Birth control pills have been available by prescription for more than 60 years and have extensive scientific data to support the safety and efficacy of oral contraceptives. Birth control pills contain the hormones estrogen and progesterone which send signals to the brain to stop producing follicle stimulating hormone (FSH) and luteinizing hormone (LH) which would cause eggs to mature and ovulate in a natural cycle. The effects of these hormones cause the uterine lining to remain thin (not receptive to embryo implantation), and cause cervical mucus to be too hostile of an environment for sperm to swim toward the cervix.

Many women diagnosed with infertility reflect back on the number of years spent preventing pregnancy with birth control and wonder if they somehow caused their infertility with prolonged contraception use. No – there’s no evidence that long-term use of the birth control pill interferes with fertility. Some women experience a disruption in their menstrual cycle for several months after going off the Pill (a condition called post-pill amenorrhea). But this is usually caused by an underlying problem that’s unrelated to the Pill — for example, being significantly underweight, or even being under severe stress.
Contraceptives are a synthetic version of the hormones already produced in the bodies, and ovulation resumes within a few months of discontinuing use of birth control pills in the absence of an underlying infertility condition. Many women will experience normal cycles within one to three months after stopping birth control pills, though it could take six months to one year for a woman to conceive with well-timed intercourse.
In fact, taking the Pill can protect you from diseases — such as ovarian and uterine cancers — that can lead to infertility. Long-term Pill use may improve the symptoms of endometriosis, a condition that can cause abnormal menstrual bleeding and result in infertility. Finally, the Pill has been shown to reduce the incidence of ectopic pregnancy — when a fertilized egg is implanted outside the uterus, typically in one of the fallopian tubes. (Unfortunately, an ectopic pregnancy can’t result in a successful birth.)
Therefore, the suppression of ovulation by the birth control pills is completely reversible, without long standing difficulties in achieving a pregnancy after discontinuing birth control therapy. About 80% of couples do conceive after 12 months of unprotected intercourse.