DUNDEE, Scotland, Aug. 3 (UPI) -- Although doctors have thought women's fertility is damaged by undergoing an appendectomy, a study of half a million women in the United Kingdom suggest that is not true.
Women with their appendix removed appear to be more likely to get pregnant, as are women who have their tonsils removed, report researchers at the University of Dundee and University College London who say they were somewhat surprised by the results.
A smaller study by the researchers suggested the higher rates of pregnancy for women who have had either or both procedures, leading to the second, larger review of medical data.
Unsure of why the procedures appear to make it more likely women will get pregnant, researchers at the two universities told BBC News the explanation could be behavioral, or may be tied to the removal of inflamed organs.
"This research does not mean that removing a normal appendix directly increases fertility," Sami Shimi, a clinical senior lecturer at the University of Dundee, said in a press release. "It does however mean that young women who need to have their appendix removed can do so without fear of the risk on future fertility."
For the study, published in the journal Fertility and Sterility, researchers reviewed medical data for 54,675 women who had an appendectomy, 112,607 who had a tonsillectomy, 10,340 who had both and 355,244 who had neither procedure in the United Kingdom between 1987 and 2012.
Of the women, 54.4 percent of appendectomy patients, 53.4 percent of tonsillectomy patients and 59.7 percent of patients undergoing both procedures got pregnant, compared to 43.7 percent of women who had not undergone the procedures.
The researchers say the results show that should women need either surgery, they'll most likely be able to get pregnant later in life.
"This research is of paramount interest because appendectomy and tonsillectomy are very common surgical operations, experienced by tens of thousands of people in the UK alone," said Dr. Li Wei, a researcher at the School of Pharmacy at University College London. "Although a biological cause is possible, we believe that the cause is more likely to be behavioral. We are pursuing both hypotheses with further research."