Environment/Climate Change
Investigating the relationship between ambient temperature and reproductive hormonal changes among women attempting pregnancy Kaniz Rabeya* Kaniz Rabeya Neil J. Perkins Lindsey M. Russo Pauline Mendola Timothy P. Canty Karen C. Schliep Carrie J. Nobles
Background: High ambient temperatures have been associated with adverse reproductive and pregnancy outcomes, however, the role of hormones has been understudied. We investigated the association between ambient temperature and reproductive hormones among women trying to get pregnant.
Method: A prospective time-to-pregnancy study (EAGeR trial, 2006-2012) enrolled 1228 women from Buffalo, Scranton, Denver, and Salt Lake City. Daily temperature was collected from weather monitoring stations and averaged across an early-to-mid follicular phase window (1-10 days after menses) and ovulation window (11-16 days). Daily diaries and fertility monitors tracked timing of menstrual cycles and ovulation. Estrone-3-glucuronide, estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, and pregnanediol glucuronide were measured in urine at ovulation and in the luteal phase (8 days after ovulation) in the first menstrual cycle. Generalized linear models estimated the association between temperature and hormones by warm (Apr. 1-Sept. 30) vs. cold (Oct. 1-Mar. 31) seasons adjusting for fine particulate matter and ozone.
Result: During the warm season, women exposed to 1°C higher ambient temperature in the early-to-mid follicular phase and ovulation windows had -0.03 (95% CI, -0.14, 0.08) ng/mL lower FSH and -0.12 (95% CI, -0.23, -0.01) ng/mL lower LH, respectively, at ovulation. Conversely, a 1°C increase of temperature in the cold season during the early-to-mid follicular phase and ovulation windows was associated with 0.15 (95% CI, 0.02, 0.28) ng/mL higher FSH and 0.12 (95% CI, 0.004, 0.24) ng/mL higher LH, respectively, at ovulation. Higher estradiol at ovulation was observed with higher temperatures in both seasons. Few associations were found during the luteal phase.
Conclusion: Both higher and lower temperatures were associated with lower FSH and LH at ovulation, suggesting hormones may be a sensitive pathway for impacts on reproductive health.