Relationship between lead concentration in maternal and umbilical cord blood and some neonatal outcomes in primiparous opium-dependent mothers in Zahedan, Southeast of Iran in 2022

BACKGROUND: There are limited studies on maternal and umbilical cord blood lead levels and their relationship with each other and with pregnancy outcomes in women addicted to opium. The present study was conducted with the aim of investigating the relationship between lead concentrations in maternal blood and umbilical cord blood with some neonatal outcomes in primiparous opium-dependent mothers. METHOD: The present study is a cross-sectional and analytical research. A total of 35 mothers addicted to opium and 35 women without addiction from Zahedan city of Iran participated in this study in 2022. Convenience sampling was done, lead levels were measured and pregnancy outcomes checked by a checklist to collect information. Data analysis was done by independent t-tests, Pearson’s correlation coefficient, Point-Biserial Correlation Coefficient, multivariate linear regression and multivariate logistic regression using SPSS version 26 software. RESULTS: There was a significant difference in maternal blood lead levels (24.97 ± 8.45 in addicted mothers and 7.5 ± 4.25 in healthy mothers) and in umbilical cord blood lead concentrations (18.68 ± 6.95 in the addicted group and 5.7 ± 2.84 in the healthy group) between the two groups (P < 0.0001 and P < 0.0001, respectively).The lead concentration of all the samples in the addicted group was higher than the high-risk levels. Birth weight, Apgar score, admission to NICU and need for resuscitation were significantly different between the two groups (P < 0.0001, P < 0.0001, p = 0.03 and p = 0.04, respectively). Based on the results of multivariate linear regression test, only addiction can reversely predict the birth weight (Beta= -0.74, P < 0.0001), 1-minute Apgar score (Beta = -0.47, P = 0.004) and 5th minute (Beta= -0.62, P = 0.001). According to multivariate logistic regression test, OR of none of the predictor variables was significant with the outcomes. Maternal and umbilical cord blood lead concentrations were not predictors of pregnancy outcomes. CONCLUSION: The use of opium during pregnancy leads to an increase in the level of lead in maternal blood and umbilical cord blood. Addiction increased adverse pregnancy outcomes but lead concentration did not predict pregnancy complications. It is recommended that the addiction treatment program be included in pre-pregnancy and pregnancy care plans.