Risk factors for small for gestational age births in Ahmedabad, India.

Intra-uterine growth retardation is an important public health problem in many developing countries. The authors conducted a case-control study of low birth weight (LBW) in three teaching hospitals and a population survey in Ahmedabad city, India during 1987-1988. To identify and quantify risk factors for small for gestational age births, we divided the low birth weight and control infants into small for gestational age (SGA, n = 617) and appropriate for gestational age (AGA, n = 1851) using an Indian birth weight by gestational age standard. Logistic regression was used to estimate adjusted odds ratios for important risk factors. Prevalence of risk factors was estimated from a community sample survey of mothers (n = 1102) who had delivered in the past year. Attributable risks were calculated from odds ratios and prevalence data. The most important risk factors for SGA was poor maternal nutritional status (weight < 51 kg) with an attributable risk of 42 per cent. Other significant risk factors were anaemia, primiparity, poor obstetric history, lack of antenatal care and hypertension during pregnancy, and birth defects, each of which contributed only moderately to the attributable risk. The analysis indicates that improvement of maternal nutrition and antenatal care might prevent a substantial portion of SGA births in this and similar populations.