Postmenopausal women reporting a history of at least four pregnancies were 28% more likely to develop diabetes when compared with women who reported two or three pregnancies, according to an analysis of National Health and Nutrition Examination Survey data.
“Prior studies on the association between pregnancy and risk for diabetes in women have reported discordant results,” Ningjian Wang, MD, PhD, associate professor in the department of endocrinology and metabolism at Shanghai Ninth People’s Hospital and Shanghai JiaoTong University School of Medicine, China, told Endocrine Today. “Multiple pregnancies (≥ 4) through child-bearing age may be a potential risk factor for diabetes in postmenopausal women without a history of gestational diabetes.”
Wang and colleagues analyzed data from 9,138 postmenopausal women with no history of gestational diabetes participating in the 1999-2014 NHANES surveys. Participants provided blood samples to measure HbA1c and completed a 75-g oral glucose tolerance test. History of pregnancy was assessed via questionnaire, with responses categorized into four groups: two to three pregnancies (n = 3,646), no pregnancy (n = 610), one pregnancy (n = 830) and at least four pregnancies (n = 4,052). Researchers used linear regression analysis to calculate the association between number of pregnancies and parameters of glucose metabolism.
Researchers found that the prevalence of diabetes was higher among women reporting at least four pregnancies vs. women reporting two to three pregnancies (28.4% vs. 20.7%; P < .001). Diabetes prevalence was also marginally higher among women reporting no pregnancies vs. women reporting two to three pregnancies (23.8% vs. 20.7%; P = .086).
In linear regression analysis, researchers found that women reporting at least four pregnancies were 28% more likely to develop diabetes vs. women reporting two to three pregnancies (OR = 1.28; 95% CI, 1.1-1.48), with results persisting after adjustment for multiple factors, including age, race, BMI, age at menarche, age at menopause and use of hormone therapy. Similarly, women reporting no pregnancy were 31% more likely to develop diabetes vs. women reporting two to three pregnancies in the adjusted analysis (OR = 1.31; 95% CI, 1.01-1.71).
Researchers also observed that women reporting at least four pregnancies had a higher fasting plasma glucose, HbA1c and 2-hour plasma glucose and were more insulin resistant vs. women reporting two to three pregnancies (P < .001 for all).
“Intriguingly, it is worth mentioning that previous studies did not focus on postmenopausal women; thus, women in those studies may have another pregnancy later in life,” the researchers wrote. “However, our study has included all the pregnancies in the women’s entire lives, and, accordingly, might offer women in childbearing age more scientific reproductive advice.” – by Regina Schaffer
For more information:
Ningjian Wang, MD, PhD, can be reached at the Department of Endocrinology and Metabolism, Shanghai Ninth People’s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 2000011, China; email: firstname.lastname@example.org.
Disclosures: The authors report no relevant financial disclosures.