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Outcomes of fetuses with small head circumference on second-trimester ultrasonography
Prenatal Diagnosis,
Deloison B et al. – A head circumference below the 5th centile at second–trimester scan is associated with various abnormalities, especially neurological disorders. The outcome was worse when the HC was smaller. An HC Z score below –2.5 was strongly associated with neurological and chromosomal abnormalities. Conversely, an HC Z score below –1.645 but above –2, excluding cases with prenatally diagnosed malformations, seems to be reassuring for favorable neonatal outcome.
Methods- Autors retrospectively analysed outcomes of 18377 women according to HC Z scores at second–trimester ultrasound examination between 2001 and 2008.
- They collected all major malformations, intrauterine deaths and other abnormal outcomes.
- Six hundred seventy–four fetuses (3.7%) had an HC below the 5th centile.
- Twenty–one major malformations were noted, consisting mainly of neurological abnormalities (3.1%).
- There were seven intra uterine fetal death (1.3%). Of all the fetuses, 26% were lost to follow–up.
- Outcome and neurological development was normal in 467 cases, based on neonatal examination and/or parent or general practitioner reports.
- Major abnormalities were noted in respectively 26.2%, 3.0% and 1.1% of fetuses with Z scores<–2.5, –2.5 to –2.0, and –2 to –1.645, compared with 0.3% of fetuses with normal HC (p<10–4).
