Gender differences in fetal growth of newborns exposed prenatally to airborne fine particulate matter

Abstract

Our primary purpose was to assess sex-specific fetal growth reduction in newborns exposed prenatally to fine particulate matter. Only women 18–35 years of age, who claimed to be non-smokers, with singleton pregnancies, without illicit drug use and HIV infection, free from chronic diseases were eligible for the study. A total of 481 enrolled pregnant women who gave birth between 37 and 43 weeks of gestation were included in the study. Prenatal personal exposure to fine particles over 48 h during the second trimester was measured using personal monitors. To evaluate the relationship between the level of PM2.5 measured over 48 h in the second trimester of pregnancy with those in the first and the third trimesters, a series of repeated measurements in each trimester was carried out in a random subsample of 85 pregnant women. We assessed the effect of PM2.5 exposure on the birth outcomes (weight, length and head circumference at birth) by multivariable regression models, controlling for potential confounders (maternal education, gestational age, parity, maternal height and prepregnancy weight, sex of infant, prenatal environmental tobacco smoke, and season of birth). Birth outcomes were associated positively with gestational age, parity, maternal height and prepregnancy weight, but negatively with the level of prenatal PM2.5 exposure. Overall average increase in gestational period of prenatal exposure to fine particles by about 30 μg/m3, i.e., from 25th percentile (23.4 μg/m3) to 75th percentile (53.1 μg/m3) brought about an average birth weight deficit of 97.2 g (95% CI: −201, 6.6) and length at birth of 0.7cm (95% CI: −1.36, −0.04). The corresponding exposure lead to birth weight deficit in male newborns of 189 g (95% CI: −34.2, −343) in comparison to 17 g in female newborns; the deficit of length at birth in male infants amounted to 1.1 cm (95% CI: −0.11, −2.04). We found a significant interrelationship between self-reported ETS and PM2.5, however, none of the models showed a significant interaction of both variables. The joint effect of various levels of PM2.5 and ETS on birth outcomes showed the significant deficit only for the categories of exposure with higher component of PM2.5. Concluding, the results of the study suggest that observed deficits in birth outcomes are rather attributable to prenatal PM2.5 exposure and not to environmental tobacco smoke. The study also provided evidence that male fetuses are more sensitive to prenatal PM2.5 exposure and this should persuade policy makers to consider birth outcomes by gender separately while setting air pollution guidelines.

Sex-specific differences in fetal growth in newborns exposed prenatally to traffic-related air pollution in the PELAGIE mother–child cohort (Brittany, France)

“…Few studies have explored the biological pathways that might explain the greater susceptibility of male fetuses to air pollution (Clougherty, 2010;Jedrychowski et al, 2009). A recent study has suggested that they may be more vulnerable than females to maternal oxidative stress (Minghetti et al, 2013).…”

“…Furthermore, growing evidence suggests these mechanisms may differ according to the fetus's sex (Bolton et al, 2014). Sex-linked traits (e.g., hormonal status and body size) influence both biological responses to exposure to environmental toxicants and the biological transport of these environmentally derived chemicals (Clougherty, 2010), and male newborns are suggested to be more vulnerable to prenatal exposure to air pollution (Jedrychowski et al, 2009;Ghosh et al, 2007;Lakshmanan et al, 2015). Because these biological differences in toxicology begin at the embryo stage, it appears necessary to assess sex-specific air pollution effects on fetal growth.…”

Effects of Ambient Air Pollution on Birth Outcomes: An Overview

“…In another study conducted in southern Sweden Downloaded by [University of Chicago Library] at 10:34 08 December 2014 Ambient Air Pollution and Birth Outcomes: An Overview 755 no correlation was observed between the various environmental pollutants, such as SO 2 and NO, and PTD or LBW (Landgren, 1996). Furthermore, other researches have shown that air pollution exposure may induce toxic effects more frequently on female fetuses compared to male fetuses , while in another research the opposite result has been observed (Jedrychowski et al, 2009). Conflicting data have been also reported as regards the role of pregnancy time, in particular considering the exposure during the first, mid, and last trimester or the whole period (Bell et al, 2007;Bobak, 2000;Wang et al, 1997).…”

“…By contrast only recently, the scientific community has addressed studies regarding the possible effects of environmental pollutants on pregnant women health and birth outcomes. These studies have been performed by the association between AAP exposure and the appearance of many diseases affecting fetal development, such as preterm birth delivery (PTD, <37 weeks), low birth weight (LBW, <2500 g), very low birth weight (VLBW, <1500 g), intrauterine growth restriction (IUGR), intrauterine mortality (IUM), congenital anomalies (CA; Figure 1; Dejmek et al, 1999;Gray et al, 2009;Ha et al, 2001;Hansen et al, 2006;Jedrychowski et al, 2009;Leem et al, 2006;Liu et al, 2003;Llop et al, 2010;Maisonet et al, 2001;Maroziene and Grazuleviciene, 2002;Morello-Frosch et al, 2010;Ritz et al, 2007;Rogers and Dunlop, 2006;Salam et al, 2005;Wu et al, 2009;Yang et al, 2003).…”

Ambient Air Pollution and Reproductive Health

“…However, little has been done to examine the potential modifiers of the health effects of air pollution on birth outcomes. Limited evidence suggests that the effect sizes of air pollution on adverse pregnancy outcomes may be different by fetal gender Jedrychowski et al 2009), pregnancy complication (Rich et al 2009), and maternal nutrition (Jedrychowski et al 2007;Kannan et al 2006). Much remains to be learned about these relationships and what else could cause fetuses to be especially sensitive to the adverse health effects of air pollution.…”