The effects of sex, birthweight, birth order and maternal age on infant mortality in a Nigerian community.

Corrected registration returns in a rural area of Nigeria show that the average infant mortality rate during one five year period was 88.2 per 1000 per annum. The rate was 89.4 per 1000 for females, which did not differ significantly from that of 87.0 per 1000 for males. There were significant variations in the rates by maternal age and by birth order. Forty-two per cent of the infant deaths were of low birth-weight, the mortality rate among this group being approximately six times as high as for those with greater weights.