The question After one year my wife (who has endometriosis) got pregnant. We are looking for information on the effect of pregnancy upon endometriosis : is there a risk that endometriosis can grow. .
The answer
effect of a pregnancy upon endometriosis.
Pregnancy makes endometriosis and the endometrium decidualise ie both become less active, and endometriosis cause less pain.
Deep endometriosis can increase slightly in size since decidualised cells are slightly bigger. Only when there is a very big nodule with over 90% occlusion of the bowel, there is some risk of a complete occlusion. Therefore these women should be operated before pregnancy. All the others can be happy to be pregnant and forget temperarily about endometriosis.
After the pregnancy, endometriosis reactivates
Most important is to know that a pregnancy does not increase endometriosis ; it however also does not cure endometriosis.
effect of endometriosis upon the pregnancy : None
Recently (Endometriosis, assisted reproduction technology, and risk of adverse pregnancy outcome Olof Stephansson Helle Kieler, Fredrik Granath1, and Henrik Falconer, Human Reproduction, Vol.24, 2341–2347, 2009) a weak association between endometriosis and delivery before 37 weeks (OR 1.33 ) and increased cesarian section rate (OR 1.43) and preeclampsia (OR 1.13) was reported based upon a retrospective Swedish nationwide study. This article unfortunately has been taken up since to scare women with endometriosis and to advise them to get additional antinatal care.
I consider this as another article with overstretched conclusions and an example that interpretation of research data should be done carefully. First all associations are weak and significant only because of the extremely large sample size. Second this type of retrospective population based study has to be interpreted very careful since the diagnosis of endometriosis was not that clear. Third the increase in preeclamsia is the opposite of another much more solid article, demonstrating a decrease in preeclampsia (Hum Reprod. 2007 Jun;22(6):1725-9. Epub 2007 Apr 23.Endometriosis is associated with a decreased risk of pre-eclampsia. Brosens IA, De Sutter P, Hamerlynck T, Imeraj L, Yao Z, Cloke B, Brosens JJ, Dhont M.) Reality probably is that as is well known, women with a rather long history of infertility, overall are slightly older, and the gynaecologist tend to be more careful and to perform more cesarian sections. In conclusion today I do not see any argument why women with endometriosis should have more antinatal care neither why women with endometriosis should be considered to have an increased risk.
Prof P.R. Koninckx