Alexandra Purdue-Smithe, PhD

Dr. Alexandra Purdue-Smithe is a reproductive and nutritional epidemiologist whose research focuses on the etiology of accelerated reproductive aging, early menopause, subfertility, and pregnancy complications. She earned her B.S. in Nutrition, M.S. in Epidemiology, and Ph.D. in Epidemiology from the University of Massachusetts Amherst. Before joining the Division of Women’s Health in 2021, Dr. Purdue-Smithe was an Intramural Research Training Award Postdoctoral Fellow in the Epidemiology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health.


Broadly, the goal of Dr. Purdue-Smithe’s research is to identify modifiable strategies to improve women’s health across the lifespan, with a specific focus on preconception health, pregnancy, and menopause. She is actively involved in the Society for Epidemiologic Research and the Society for Pediatric and Perinatal Epidemiologic Research. Dr. Purdue-Smithe has received awards from national professional societies including the American Public Health Association and her research has been featured internationally in the press.

Brigham & Women’s Hospital
Associate Epidemiologist, Division of Women’s Health, Department of Medicine,

Harvard Medical School
Instructor in Medicine

Areas of Expertise

Current Research

Dr. Purdue-Smithe’s current research seeks to identify potentially modifiable preconception dietary and lifestyle factors to improve pregnancy outcomes. Using data from prospective cohorts such as the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, Dr. Purdue-Smithe is currently investigating the role of nutrition and biological aging biomarkers in time-to-pregnancy, pregnancy loss, and offspring sex ratio. She is also particularly interested in the application of causal inference techniques to address methodologic and statistical complexities relevant to reproductive epidemiologic research.


Dr. Purdue-Smithe’s other recent work has examined associations of iodine status and thyroid function during pregnancy with pregnancy complications including stillbirth, preterm birth, and preeclampsia using Finnish population-based registry-linked prospective data.

Select Past Research

  • Early Menopause and Anti-Müllerian Hormone
    Examined associations of vitamin D and calcium intake, vitamin D biomarkers, and dairy consumption with risk of early menopause and anti-Müllerian hormone, a biomarker of ovarian reserve, among women in the Nurses’ Health Study 2 (NHS2).
  • Diet and Premenstrual Syndrome
    Investigated the relationship between caffeine and caffeinated beverage intake in the development of premenstrual syndrome in the NHS2.

Select Publications

Purdue-Smithe AC, Männistö T, Reische EC, Kannan K, Kim UJ, Suvanto E, Surcel HM, Gissler M, Mills JL. Iodine and thyroid status during pregnancy and risk of stillbirth: a population-based nested case-control study. Matern Child Nutr. 2021. (in press)


Purdue-Smithe AC, Kim K, Nobles CJ, Schisterman EF, Schliep KC, Perkins NJ, Sjaarda LA, Freeman JR, Robinson SL, Radoc JG, Mills JL, Silver RM, Ye A, Mumford SL. The role of maternal preconception vitamin D status in human offspring sex ratio. Nat Commun. 2021;12(1):2789. PMID: 33986298.


Purdue-Smithe AC, Männistö T, Bell G, Mumford SL, Liu A, Kannan K, Kim UJ, Suvanto E, Surcel HM, Gissler M, Mills JL. The joint role of thyroid function and iodine status on risk of preterm birth and small for gestational age: a population-based nested case-control study of Finnish women. Nutrients. 2019;11(11):2573. PMID: 31731400.


Purdue-Smithe AC, Mumford SL. Conflicting messages on diet and fertility: food for thought. Fertil Steril 2018;110(6):1037-38. PMID: 30396545.


Purdue-Smithe AC, Whitcomb BW, Manson JE, Hankinson SE, Rosner BA, Troy LM, Bertone-Johnson ER. A prospective study of dairy food intake and early menopause. Am J Epidemiol. 2019;188(1):188-96. PMID: 30239575.


Purdue-Smithe AC, Whitcomb BW, Manson JE, Hankinson SE, Troy LM, Rosner BA, Bertone-Johnson ER. Vitamin D status is not associated with risk of early menopause. J Nutr. 2018;148(9):1445-52. PMID: 30107585.


Purdue-Smithe AC, Whitcomb BW, Szegda KL, Boutot ME, Manson JE, Hankinson SE, Rosner BA, Troy LM, Michels KB, Bertone-Johnson ER. Intakes of vitamin D and calcium and risk of early menopause. Am J Clin Nutr. 2017;105:1493-1501. PMID: 28490509.


Purdue-Smithe AC, Manson JE, Hankinson SE, Bertone-Johnson ER. A prospective study of caffeine and coffee intake and premenstrual syndrome. Am J Clin Nutr. 2016;104(2):499-507. PMID: 27385613.