Miscarriage and PCOS - Is There Increased Risk?
The evidence tends to be conflicting on the subject of miscarriage risk in women with PCOS. A large number of studies have been done and each study has its strengths and weaknesses. It has been confirmed that there is a link between PCOS and infertility, and there are some indications that certain aspects of PCOS can influence miscarriage.
PCOS, What it Is and What it Does
PCOS is a condition in which a woman's ovaries and in some cases, the adrenal glands, produce more androgens (male hormones) than normal. It is the most common cause of female infertility related to anovulation - that is the absence of ovulation. The fact is that most women don't know they have PCOS until they try to conceive and are unsuccessful. Menstrual and ovulatory irregularities that can lead to infertility are common in women with PCOS. Most women with infertility related to PCOS can be treated and do become pregnant. However, some women with infertility related to PCOS do not respond to treatment and do not become pregnant.
Does PCOS Cause Miscarriage?
Although it is reported that some studies indicate the incidence of miscarriage in women with PCOS is as high as 45%, there is conflicting evidence. A study completed in 2003 by Schieve and colleagues who analyzed 62,228 pregnancies achieved with ART determined that the overall miscarriage rate among women with PCOS was 14.7%. This risk was no different from the average miscarriage rate of all the other groups. In this case, those who conceived did so through assisted reproduction techniques, which carry an increased number of incidents of miscarriage than normal conception in healthy women.
It is important to remember that the estimates of incidence of miscarriage vary since many women who miscarry do so without even knowing they were pregnant. It is estimated that one in four pregnancies (25%) end in miscarriage, most of them during the first trimester of pregnancy.
The Hormonal Connections
Some reasons for miscarriage that may apply more to women with PCOS revolve around hormones, since PCOS wreaks havoc with a woman's hormones. Women with hormonal irregularities may find it more difficult to conceive and, when they do it seems they are more likely to miscarry. One of the dominant features of PCOS is multiple hormonal imbalances with some hormone levels being very high while others are very low.