Aarhus University Seal / Aarhus Universitets segl

Age and fecundability in a North American preconception cohort study

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

  • Amelia K. Wesselink, Boston Univ, Boston University, Sch Publ Hlth, Dept Epidemiol
  • ,
  • Kenneth J. Rothman, RTI Hlth Solut, Research Triangle Institute
  • ,
  • Elizabeth E. Hatch, Boston Univ, Boston University, Sch Publ Hlth, Dept Epidemiol
  • ,
  • Ellen M. Mikkelsen
  • Henrik T. Sorensen
  • Lauren A. Wise

BACKGROUND: There is a well-documented decline in fertility treatment success with increasing female age; however, there are few preconception cohort studies that have examined female age and natural fertility. In addition, data on male age and fertility are inconsistent. Given the increasing number of couples who are attempting conception at older ages, a more detailed characterization of age-related fecundability in the general population is of great clinical utility.

OBJECTIVE: The purpose of this study was to examine the association between female and male age with fecundability.

STUDY DESIGN: We conducted a web-based preconception cohort study of pregnancy planners from the United States and Canada. Participants were enrolled between June 2013 and July 2017. Eligible participants were 21-45 years old (female) or >= 21 years old (male) and had not been using fertility treatments. Couples were followed until pregnancy or for up to 12 menstrual cycles. We analyzed data from 2962 couples who had been trying to conceive for

RESULTS: Among female patients, the unadjusted cumulative pregnancy proportion at 6 cycles of attempt time ranged from 62.0% (age 28-30 years) to 27.6% (age 40-45 years); the cumulative pregnancy proportion at 12 cycles of attempt time ranged from 79.3% (age 25-27 years old) to 55.5% (age 40-45 years old). Similar patterns were observed among male patients, although differences between age groups were smaller. After adjusting for potential confounders, we observed a nearly monotonic decline in fecundability with increasing female age, with the exception of 28-33 years, at which point fecundability was relatively stable. Fecundability ratios were 0.91 (95% confidence interval, 0.74-1.11) for ages 25-27, 0.88 (95% confidence interval, 0.72-1.08) for ages 28-30, 0.87 (95% confidence interval, 0.70-1.08) for ages 31-33, 0.82 (95% confidence interval, 0.64-1.05) for ages 34-36, 0.60 (95% confidence interval, 0.44-0.81) for ages 37-39, and 0.40 (95% confidence interval, 0.22-0.73) for ages 40-45, compared with the reference group (age, 21-24 years). The association was stronger among nulligravid women. Male age was not associated appreciably with fecundability after adjustment for female age, although the number of men >45 years old was small (n = 37).

CONCLUSION: In this preconception cohort study of North American pregnancy planners, increasing female age was associated with an approximately linear decline in fecundability. Although we found little association between male age and fecundability, the small number of men in our study >45 years old limited our ability to draw conclusions on fecundability in older men.

Original languageEnglish
Article numberARTN 667.e1-e8
JournalAmerican Journal of Obstetrics and Gynecology
Number of pages8
Publication statusPublished - Dec 2017

    Research areas


See relations at Aarhus University Citationformats

ID: 121630511