Maternal early second trimester pregnancy weight in relation to birth outcome among Bengalee Hindus of Kolkata, India.

Objective: The study examined to what degree maternal early second trimester pregnancy weight is useful and efficient in predicting birth outcome of Bengalee women.

Subjects And Methods: The cross-sectional retrospective study was conducted in a government general hospital in South Kolkata, India. This hospital serves the needs of people belonging to lower and lower middle class socio-economic groups. Data were collected by one-to-one interview for confirmation of age, history of last menstrual period (LMP) including medical disorders. Mother's weight was recorded at 14-18 weeks of pregnancy from the history of LMP. Birth weight was measured within 24h of delivery and gestational age was assessed by Ballard's method using newborn physical and neurological maturity scoring. Of the 331 Bengalees, 295 mother-baby pairs met the recruitment criteria and were included in this study.

Result: Mean +/- SD maternal early second trimester pregnancy weight and birth weight were 45.9+/-7.0kg and 2612+/-371g, respectively. The difference in mean weight (3.74kg) between mothers who delivered low birth weight (LBW) and normal birth weight (NBW) babies was statistically significant (t = 4.497, p < 0.001). Overall, the prevalence of LBW was nearly 34%. A higher incidence of LBW and lower mean birth weight was observed in first quartile or low weight (< or =40 kg) mothers. The rate of LBW decreased (chi2 =14.47, p<0.01) and mean birth weight increased significantly with increasing maternal weight (F=9.218, p<0.001). Risk ratio (RR) for LBW, intrauterine growth retardation (IUGR) and preterm birth in low weight (first quartile or <40.0 kg) mothers were 2.72 (95% confidence interval (CI): 1.45-5.10), 3.54 (95% CI: 1.17-10.74) and 1.97 (95% CI: 0.56-6.90), respectively, compared with heavier (>50.0kg) mothers. Finally, the present data showed that the maternal weight of <46.0 kg is the best cut-off for detecting LBW with 66% sensitivity and 75% negative predictive power.

Conclusion: The findings suggest a positive association between maternal early second trimester pregnancy weight and birth outcome. The present study provided an efficient cut-off point for detecting LBW. Antenatal caregivers in health institutions and community health workers in the field can use this cut-off value for screening pregnant women at early second trimester.