Objectives: To determine whether prior oral-contraceptive use has a negative effect on the ability of women to conceive in both the short-term and long-term.
Methods: The European Active Surveillance Study on Oral Contraceptives (EURAS-OC) was a controlled, prospective, noninterventional cohort study of 59,510 users of oral contraceptives containing drospirenone or other progestins in clinical practice in seven European countries. In a planned secondary analysis, pregnancy outcomes were investigated in 2,064 participants in EURAS-OC who stopped oral-contraceptive use after study entry because of planned pregnancy. The influence of age, parity, progestin type, ethinylestradiol dose, duration of oral-contraceptive use, and smoking status on the rate of pregnancy was assessed.
Results: Overall, 21.1% (95% confidence interval [CI] 19.4-23.0%) of the past oral-contraceptive users were pregnant one cycle after oral-contraceptive cessation. This rate increased to 79.4% (95% CI 77.6-81.1%) at 1 year (13 cycles). Progestin type, ethinylestradiol dose, duration of oral-contraceptive use, and parity had no major influence on the rate of pregnancy after oral-contraceptive cessation. Up to age 35 years, age had only a minor influence on the rate of pregnancy. Rates of pregnancy were reduced in women older than 35 years and in current smokers.
Conclusion: Previous oral-contraceptive use does not negatively affect initial and 1-year rates of pregnancy after oral-contraceptive cessation. A comparison of these data with data external to this study indicates that the negative effect of aging on fecundity is not amplified by oral-contraceptive use.
Level of evidence: II.