Objective: To assess whether pregnancy history can predict the occurrence of a spontaneous ongoing pregnancy in subfertile couples.
Design: Prospective cohort study.
Setting: Thirty fertility centers in the Netherlands.
Patient(s): Subfertile, ovulatory women with at least one patent tube and male partners without severely impaired semen quality.
Intervention(s): Fertility work-up, including a detailed pregnancy history.
Main outcome measure(s): Spontaneous ongoing pregnancy.
Result(s): We included 4445 couples, of whom 793 (18%) had a spontaneous ongoing pregnancy within 1 year of follow-up. Previous live birth and miscarriage in current partnership were both associated with higher fecundity as compared with primary infertility (hazard rate ratios for spontaneous pregnancy [HR] 1.4; 95% CI, 1.2-1.7 and 1.3; 95% CI, 1.0-1.5, respectively). Pregnancies in a woman's previous partnerships did not affect the fecundity of the couple. A pregnancy in a previous partnership of the male partner was associated with lower fecundity (HR 0.76; 95% CI, 0.58-0.99). A previous pregnancy after fertility treatment also was associated with lower fecundity (HR 0.52; 95% CI, 0.30-0.90).
Conclusion(s): Accurate prediction of the future fertility of a couple requires an exact assessment of the fertility history of both partners.