Relationship between infant birth weight </=2000 g and maternal zinc levels at Muhimbili National Hospital, Dar Es Salaam, Tanzania.

The objective of this study was to determine the relationship between infant birth weight </=2000 g and maternal zinc status. The study was an unmatched case control. The study was conducted at Muhimbili National Hospital (MNH) in labor ward, from July to September 2002. The study population consisted infants with birth weight of <or=2000 g and their mothers as cases and infants with birth weight of >or=3000 g and their mothers formed the control group. There were 81 cases and 84 control infant-mother pairs. Maternal and infants venous blood samples were taken after delivery. Plasma zinc was analyzed using Atomic Absorption Spectrophotometer method. Data were analyzed using Epi-info version 6. Logistic regression was used to assess the contribution of other risk factor on infant birth weight. Date was converted to STATA format and logistic regression analysis was done using STATA program version 8. The results showed that there is significant relationship between infant birth weight and maternal zinc levels. Mothers with low zinc levels were two and half time more at risk of having an infant weighing <or=2000 g compared to those with normal zinc levels (OR 2.62, CI 1.36-5.73 p = 0.002). Cord blood zinc concentration was significantly lower in low birth weight compared to control babies. Infants with low zinc levels were almost three times more at risk of being born with birth weight <or=2000 g compared to those with normal zinc levels (OR 2.79, CI 1.36-5.73 p = 0.0016). This study indicated that there is a relationship between low infant birth weight <or=2000 g and maternal zinc deficiency. There is a relationship between infant birth weight and infant zinc levels. Maternal age of <or=19 years is associated with low infant birth weight and low maternal zinc levels. Plasma zinc level in mother correlated with plasma zinc level is their offspring.