Prenatal exposure to extremely low frequency magnetic field and its impact on fetal growth

Yanfeng Ren,Ziliang Wang,Hong Liang,Wei Yuan,Xiaowei Sun,Jianping Chen,De-Kun Li,Maohua Miao,Fen Yang

doi:10.1186/s12940-019-0447-9

Abstract

ObjectiveStudies on the effect of prenatal exposure to magnetic field (MF) on fetal growth is inconclusive and subject to some methodological limitations, particularly in measurement of MF exposure. The present study aimed to examine the association between maternal extremely low frequency MF (ELF-MF) exposure during pregnancy and fetal growth in offspring.MethodsA total of 128 pregnant women were recruited at their 3rd trimester and asked to wear an EMDEX Lite meter for 24 h to capture daily ELF-MF exposure. Time-weighted average (TWA), P50, and P75 of personal 24-h measurements were used to evaluate prenatal ELF-MF exposure. The medians of these measurements were used as cut-off points of high and low prenatal ELF-MF exposure. Fetal growth was measured by infant’s birth weight, skinfold thickness of triceps, abdomen, and back, and circumference of head, upper arm, and abdomen. These measures were conducted within 24-h after birth. Generalized Linear Model was used to examine the association between maternal ELF-MF level and fetal growth indices after potential confounders were adjusted for.ResultsCompared with girls with lower prenatal ELF-MF exposure, girls with higher exposure had a lower birth weight, thinner skinfold of triceps, abdomen and back, and smaller circumference of head, upper arm and abdomen in all three ELF-MF matrices. The differences were statistically significant for birth weight and most other growth measurements (P < 0.05). These measures had no significant difference between higher and lower prenatal ELF-MF exposure in boys except back skinfold thickness.ConclusionPrenatal exposure to higher ELF-MF levels was associated with decreased fetal growth in girls, but not in boys.

Highlights

Magnetic field (MF) is a physical field produced by electrically charged objects and extends indefinitely throughout space by the electromagnetic interaction [1]
Several studies have examined the associations between prenatal extremely low frequency MF (ELF-MF) exposure and low birth weight (LBW), small for gestational age (SGA), or intrauterine growth retardation (IUGR) in offspring [10,11,12], with inconsistent results
We examined the association between maternal 24-h MF exposure at individual level, measured by a triple-axis device during the 3rd trimester, and fetal growth in offspring in a prospective cohort study

Summary

Introduction

Magnetic field (MF) is a physical field produced by electrically charged objects and extends indefinitely throughout space by the electromagnetic interaction [1]. As developing embryo and fetus are much more susceptible to environmental toxins including MF, many studies have focused on the impact of prenatal MF exposure on fetal growth as well as other health outcomes of offspring, such as miscarriage, obesity, asthma, etc. Birth weight is a strong predictor of infants’ mortality/ morbidity and has been regarded as a convenient surrogate for fetal growth [9]. Several studies have examined the associations between prenatal ELF-MF exposure and low birth weight (LBW), small for gestational age (SGA), or intrauterine growth retardation (IUGR) in offspring [10,11,12], with inconsistent results. One study investigated the relationships between ELF-MF exposure and other fetal growth indices including fetal length and head circumference, but no association was found [13]

Methods

Results

Conclusion