Is glycosylated haemoglobin a marker of fertility? A follow-up study of first-pregnancy planners

Abstract

We performed a follow-up study of time to pregnancy in a population of first-time pregnancy planners without previous reproductive experience. The objective of this paper is to report and discuss a finding of a strong relationship between glycosylated haemoglobin (HbA(1C)) and fertility. A total of 165 Danish couples without previous reproductive experience was followed from termination of birth control until pregnancy for a maximum of six menstrual cycles, HbA(1C) and reproductive hormones were measured at entry. Questionnaire data were collected at entry and once in each cycle during follow-up. The odds ratio (OR) for pregnancy per cycle decreased with increasing concentration of HbA(1C) (OR per percent HbA(1C) 0.4, 95% CI 0.2-0.9 for all six cycles and 0.2, 95% CI 0.1-0.5 in the first three cycles). A high concentration of HbA(1C) was associated with a high concentration of testosterone and a low concentration of inhibin A. No association was found between HbA(1C) and psychosocial distress. The reduced fertility among women with high HbA(1C) may be due to an association with subclinical polycystic ovaries as indicated by the hormonal profile.