Almost half of infertility occurs following an initial pregnancy that may have occurred soon after discontinuing contraception. This problem, known as secondary infertility, is often overlooked or downplayed by physicians who see these patients as being fertile and are then reluctant to evaluate or treat. Maternal age and the duration of secondary infertility are critical issues.
We know that women are born with a certain number of eggs – they never make any more eggs the rest of their life. The number and quality of eggs declines as a function time, resulting in a significant decrease in pregnancy rates after age 35, and a drastic decrease after 38. Infertility is defined as a lack of conception after one year of unprotected intercourse. For individuals 35 years or older, most reproductive medicine specialists recommend initiation of a work-up after four to six months of trying. Ultimately, again, remaining egg number and quality are the critical issues.
Evaluation for secondary infertility should be identical to that of primary infertility targeting those issues that are most suspect. Almost 40% of all infertility is male related. Even if a male has fathered a child, semen parameters can change drastically due to a variety of health changes including medical problems, surgeries, traumas, or infections. A semen analysis will evaluate a male’s current fertility status. If there has been a change in male partners, particularly if the new partner has not fathered children, certainly male factor may be the issue. Almost 50% of infertility is female related, primarily ovulatory or anatomic problems. While a female may have a history of regular ovulatory cycles prior to, her ovulatory pattern can change drastically following a pregnancy, especially if there has been a significant weight gain. If prior pregnancy was delivered by cesarean section, adhesion scar formation certainly can occur and be associated with significant tube compromise. Loss of weight will often bring about a return of regular ovulatory cycles.
If there has been a long time between the first pregnancy and initiation of a second pregnancy, certainly the issue of egg quality may be the problem, especially if mom is now over age 35. Strategies to try and improve fertility due to an egg quality issue include superovulation (getting the patient to release multiple eggs) or in vitro fertilization (transferring more than one embryo back to the uterus). If the initial pregnancy was delivered by cesarean section and especially if there was a history of infection, adhesions may be causing a tubal factor. If there was retained placenta following delivery, uterine scarring can occur – hysteroscopy (outpatient surgery – scope is used to look into the uterine cavity) should be considered. With a significant time delay before initiating a second pregnancy, conditions like endometriosis, the growth of endometrial tissue outside the uterine cavity, i.e. in the pelvis, may cause significant anatomic distortion. Likewise, fibroid tumors that may have been small and clinically insignificant prior to pregnancy may now be large and compromising fallopian tubes or the uterine cavity.
In conclusion, secondary infertility is a very common problem. Delaying evaluation and treatment is often associated with severely diminished chances for pregnancy. Secondary infertility should be approached in an aggressive, targeted manner especially in the context of advanced maternal age.