Association between Maternal Exposure to Chemicals during Pregnancy and the Risk of Foetal Death: The Japan Environment and Children's Study.

Tadao Ooka,Sanae Otawa,Reiji Kojima,Zentaro Yamagata,Ryoji Shinohara,Yuka Akiyama,Sayaka Horiuchi,Kunio Miyake,Hiroshi Yokomichi

doi:10.3390/ijerph182211748

Abstract

Scarce knowledge is available on the relationship between maternal chemical exposure during pregnancy and foetal deaths. We studied the association of spontaneous abortions and stillbirths with occupational or daily maternal exposure to chemicals commonly used by pregnant women. Data from the Japan Environment and Children’s Study (JECS), a nationwide prospective birth cohort study, were used. The participants of the study were asked about the frequency of their use of gasoline, pesticides, hair dye, and chlorine bleach during the first and the second to third trimesters of pregnancy. We investigated the relationship between the frequency of the use of chemicals and foetal death. Of the 104,065 foetuses, 923 (0.91%) were spontaneous abortions and 379 (0.37%) were stillbirths. Any type of exposure during the first trimester was not significantly associated with spontaneous abortions. Nevertheless, a more than weekly occupational use of hair dye from the first to the second/third trimester was significantly associated with stillbirth. The results of this study suggest that the frequent use of hair dye during pregnancy can have severe adverse effects on the foetus. These findings can help pregnant women, especially hairdressers, refrain from the continuous use of hair dyes.

Highlights

Foetal deaths, including spontaneous abortion and stillbirth, are considered to be among the most common and severe complications of pregnancy
As an additional analysis to examine the relationship between occupation and foetal death, we examined the association between the maternal occupation of agriculture or hairdressing and the occurrence of spontaneous abortions and stillbirths
A body mass index (BMI) of 30 or higher increased the risk of spontaneous abortion, and a BMI of 25 or higher increased the risk of stillbirth

Summary

Introduction

Foetal deaths, including spontaneous abortion and stillbirth, are considered to be among the most common and severe complications of pregnancy. Foetal deaths have significant economic and psychosocial effects on parents, families, healthcare providers, and the society as a whole [1]. The incidence of spontaneous abortion is 12–15% annually [2], and stillbirth occurs in 1.8% of all recognised pregnancies annually, indicating that approximately 2.6 million stillbirths occur worldwide every year [3]. One of the major reasons for this is the knowledge gap on the causes and predictors of foetal death [5]. Previous studies have shown that maternal complications, such as age, obesity, hypertension, and diabetes, as well as maternal habits such as smoking are attributed to spontaneous abortion [2] and stillbirths [6,7]

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