Polycystic ovarian syndrome (PCOS) and fertility

Women with PCOS frequently present to their GP with fertility issues. PCOS is the most common cause of anovulation (failure of the ovary to produce an egg). Some women with PCOS may require medical treatment in order to conceive, but in many cases a degree of weight loss could be sufficient to restore regular ovulation.

Why might women with PCOS struggle to get pregnant?

Around 70% of women with PCOS suffer from anovulation. This may manifest as irregular or absent periods (oligo- or amenorrhoea), as well as with difficulties getting pregnant. Women with PCOS have lots of small follicles (sacks of fluid) in their ovaries which contain eggs at an early stage of their development. These follicles fail to develop in a way that would allow egg release. The reasons behind this are complex, but are usually driven by issues such as increased androgens (hormones like testosterone), high insulin levels, and excess weight.

Can the chances of conceiving be improved?

Yes. One of the most effective strategies for patients with irregular periods is to lose weight (see leaflet on PCOS and body weight). People with overweight or obesity are far more likely to have menstrual disturbance and hence fertility issues. Weight loss achieved through lifestyle changes or via medical or surgical treatments greatly improves the likelihood of conceiving without requiring any further medical treatment. If you have excess weight, then losing 5-10% of total body weight can significantly improve the chance of spontaneous ovulation. If possible, you should also consider trying to conceive before the age of 35 to maximise your chances of successful pregnancy, as there is a natural and gradual decline in egg quality after this age.

What tests may be needed to investigate fertility concerns or problems?

A number of blood tests arranged by your doctor will help to confirm an underlying diagnosis of PCOS. If your periods are regular, we will need to obtain a blood test on Day 21 of your cycle, measuring progesterone levels to determine if an egg has been released. We may also need to arrange a test to examine your fallopian tubes. This is called a hysterosalpingogram, and it tells us whether any blockages are present in the tubes leading from the ovary which may result in obstruction to release of an egg. In certain cases, we may want our radiologist to visualise the ovaries and uterus with an ultrasound. If your partner is male, they will also need to provide a semen sample for analysis and this should be arranged via their GP.

What treatments are available for problems with ovulation?

If conception does not occur after weight loss, or if your body weight is already in the healthy range, a number of medications may be prescribed by your doctor to increase the likelihood of ovulation and hence conception. Medications such as clomiphene or letrozole are taken for 5 consecutive days at the start of the menstrual cycle, usually for a total of 6 consecutive months. These drugs work by increasing levels of ovarian-stimulating hormones from your master hormone gland, the pituitary. These medications are cheap, safe, and effective and have been in use for many years. The risk of multiple pregnancy is in the region of 8-10% with these drugs.

Depending on your clinical circumstances, your doctor may also prescribe a drug called metformin alongside clomiphene or letrozole. This medication is commonly used to treat type 2 diabetes, and works by lowering insulin levels. The net effect of this in PCOS is that it increases the likelihood of ovulation. Other beneficial effects may include a small degree of weight loss. 

In the event that clomiphene, letrozole, or metformin combined with lifestyle measures do not result in ovulation, we may sometimes refer you to our Gynaecology colleagues to discuss a procedure called laparoscopic ovarian diathermy (LOD), previously called laparoscopic ovarian drilling. Your suitability for this will depend on factors such as your age. This procedure involves a laparoscopy (telescope inserted through the belly button) under general anaesthesia, and is performed as a day case procedure. The aim of the procedure is to induce ovulation and it has been shown to be often effective in this situation.

What are the next steps if these interventions are unsuccessful?

Should ovulation or conception not occur in response to the above treatments, the next step would be to refer you to a fertility unit to discuss Assisted Conception techniques. You may be suitable for ovulation induction or in-vitro fertilisation (IVF).  Depending on a range of factors, you may be suitable for a cycle of Assisted Conception, although this may need to be self-funded. Typically, the factors that determine your suitability for assisted conception include your age, weight and smoking status.

Ovulation induction is a treatment which involves having injections of pituitary gland hormones called gonadotropins. These injections will stimulate ovulation and are administered at different times during your menstrual cycle. Ultrasound scanning will be used by the Fertility team to track your response to the injections and to determine when ovulation is about to occur. If you are not having in vitro fertilisation (IVF) alongside ovulation induction, you will be advised about the optimal timing of intercourse in the days around ovulation.

Whether ovulation induction is combined with IVF will depend on other factors such as your age and your partner’s sperm quality. If you are advised to have IVF, an egg collection will be performed under general anaesthetic, and fertilised outside the womb (in vitro) with your partner’s sperm. Usually one good quality embryo is chosen to be transferred into the uterus and any other good quality embryos can be frozen for future use. Success rates vary from 20-40% depending on your age and general health.

This information leaflet has been co-authored by:
Dr. Michael O’Reilly (Consultant Endocrinologist, Beaumont Hospital)
Dr. Conor Harrity (Consultant Gynaecologist, Beaumont Hospital)
Ms. Maureen Busby (CEO and Founder, PCOS Vitality patient support group https://www.pcosvitality.com/what-is-pcos)

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