International Journal of Epidemiology 2002;31:349-358
© International Epidemiological Association 2002
Life Course Epidemiology |
Mother's age and daughter's fecundity. An epidemiological analysis of late 19th to early 20th century family reconstitutions
a Department of Epidemiology and Biostatistics, University Medical Center, Nijmegen, The Netherlands.
b Netherlands Interdisciplinary Demographic Institute, The Hague, The Netherlands.
c Department of Epidemiology, Universiteit Maastricht, Maastricht, The Netherlands.
Dr LJM Smits, Department of Epidemiology, Universiteit Maastricht, PO Box 616, 6200MD Maastricht, The Netherlands. E-mail: luc.smits{at}epid.unimaas.nl
Abstract
Background At both ends of the female reproductive span, the risk of reproductive problems is increased. We hypothesize that this is partly explained by inadequate maturation of oocytes (‘pre-ovulatory overripeness’). As this phenomenon has been shown to lead to gonadal anomalies in the offspring of animals, we tested the prediction that daughters of older and very young mothers more often suffer reproductive problems due to ovarian maldevelopment.
Methods We analysed family reconstitutions of 1907 women born in Rotterdam, the Netherlands, between 1873 and 1902. We defined several measures of fecundity based on numbers, birth rates and fates of offspring. We made use of general estimating equations (GEE), a statistical technique that allowed simultaneous analysis of different births per woman while controlling for various time-dependent or time-independent co-variables.
Results The results indicated an increased risk of childlessness (adjusted odds ratio (aOR = 2.6, 95% CI : 1.1–7.4), stillbirth (aOR = 2.5, 95% CI : 1.1–5.6) and multiple birth (aOR = 2.1, 95% CI : 0.8–5.4) for daughters of mothers of 
40 years as compared to daughters born to mothers of intermediate age (24–30 years). Daughters of mothers of 
20 years, on the other hand, did not appear to have reduced fecundity.
Conclusion The results point to a decreased fecundity of daughters of older mothers, but not of daughters of younger mothers. The inconsistency of the results with respect to the oocytal-maturation hypothesis points to the action of other causal or non-causal mechanisms.
Keywords Maternal age, fertility, infertility, female aetiology, cohort studies, retrospective studies, prenatal exposure, delayed effects, pregnancy in adolescence, multiple pregnancy, pregnancy outcome, fetal death aetiology, family planning
Accepted 1 November 2001