What is the most common cause of female infertility?

The most common cause of female infertility is indeed polycystic ovarian syndrome (PCOS). This condition affects the hormonal balance in women and can lead to irregular ovulation or anovulation, which significantly impacts fertility. PCOS is characterized by a triad of symptoms, including irregular menstrual cycles, signs of hyperandrogenism (such as hirsutism), and polycystic ovaries observed on ultrasound. The prevalence of PCOS makes it the leading cause of infertility in women due to the widespread impact it has on reproductive health.

While conditions like fibroids, endometriosis, and pelvic inflammatory disease can certainly contribute to infertility, they are not as commonly encountered as PCOS. Fibroids can interfere with implantation and pregnancy maintenance but are often asymptomatic and do not affect all women. Endometriosis, which involves the growth of endometrial tissue outside the uterus, can cause pain and infertility but occurs in a smaller percentage of women compared to PCOS. Pelvic inflammatory disease may lead to scarring and fertility issues, yet it often arises from infections that can vary in prevalence.

Overall, while other options play a role in infertility, the scale and consequences of PCOS make it the most common cause encountered in clinical practice.