Racial and ethnic disparities in fecundability: a North American preconception cohort study

Area of Science:

• Reproductive Health
• Epidemiology
• Health Disparities

Background:

• Previous US studies indicate Black women face longer waits for fertility treatment and are less likely to seek infertility care.
• Existing research on racial and ethnic variations in fecundability (per-cycle conception probability) is limited and shows conflicting results.
• Understanding these disparities is crucial for addressing reproductive health inequities.

Purpose of the Study:

• To investigate the extent of racial and ethnic disparities in fecundability among individuals trying to conceive in North America.
• To compare the per-cycle probability of conception across different racial and ethnic groups.

Main Methods:

• Analysis of data from the Pregnancy Study Online (PRESTO) cohort, including 18,573 US and Canadian residents aged 21-45 trying to conceive without fertility treatment.
• Self-reported race and ethnicity data collected at enrollment, with bimonthly follow-up for up to 12 months to track pregnancy status.
• Estimation of fecundability ratios (FRs) using proportional probabilities regression models, with sensitivity analyses for loss-to-follow-up and subgroup restrictions.

Main Results:

• Non-Hispanic Black participants showed significantly lower fecundability (FR=0.60) compared to non-Hispanic White participants.
• Lower fecundability was also observed in non-Hispanic American Indian/Alaskan Native/Indigenous (FR=0.70) and Hispanic other/unknown race (FR=0.77) groups.
• The 12-cycle cumulative incidence of infertility was substantially higher for non-Hispanic Black (33.2%) and Hispanic other/unknown race (29.7%) participants compared to non-Hispanic White participants (16.4%).

Conclusions:

• Significant racial and ethnic disparities in fecundability were observed in a North American preconception cohort.
• Broad racial/ethnic groupings may obscure heterogeneity within subgroups, and loss-to-follow-up introduced potential selection bias.
• Findings highlight the need for further research into mechanisms driving these disparities and for targeted programs to advance reproductive health equity.