Nutritional Status in Pregnancy and Prediction of Low Birth Weight: Evaluation of a Table of Reference

Abstract

Context: Maternal nutrition, before and during pregnancy is an important determinant of birth weight and the high rate of low birth weight (LBW) in developing countries has been attributed to poor maternal nutrition. Maternal nutrition is difficult to assess during pregnancy because of the physiological alterations, yet there is the need to identify women whose weight profile suggest the delivery of LBW babies.


Objective: A reference standard of weight for height by week of pregnancy has been developed specifically for pregnant women in Ibadan. The validity of this table in predicting LBW is being evaluated.


Study Design, Setting and Subjects: The data of 255 pregnant women who attended the University College Hospital, Ibadan for antenatal and delivery care between 1996 and 1999 were used to test the validity of a reference table in predicting LBW. The maternal weight at 26wks, 34wks and 39/40wks was compared with the predicted weight for specific height in the reference table. The maternal weights at those points in gestation were correlated with delivery of LBW infants.


Results: The accuracy of this table of reference in predicting LBW is described by a sensitivity of 50% at 26 weeks and 33% at 39/40weeks; a specificity of 93% at 26weeks and 100% at 39/40weeks and an overall accuracy of 92% at 26wks and 96% at 39/40wks.

Conclusion: The table of reference of weight for height by week of gestation, despite its limitations, comes useful in antenatal care settings in identifying women at risk of delivering LBW infants.



Key Words: Nutrition, Pregnancy, Maternal Weight, Birthweight


[Trop J Obstet Gynaecol, 2002, 19: 63-67]