Successful spontaneous pregnancies in women older than 45 years

To characterize the reproductive history of women who delivered an infant after a spontaneous pregnancy after the age of 45 years. Observational study. University departments. Two hundred nine women who conceived spontaneously and had their most recent delivery after the age of 45 years. Review of all individual medical charts for a complete history of all pregnancies. Gravidity, parity, and spontaneous abortion (SAB) rate. The mean (±SD) age at last delivery was 45.7 ± 0.9 years (range: 45–49). The mean parity was 9.6 ± 4 children (range: 2–20): 81% of the women were grandmultiparas (≥6 deliveries) and 46% were grand-grandmultiparas (≥11 deliveries). The mean number of SAB was 1.9 ± 1.9 (range: 0–9). Increased parity did not have a protective effect on abortion rate: 12.9% for parity 2–5, 15.6% for parity 6–10, and 21.3% for parity 11–20. Women in the study group differed significantly in their SAB rate from a general population: 11.3% vs. 17.7% at age 39, 13.2% vs. 33.8% at age 44, and 9.1% vs. 33.8% at age 45. Women who conceived at or after 45 years of age were mostly grandmultiparas. Although multiparity in itself did not affect SAB rates, this measure was remarkably low in our exceptionally fertile group as compared with the rates published for a general population. This unique group of grandmultiparous women might possess a genetic propensity that delays the normal rate of ovarian and oocyte senescence.