How can PCOS affect fertility, and which treatments are most effective?

In our previous post about PCOS, we talked about its common symptoms and diagnostic criteria. One of those symptoms are infrequent or missing periods and irregular or missing ovulation, which interfere with the ability to conceive. According to the CDC, 16% of diagnoses in patients with fertility challenges are due to issues with ovulation. Below we’ve summarized the literature on PCOS and fertility treatments to give you an overview of how issues with ovulation can be overcome most effectively.

The first treatment step for fertility patients with PCOS is usually to take a drug that induces ovulation, so that an egg is released from its follicle and can be fertilized. There are multiple drugs that help induce ovulation, but recent studies have found one to be more effective than the other: Letrozole (Femara) seems to have much better results than Clomidphene Citrate (Clomid). Of 149 participants in one double-blind clinical trial, women receiving letrozole had a significantly higher cumulative pregnancy rate at 63% than those taking Clomid (43%). Women on Letrozole also took fewer treatment cycles to get pregnant – on average 4 cycles instead of 6 with Clomid. PCOS patients with a BMI <30 in this study had even higher pregnancy rates of 69% with Femara vs. 47% with Clomid.

Fertility patients with PCOS also often undergo intrauterine artificial insemination (IUI) in addition to taking medication that induces ovulation. Interestingly, there does not seem to be a significant improvement in live birth rates in patients who undergo IUI with Clomid versus those who just take Clomid by itself. Unfortunately, there isn’t yet a study on Letrozole with IUI.

If PCOS patients use IUI, pregnancy rates are higher if they also take gonadotropins to stimulate the ovaries, particularly if they’re taken in addition to ovulation-inducing drugs such as Letrozole. However, stimulating the ovaries also tends to increase the number of follicles that mature and are fertilized during IUI. This can triple the likelihood of having twins or triplets compared to using only ovulation-inducing drugs without gonadotropins.

In-vitro fertilization (IVF) is typically the most effective (but also most expensive and least likely to be covered) fertility treatment, and there are some interesting findings for PCOS patients: Women with PCOS seem to have significantly higher birth rates and a lower risk of ovarian hyperstimulation if they undergo IVF, then freeze an embryo, and implant this embryo at a later time than if they implant it right after they have undergone treatment (i.e., a frozen vs. fresh transfer). In a study of 1,500 women published in the New England Journal of Medicine, researchers found that women who had implanted previously frozen embryos had a higher chance of live birth and lower rate of pregnancy loss than those whose embryos were not frozen prior to implantation. The researchers suggest that allowing the ovaries to recover and certain hormone levels to return to more favorable levels while an embryo is frozen could help improve later pregnancy outcomes.

In our next post, we’ll discuss how to deal with and improve PCOS symptoms on an everyday basis.

 

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