Does having endometriosis mean I will have a difficult pregnancy and birth?

***Please see below for a research update***

Isn’t endometriosis such a fun disease? It’s hard to read anything about endo without having someone shove the possibility of infertility in your face, and now everyone is talking about pregnancy and birth complications as well! Yay.

Recent media coverage* about women with endometriosis having ‘riskier’ pregnancies and births were all based on only one study. In the world of science we need to build evidence with more than one study before we make a claim. Thankfully some dedicated researchers recently reviewed all of the studies that have looked at pregnancy outcomes in women with endometriosis (you can read it here). This blog post is a brief summary of what they found.

Things to note

1. The findings may not apply to your individual case. Risk of pregnancy and birth complications are likely to be associated with the physical severity and location of one’s endometriosis (e.g. being on or near a reproductive organ), and also the treatment received in the past (e.g. having had major surgery that changed the structure of a reproductive organ).
2. Few studies considered whether women had a condition called adenomyosis in addition to endometriosis. This condition is known to be associated with increased risk of pregnancy and birth complications, and may have affected the findings.
3. Many studies did not consider the effects of using assisted reproductive technology (ART) which carries an increased risk of pregnancy and birth complications. In these studies, it's possible that ART use could be the sole cause of increased risk.

Early pregnancy

Miscarriage is when a pregnancy ends spontaneously, usually in the first three months of pregnancy. It is estimated that 1 in 5 of all women who become pregnant will experience one but little is known about why this happens. The situation is even less clear for women with endometriosis. Studies assessing whether there is an association between having endometriosis and experiencing a miscarriage have been of poor quality. Keeping this in mind, some (but not all) of these studies found that women with endometriosis were slightly more likely to experience a miscarriage than those without the condition. 

Late pregnancy and birth

Seven population-based studies have examined the association between endometriosis and various pregnancy outcomes. The findings of these studies suggest (note the use of the word ‘suggest’ and not ‘show’!) an increased risk of obstetrical haemorrhage, placenta previa and preterm birth for women with endometriosis. An association with pre-eclampsia, low weight babies and caesarean section was less supported. The overall risk for all of these complications is relatively low.

What does all this mean?

There is no high quality evidence to inform women with endometriosis about likely pregnancy and birth complications. The authors of the review note the following points to be considered for the maternity care that women with endometriosis receive:

• It’s important that women receive information about the possibility of complications specific to their individual case, including information about the risks and benefits of vaginal birth and caesarean section.
• Current research does not support the use of additional scans throughout pregnancy, particularly given the inability to anticipate pregnancy and birth complications.
• Women with endometriosis who experience abdominal pain during pregnancy are likely to benefit from care that considers the possibility of endometriosis-associated complications.

I think the main message to take from this is that there is a possibility (not a certainty) of being more at risk of pregnancy and birth complications if you have endometriosis. Given this possibility, it may be of benefit to have a maternity care provider (e.g. midwife, obstetrician) who you trust and are comfortable discussing any of your concerns with. Depending on your individual case, you may also find it beneficial for your maternity care provider to have an open communication channel with your endometriosis specialist so that your health professional team are all on the same page.

I hope you have found this post useful! If you would like to read my other posts on endometriosis and fertility see here, here and here.

Kate xx

*I've chosen not to link to any of the articles as they are misleading and promote a 'fear culture' around birth.

UPDATE: A more recent, higher quality review paper on endometriosis and pregnancy complications has been published. You can read the abstract here. The conclusions of this paper are similar: "Complications of endometriosis during pregnancy are rare and there is no evidence that the disease has a major detrimental effect on pregnancy outcome. Therefore, pregnant women with endometriosis can be reassured on the course of their pregnancies although the physicians should be aware of the potential increased risk of placenta previa. Current evidence does not support any modification of conventional monitoring of pregnancy in patients with endometriosis."

Image via Death to the Stock Photo