appendectomy tonsillectomy increase fertility

File this under just plain weird, but recent research has found that pregnancy rates were significantly higher among women who had had an appendectomy (54.4 percent), tonsillectomy (53.4 percent) or both (59.7 percent) than among women who had had neither surgery (43.7 percent). Furthermore, those who had either surgery or both got pregnant quicker when they started trying.

Say what???

Background on the Study

This population-based study examined the medical records of more than half a million women over 25 years. Researchers looked at 54,675 subjects who had an appendectomy-only (average age at surgery was 16.2 ± 7.8 years), 112,607 women who had an tonsillectomy-only (average age was 10.8 ± 7.2 years), and 10,340 women who had both an appendectomy and tonsillectomy. Researchers matched these women with a woman of the exact age in the general population who had neither an appendectomy or tonsillectomy, and both women were followed over time.

Why Appendectomy & Tonsillectomy Increase Fertility

The increase is pregnancy rates and time to pregnancy was significant for women who had previously had an appendectomy or tonsillectomy. Researchers do not know exactly why an appendectomy or tonsillectomy would increase fertility but they have a few hypotheses.

A previous study had found the connection between appendectomies and increased subsequent pregnancy rates and time to pregnancy, so researchers thought it might have something to do with the disruption in the pelvic area after surgery. The finding in this study of the correlation with tonsillectomies, which occur in the throat, makes it unlikely that a disruption in the pelvic area is responsible.

One possible explanation is that this study inadvertently selected women with more frequent sexual intercourse due to higher libido, a more liberal attitude toward sex, or unknown factors. The data showed that the women who had previous appendectomies and tonsillectomies had a higher rate of chlamydial infections, pelvic inflammatory disease, and previous pregnancies, all of which could indicate increased sexual activity.

It is possible that episodes of pelvic inflammatory disease resulting from liberal sexual activity or inflammatory bowel disease necessitated hospital admission with lower abdominal pain which eventually lead to removal of the appendix. … By the same reasoning, a similar group of women developed recurrent throat infections as a result of intimate contact with men, which led to recurrent episodes of tonsillitis necessitating surgery.

An intriguing possible explanation revolves around the impact of appendectomies and tonsillectomies on a woman’s immune system. Both the appendix and the tonsils are part of the lymphatic/immune system. Removal of the appendix and/or tonsils can alter the immune system, and the effect is more pronounced when both the appendix and tonsils are removed. For a successful pregnancy to occur the woman’s immune system must accept a “foreign body” (the embryo/fetus). Too high of an immune response could impair fertility, and a minor reduction in immunity could possibly increase fertility.

However, if a reduction in immune response was the cause of increased fertility, the researchers would expect to see not only an increase in pregnancy, but also a reduction in miscarriages in the women who had the previous surgeries. Although the data may not be complete, researchers saw an increase in miscarriages, thus giving less credence to the immune response explanation.

Another possible explanation is a general reduction in inflammation in a woman’s body after the removal of the appendix and/or tonsils. A degree of systemic or uterine inflammation is essential for normal implantation and pregnancy, however, too much inflammation throughout the body might hurt the embryo or impair implantation. The appendix and tonsils are part of the lymph system and are susceptible to inflammation. “Surgical removal may reduce the risk of attacks of inflammation related to these organs, which could result in improved well-being of young women, including a more permissible uterine-tubal-ovarian environment for pregnancy.”

Why Should We Care?

Appendectomies and tonsillectomies are on the decline because of current medical practice, but understanding the mechanism of how these organs impact fertility could improve our understanding of fertility and infertility in general and improve the treatment of infertility.