Maternal BMI during Pregnancy: Effect on trace elements Status and Pregnancy Outcomes

Purpose: To investigate the effects of maternal prenatal body mass index (BMI) on trace elements (copper, iron and zinc) status, haematological parameters and pregnancy outcomes among pregnant women in Abakaliki, south-eastern Nigeria. Methods: Plasma levels of copper, iron and zinc of 349 pregnant women (gestational age ≤25 weeks; mean = 21.77±3.14 wks; aged = 15-45 years, mean = 27.04±4.75 yr) were analysed using flame atomic absorption spectrophotometer while haematological and biochemical parameters were determined using standard laboratory techniques. Results: Four women (1.1%) were underweight, 40.7% had normal BMI, 35.5% were overweight, 17.2% were obese and 5.4% were morbidly obese. Maternal BMI was significantly positively related to age, parity and socioeconomic status. While a negative relationship was found between plasma copper and maternal BMI, significantly (p < 0.05) lower zinc levels were found in underweight and obese women when compared to women with normal BMI. Maternal anaemia was significantly lower in overweight/obese women. Also maternal BMI was related to one adverse pregnancy outcomes. Conclusion: Both high and low prenatal BMI are associated with alterations in trace element status, haemoglobin concentrations and adverse pregnancy outcomes. In the face of concurrent deficiencies of micronutrient in this population, as in most developing countries, it appears that maintenance of appropriate weight and food diversification/fortification during pregnancy would be alternative ways of mitigating the consequences associated abnormal prenatal weight.