The web of hormonal interfacing affects the timing of the release of an egg from the ovaries. Women with PCOS often suffer with anovulation, no egg released, or the timing of their ovulation is skewed and unpredictable. Luteal phase defect (LPD), elevated luteinizing hormone levels, and insulin resistance are all possible issues for women with PCOS who are trying to become pregnant or who are experiencing difficulties with their pregnancies.
Luteal Phase Defect and PCOS
The luteal phase of the menstrual cycle is the time between ovulation and the onset of menses - the second half of the period. Luteal phase defect essentially means that the lining of the uterus is not in the right phase of development at the right time and so the implantation of a fertilized egg is prevented, or the embryo can't attach because the lining is too thin.
LPD may be caused by (among other things) an excessive amount of luteinizing hormone (LH) too early in the cycle or an improperly timed LH surge. A situation called LH hypersecretion tends to happen in women with PCOS who have elevated LH during the follicular phase (the first half) of the cycle.
Signals to release the egg from the follicle are sent out too soon and the egg dislodges from the supporting cells prematurely causing a pause in maturation. This interruption is thought to result in abnormal chromosomes in the egg, a condition that increases the risk of miscarriage.
Insulin Resistance is a Known Cause of Miscarriage
Insulin is another hormone that is linked both to miscarriage and to LH. Some women with PCOS have insulin resistance, a situation that requires excessive amounts of insulin to control blood sugar levels. High insulin levels stimulate production of LH and testosterone, both of which are linked to poorer egg quality and ultimately to miscarriage. Insulin resistance does have a link to recurrent miscarriage.
When these factors are considered, it is possible to see how the risk for a woman with PCOS can be higher when it comes to conceiving a pregnancy and carrying it to term.
Learn more about the causes of miscarriage on our site.