenatally carried out in 30 fetuses and turned out to be abnormal in 2 of them.

- Additional or discordant imaging findings were postnatally noted in 9/70 patients; Among the 79 neonates with available follow-up, SOD was postnatally diagnosed in 14 cases.

- In 60 cases Optic nerves or optic tracts were considered to be normal at antenatal imaging; among them, a diagnosis of SOD was carried out in 6 cases.

- Among the 46 infants with an available neurological follow-up that were not affected by SOD, a major neurological disability was diagnosed in 3.

In the vast majority of cases with apparently isolated ASP, the prognosis is favorable. However, additional anomalies are detected after birth in about 10% of these cases and have a negative impact on the clinical outcome. The antenatal visualization of the optic tract does not rule out SOD.

Ultrasound in Obstetrics & Gynecology