Objective: To investigate the patterns and associated malformations in neural tube defects (NTDs) cases.
Methods: From 1987 to 1995, hospital-based cluster sampling method was adopted for collecting data. During that period all live or still births with 28 weeks of gestation or more were assessed within 7 days after delivery.
Results: Three thousand seven hundred and ninety eight syndromic NTDs were identified, among which anencephaly, spina bifida and encephalocele were 997, 2394 and 407 respectively. 51.3% associated abnormalities of NTDs appeared in muscle and skeletal system, 19.6% in face, ear and neck, and 9.3% in urinary-genital system. Congenital talipes equinovarus, cleft lip with cleft palate, gastroschisis, talipes valgus, undescended testicle were frequently combined with NTDs. The most frequent association in schisis type of NTDs was NTDs accompanied by cleft lip with or without cleft palate (67.5%), followed by anencephaly with cleft palate (8.3%) and anencephaly with omphalocele (6.6%). Of all syndromic NTDs, the rate of low birth weight was 36.9%, of perinatal mortality was 71.2% and the ratio 33.1% patients were diagnosed prenatally.
Conclusions: Approximately one third of NTDs may be associated with other system's malformation. Syndromic NTDs has a high perinatal mortality rate and a poor prognosis.