Having appendix out doesn’t reduce fertility

Medical experts have until now believed that the surgical trauma of an appendectomy operation can affect a woman’s fertility, leaving scar tissue sticking to the fallopian tubes and obstructing an egg on its way to the uterus.

But research led by Mr Sami Shimi, a surgeon from Dundee University, has rejected this theory – and has suggested for the first time a possible link between appendectomies and an increased subsequent pregnancy rate.

Mr Shimi said he had been amazed by the results of the research. However, he stressed that further work would be needed to establish whether the findings could pave the way to a potential new fertility treatment.

He said: “Clearly, for women who used to fear having an appendectomy because of its effects on pregnancy, that fear is unfounded. Previous studies are flawed.

“But we are not at the stage of saying that this has opened up the possibility of some form of fertility treatment.

“We are making it clear that, at this stage, women should not present to have their appendix removed to increase their chances of fertility. We do not have any evidence to suggest that is in fact the correct course.

“But, without doubt, these surprising results open up the need for further research.”

Mr Shimi said his initial research had focused on data from Tayside. “The data showed that girls in the area who had had an appendectomy became pregnant more frequently in comparison to a control group of women who did not have their appendix removed,” he said. “I thought at first that we had done something wrong and that our findings couldn’t be right – maybe it was just a quirk of Tayside.”

Mr Shimi and his colleagues then decided to embark on a far larger study, using one of the world’s largest digital repositories of medical records, the UK’s General Practice Research Database.

They found that out of more than 76,000 women who had undergone an appendectomy, 39 per cent had a first pregnancy in the decade following the procedure.

For those who had not had their appendix removed, the rate was only 28 per cent.

The fertility gap remained after accounting for age, birth control use, number of previous hospitalisations and other factors.

“I was completely surprised,” he said. “We thought at first we had done something wrong again.

“We sat on the results, but every way we checked it, there was no mistake and same result applied – the women who have not had an appendectomy were less fertile or had fewer subsequent pregnancies than women who had had an appendectomy.”

He added: “There are two schools of thought about why that has happened. One is behavioural and the second that there may be something biological about these women. Does the appendix secrete substances that might inhibit the sperm from impregnating the ovum?”

Further studies were needed to determine whether there was something “unique” about women who required appendectomies, Mr Shimi said.

The results of the study are published in the latest issue of the journal of Fertility and Sterility.