Negative Effects of Maternal Smoking on Pregnancy and the Fetus in Relation to Elevated Levels of Erythropoetin in Umbilical Cord Plasma

Introduction: Based on many scientific research studies, there has been demonstrated a relation between smoking of pregnant women and its negative effects on pregnancy, intrauterine fetal growth, postnatal newborn condition, and development. The aim of our study is to highlight the adverse effects of cigarette use during pregnancy and to evaluate the effect of maternal smoking on the levels of erythropoietin (EPO) in umbilical cord plasma. Our aim was to show an effect of maternal smoking by determining carboxyhemoglobin (COHb) levels in maternal blood, too. Design: Prospective analysis. Setting: Department of Gynecology and Obstetrics, Jessenius Faculty of Medicine, Comenius University, Martin, Slovak Republic. Methods: Our study included 174 newborns. Mothers were divided into group of smokers (n = 67) and non-smokers (n = 107). This prospective study was realized from February 2012 to November 2013 at the Department of Gynecology and Obstetrics, Jessenius Faculty of Medicine in Martin, Slovak Republic. Patients signed a written informed consent and completed a questionnaire that involved medical history, and data of their smoking habits. EPO levels were measured in 174 samples of umbilical cord plasma. Infants were born spontaneously at term. Results: We observed significantly higher EPO levels in umbilical cord plasma in children born to smokers in contrast to non-smokers’ (children of non-smoking mothers: 19 ± 8 mIU/mL;children of smokers: 61 ± 33 mIU/mL, p < 0.01). The COHb levels were significantly higher in smokers (non-smokers: 0.8% ± 0.4%;smokers: 3.6% ± 1.1%, p < 0.001). Conclusion: Smoking during pregnancy is associated with elevated EPO concentrations in umbilical cord plasma at the time of birth. Based on the results of our study, we would like to support women planning pregnancy and pregnant women to quit smoking. Closer surveillance is recommended in smoking pregnant women, particularly because of the risk of placental insufficiency and fetal growth retardation.

Maternal smoking status during pregnancy and low birth weight in offspring:systematic review and meta-analysis of 55 cohort studies published from 1986 to 2020

Background Maternal smoking during pregnancy may be associated with low birth weight(LBW)in offspring and global risk estimates have not been summarized previously.We aimed to systematically explore evidence regarding maternal smoking and the LBW risk in offspring globally and examine possible causes of heterogeneity across relevant studies.Methods Comprehensive search of PubMed,Ovid Embase,Ovid Medline(R),and Web of science from inception until October 2021 was carried out.A random-effects meta-analysis was used to estimate the pooled odds ratio(OR)and corresponding 95%confidence interval(CI).Restricted cubic spline analysis with three knots was used to further examine the dose-response relationship.Results Literature searches yielded 4940 articles,of which 53 met inclusion criteria(comprising 55 independent studies).Maternal smoking during pregnancy was significantly associated with the risk of LBW in offspring(OR=1.89,95%CI=1.80-1.98).Furthermore,an obvious dose-response relationship between the amount of cigarettes daily smoked in pregnancy and the risk of LBW in offspring was observed.The results of subgroup analyses indicated that the risk of maternal smoking on LBW was larger in more recently conducted studies(P=0.020)and longer period of active smoking during pregnancy(P=0.002).No evidence of publication bias was found.Conclusions In summary,maternal smoking in pregnancy was significantly associated with a higher risk of LBW in offspring on a global scale.The risk of maternal smoking on infant LBW seems to be increasing over time,and was higher with longer smoking duration throughout pregnancy and more cigarettes smoked daily.