Natural conception after age 45 in Bedouin women, a uniquely fertile population

Purpose: Women conceiving naturally and delivering after age 45 are an exceptionally fertile population that may serve as a model to identify factors associated with delayed reproductive aging. This work studies this phenomenon in Bedouin women. Methods: The study is an observational retrospective analysis of all Bedouin women who conceived spontaneously and had their latest delivery after the age of 45 years, during the years 1995-2000 at the participating medical center. Complete histories of the outcomes of all pregnancies were collected. Results: 133 of 34,519 (0.38%) Bedouin women gave birth after the age of 45 years. The mean maternal age at last delivery was 46±1.4 years (range: 45-52), and the mean parity was 11.6±2.9 children (range: 3-18). 96% were grandmultiparous (≥6 deliveries). The mean spontaneous abortion rate (6.6%) was not affected by increased parity and was significantly lower than in the general population: 12.4% vs.17.7% at age 39, 5% vs. 33.8% (p < 0.001) at age 44 and 1.8% vs. 53.2% (p < 0.001) at age 45. Conclusions: This unique group of Bedouin women may have a genetic predisposition to delayed ovarian and oocyte aging.