Investigation of Serum Levels of Maternal Heavy Metals and Adverse Birth Outcomes

Abstract

Women within reproductive stage are known to be exposed to heavy metals from various sources e.g. occupation, life-style, counterfeit drugs, etc. Contact with toxic metals has been linked with altered physiologic processes. The aim of this study is to assess the serum concentrations of heavy metals in third trimester pregnant women and relate them with birth weight. Forty pregnant women (in third trimester) were recruited at maternity centers within Osogbo metropolis, 40 healthy women, age-matched, non-pregnant served as control. Serum was obtained from 5 mL of blood taken from each participant. Inductively Coupled Plasma-Optical Emission Spectrometry was employed to estimate the concentrations of cadmium, chromium, aluminum, lead, arsenic, mercury, nickel, and cobalt. Pregnancy outcomes- birth weight and ratio of live and stillbirths- were also determined. Student’s t-test and Pearson’s correlation coefficient were used to analyze the data. P<0.05 was considered statistical significant. Results of the study revealed significant increase in the levels of heavy metals at third trimester compared with control. Mean birth weight was 2.39 ± 0.42 kg (normal: 2.5- 4.0) and the ratio of live birth to stillbirth was 9: 1. Cd (r= -0.443; p= 0.008) and nickel (r= -0.416; 0.013) were negatively correlated with birth weight. Data derived from the study indicate that elevated serum levels of maternal heavy metals may be a contributing factor to adverse birth outcomes as both were found to co-exist.