- Up to 25% of all clinically recognized pregnancies, those usually past the first trimester, will end in a spontaneous abortion.
- Two avoidable factors, both related to obesity, are known to increase the rate of spontaneous abortions are hypertension and diabetes.
- Exposure to aniline derivatives included in hair dye and chlorine bleach should be added to this list.
- Chemicals we willingly use on our skin may produce more abortions and stillbirths than we would like to acknowledge.
Chemicals in soaps, cleaners, and food are known to cause spontaneous abortion and stillbirths. Spontaneous abortion is the loss of a pregnancy without outside intervention before 20 weeks of gestation. A stillbirth is when a baby is born dead after 24 weeks of pregnancy. These are not rare events. Up to 25 percent of all clinically recognized pregnancies, that is, those usually past the first trimester, will end in a spontaneous abortion while approximately 2 percent end with stillbirths. The actual number is likely considerably higher due to the fact that most spontaneous abortions occur prior to the pregnancy being recognized.
Two avoidable factors, both related to obesity (BMI >30), are known to increase the rate of spontaneous abortions are hypertension and diabetes. Exposure to chemicals in tobacco smoke and pesticides also contribute. Aniline derivatives included in hair dye and chlorine bleach should now be added to this list of avoidable factors.
A recent study investigated the effects of chemicals that are frequently present in women’s daily lives or occupations on spontaneous abortion and stillbirths. The study considers data collected on confirmed 104,065 fetuses from 97,415 mothers. The study focused on hair dyes but also monitored exposure to numerous other potential toxins. The focus on hair dyes was because a recent analysis of hairdressers determined that their profession is significantly associated with the occurrence of fetal death throughout gestation. The authors considered daily exposure to hair dye, exposure frequency both at home and at a beauty salon. Regarding the daily exposure to hair dye, the authors queried the women about the exposure frequency both at home and at a hair salon, with the options: ‘Never.’ ‘Rarely.’ ‘Sometimes.’ ‘Quite often.'
The study discovered that total maternal exposure to hair dye was significantly associated with spontaneous abortion and stillbirths. Interestingly, chemical exposure during the first trimester was not associated with a significant increase in the risk of spontaneous abortion or stillbirth. The failure of fertilized ovum to implant during the first trimester is usually due to the presence of genetic mutations. In contrast, during the second and third trimesters, the risk of stillbirths significantly increased as the frequency of exposure increased. The authors considered the role of exposure to other chemical toxins in the women’s environment but found a significant risk only for the aniline derivatives in hair dyes.
Aniline derivatives are used as tints and for removing unwanted tones. Previous studies have already demonstrated that aniline derivatives, such as paraphenylenediamine, have severe adverse effects on human health. Aniline derivatives are easily absorbed through dry or abraded skin, or when dissolved in moisturizing agents, and cause methemoglobinemia. Methemoglobin is a form of hemoglobin that cannot carry oxygen. Fetuses are more susceptible to methemoglobinemia because fetal hemoglobin is easily converted into methemoglobin leading to severe chronic oxygen deprivation in the fetus resulting in stillbirth.
Exposure to environmental toxins induces in utero fetal death far more often than is currently appreciated. Fetal deaths have significant economic and psychosocial effects on parents, families, healthcare providers, and society. Any future legislation limiting medical termination of pregnancy must not ignore the far more significant role of the industries that produce chemicals used in dyes, cleaning products, and personal hygiene.
Ooka, T et al., (2021) Association between maternal exposure to chemicals during pregnancy and the risk of foetal death: The Japan Environment and Children’s Study. Int. J. Environ. Res. Public Health, 18, 11748. https://doi.org/10.3390/ijerph182211748
Henrotin J-B, et al., (2015) Reproductive disorders in hairdressers and cosmetologists: A meta-analytical approach. J Occupational Health, Vol 57, 485–496.