Congenital malformations at birth--a prospective study from south India.

Congenital malformations were studied prospectively from September 1989 to December 1992 covering 12,797 consecutive deliveries. The overall incidence of malformations was 3.7% and it was 3.2% among live births and 15.7% among still births. Three hundred and ninety seven birth defects were observed among 308 live births and 72 among 45 still births. The incidence of malformation was significantly higher among male babies (p < 0.001), still births (p < 0.001), low birth weights (p < 0.001) and preterm babies (p < 0.001). Consanguinity among parents of malformed babies was more common (p < 0.001). Musculo-skeletal malformations were the commonest (9.69 per 1000) followed by cutaneous (6.33 per 1000), genitourinary (5.47 per 1000), gastrointestinal (5.47 per 1000), central nervous system (3.99 per 1000) and cardiac anomalies (2.03 per 1000). Musculoskeletal, cutaneous and genitourinary malformations were common among live born babies while central nervous system and gastrointestinal defects were common among still born babies. Antenatal infections and ingestion of drugs were not found to be significant factors in the causation of birth defects.