Maternal age at birth and daughter's fecundability

Area of Science:

• Reproductive Health
• Human Fertility
• Epidemiology

Background:

• Limited retrospective studies exist on maternal age and daughter's fecundability.
• Some evidence suggests daughters of older mothers may have reduced fertility.

Purpose of the Study:

• To investigate the association between maternal age at birth and daughter's fecundability.
• To provide data on fertility trends in relation to maternal age.

Main Methods:

• Prospective cohort study of 6,689 North American pregnancy planners (PRESTO).
• Maternal age at participant's birth was analyzed using multivariable proportional probabilities regression models.
• Fecundability ratios (FR) were estimated.

Main Results:

• No significant association was found between maternal age ≥35 years and daughter's fecundability.
• Daughters of mothers <25 years had higher rates of prior unplanned pregnancies and longer time to attempt conception.
• Fecundability ratios varied across maternal age groups, with a notable FR of 0.72 for maternal age <20 years compared to 25-29 years.

Conclusions:

• Maternal age of 35 years or older at childbirth is not associated with lower daughter fecundability, which is reassuring given delayed childbearing trends.
• Being born to a young mother (<25 years) may be a marker for lower fecundability in pregnancy planners.
• Potential selection bias due to differences in reproductive history and loss to follow-up warrants consideration.