Birthweight Data Of Live-Born Twins In Benin City, Nigeria
Background: Twin gestation is known to have a negative influence on birth weight. The mean birth weight of a population changes with time, making its periodic determination necessary. Objective: To determine the mean birth weight of twins in Benin City and examine some factors that may influence it. Methods: The birth weights and sexes of 104 live-born twin pairs delivered over a four-year period in a Nigerian mission hospital were prospectively recorded according to the month and year of delivery and were analyzed. The mean birth weights of twins born during the wet season were compared with those of their counterparts born during the dry season. Results: Combining both sexes, the overall mean birth weight (standard deviation, SD) of twins was 2392(560)g (95% confidence interval, CI = 2316 – 2468). Comparing mean birth weights (SD) of male and female twins it were 2467 (518)g (95% CI = 2367 – 2567) versus 2185 (630)g (95% CI = 2064 – 2306) P<0.01. The mean birth weights (SD) for male twin infants were 2604 (598)g (95% CI= 2437 – 2771) and 2265 (618)g (95% CI = 2081 – 2435) in wet and dry seasons respectively P < 0.02; while for their female counterparts it were 2378 (602)g (95% CI = 2226 – 2530) and 2251 (638)g (95% CI = 2065 – 2437) in wet and dry seasons respectively p > 0.05. Combining both sexes, the mean birth weights (SD) were 2480 (587)g (95% CI = 2362 – 2598) and 2259 (606)g (95% CI = 2136 – 2382) in wet and dry seasons respectively P < 0.02. Mean birth weight was significantly higher in multiparous compared to either primiparous or grand multiparous women. Together, mothers in high social class delivered twins with significantly higher mean birth weight than those of mothers in low social class p < 0.01. Conclusion: Overall mean birth weight of twins was 2392 (SD 560)g and it was significantly influenced by maternal parity and social class. Irrespective of gender, twin babies born during the wet season tended to be heavier than their counterparts born during the dry season.
Sahel Medical Journal Vol. 11 (4) 2008: pp. 137-141