Secondary infertility occurs when a woman who has already carried a child to term is unable to do so a second time. Women who conceive fairly easily, but then repeatedly miscarry, also have secondary infertility. Secondary infertility should not be confused with primary infertility, which means that a woman is unable to become pregnant at all. Women who have been engaging in carefully timed, unprotected intercourse for a year without conception may have secondary infertility and should visit their obstetrician/gynecologist (OB/GYN) or reproductive endocrinologist immediately. Women in their mid-thirties are advised to seek medical attention after six months of trying.
Approximately 20% of women experience secondary infertility at some point in their lifetime. While it is more common than primary infertility, it doesn’t get the same attention that primary infertility does. Many women who are “primaries,” or suffer from primary infertility, resent women who already have a child and are seeking emotional support and fertility treatment to have more children.
Although some women will never know why they are unable to conceive and carry a second child to term, there are some common medical explanations. Endometriosis, body trauma, surgery, complications with the previous delivery and Asherman’s syndrome can all contribute to secondary infertility. Other factors such as a new partner, weight gain, aging and stress can also cause secondary infertility.
Age is one of the primary causes of secondary infertility. Women are born with all the eggs they will ever have to bear children. Fertility peaks from the mid-20s to mid-30s. By 35, there is a marked decrease in fertility. By age 40, the pregnancy rate falls even lower, and by 45, there is only a 6% chance that a woman, with carefully timed, unprotected intercourse, will conceive each cycle.
Over time, there is also a decrease in egg quality, which may explain miscarriage or other problems. Paternal age also plays a role in that the quality of sperm a man produces over his lifetime decreases with age. Some women find that the gap between the first child and the second proves to be too long and their ability to reproduce has declined.
Approximately one-third of infertility cases can be traced to blockages of the Fallopian tubes or abdominal adhesions that can interfere with conception. Ovulation issues such as irregularities, anovulation, defined as the lack of ovulation, or premature ovarian failure may cause secondary infertility. These complications account for about 25% of infertility cases. Age and uterine problems such as endometriosis account for an additional 30% of infertility causes.
To determine the cause of secondary infertility, a specialist will conduct tests to monitor hormonal levels at specific points in a woman's cycle, analyze semen and perform a hysterosalpingogram (HSG). An HSG is a radiological procedure that examines the uterus and Fallopian tubes for tubal occlusion, Asherman’s syndrome or uterus malformations. The doctor will then recommend an infertility treatment that is tailored to the patient's specific type of infertility.
