Stress Before Conception can Affect the Health of Women Undergoing Fertility Treatment

Stress during pregnancy is known to affect health, but a new study suggests that pre-pregnancy stress levels are also important to assess. The researchers from Massachusetts General Hospital and Brigham and Women’s Hospital examined the relationship between self-reported stress immediately before conception in women seeking fertility treatment and blood glucose levels, a marker of heart health. The team found that maternal stress prior to conception was associated with higher blood glucose levels, particularly in women who underwent intrauterine insemination to conceive and in women of higher socioeconomic status. The results were published in the Journal of the Endocrine Society.

How Stress Affects Fertility

It’s no secret that stress can have a negative impact on fertility. In fact, it affects the release of hormones that hinder or impede natural conception. Women, for example, may not ovulate, while men often suffer from a low sperm count. The prevalence of stress has increased over the years, particularly among couples who are unable to conceive naturally. Mínguez-Alarcón, a reproductive epidemiologist in Brigham’s Channing Division of Network Medicine and co-investigator of the Environmental and Reproductive Health Study (EARTH), and her colleagues analyzed data from the EARTH study, which was conducted from 2004 to 2019 at the Massachusetts General Hospital Fertility Center and involved 398 women between the ages of 18 and 45. At the start of the study, the women self-reported that they had experienced stress prior to conception. Additional clinical characteristics and sociodemographic information, including family and medical history, use of consumer products and smoking, were collected either by study staff using medical records or questionnaires.

The average age of the women at baseline was 35 years, most were of white ethnicity (83 percent), reported never having smoked (78 percent) and had at least a college degree (64 percent). Three hundred of the women became pregnant through medically assisted technologies such as intrauterine insemination (IUI) or in vitro fertilization (IVF). In IUI, sperm is injected directly into the uterus, while IVF is a multi-step technology in which an egg is retrieved for fertilization in a laboratory and then returned to the uterus. The blood glucose test was carried out on average after 26 weeks of pregnancy and measured one hour after the women had drunk a 50-gram glucose solution. A blood glucose level of 140 mg/dL or less was considered normal.

The researchers found that blood glucose levels, a measure of cardiovascular health, were abnormally high in 82 of the women involved. Previous studies have shown that women who develop gestational diabetes during pregnancy have an increased risk of developing type 2 diabetes as well as cardiovascular problems later in life, including calcification of the heart arteries. The team found that women who experienced more stress before conception had higher blood sugar levels on average. In addition, women who became pregnant through IUI had both higher stress and blood sugar levels than women who became pregnant through IVF.

Results Relevant for Public Health

The study also found that women with a higher socioeconomic status during pregnancy had higher pre-conception stress levels and higher blood glucose levels. Median family income was used to measure socioeconomic status. The researchers explain this by the fact that working women with higher incomes and higher levels of education often work in demanding, time-consuming jobs, and often have to balance the demands of the workplace with household and childcare responsibilities. It has already been shown that women with a higher level of education suffer more from work-related stress. Since education level is positively associated with salary, it is possible that this explanation also applies to women with higher incomes.

However, the results are limited as the study is a group of predominantly white women of high socioeconomic status seeking fertility treatment. Self-reporting of perceived stress may also lead to participant bias. Future research may examine additional variables such as sleep quality or neighborhood safety, as well as the impact of pre-birth stress on the health of the baby.

For the researchers, these findings are relevant to public health as stress becomes more prevalent over the years, and has an impact on cardiovascular health. Women can try to reduce their stress levels through a number of strategies, such as increasing exercise, abstaining from alcohol and drugs, eating a healthy diet and avoiding isolation. Relaxation techniques such as yoga and meditation can also be helpful.