Maternal mid-arm circumference and other anthropometric measures of adiposity in relation to infant birth size among Zimbabwean women.

Background: To examine relationships between maternal anthropometric measures in Zimbabwean women and indices of infant birth size.

Methods: We conducted a cross-sectional study of pregnant women admitted for labor and delivery at the Harare Maternity Hospital from July 1998 to March 1999. The study population was comprised of 498 participants who delivered singleton infants. Anthropometric measures (height, weight, and mid-arm circumference) were taken during participants' postpartum hospital stay. Logistic regression and least-squares regression procedures were used to assess the association of maternal measures with infant size.

Results: Women in the highest weight quartile (>67 kg) were 58% less likely to have a low-birth-weight infant when compared to women in the lowest quartile (<57 kg) (OR = 0.42, 95% CI 0.19-0.90). Women in the highest body mass index quartile were 75% less likely to have a low-birth-weight infant compared to women in the lowest quartile (>27 versus <23 kg/m2: OR = 0.25, 95%CI 0.10-0.60). Similar trends were seen for risk of low birth weight in relation to mid-arm circumference. Maternal mid-arm circumference was most strongly related with the four infant size indices measured. Each unit increase in maternal mid-arm circumference resulted in a 36.1-g increase in infant birth weight (p<0.001). In general, women who were heavier at the time of delivery were less likely to have a low-birth-weight infant than women who were lighter.

Conclusions: In areas where food security is a public health concern, as it is in most parts of the developing world, pregnant women may not be meeting their own nutritional needs and those of their fetus.