Why am I unable to get pregnant?

Note on the name: in May 2026, polycystic ovary syndrome (PCOS) was formally renamed polyendocrine metabolic ovarian syndrome (PMOS), following a global consensus process. The old name was inaccurate — the condition affects multiple hormone and metabolic systems, not just the ovaries, and "polycystic" wrongly implies ovarian cysts. Nothing about the condition, its diagnosis or its treatment has changed. Both names will be used side by side for the next few years, and we use PCOS below since that is the term most people know.

Difficulty conceiving is far more common than most people realise. The World Health Organization has estimated that around one in six people worldwide are affected by infertility at some point in their lives — so if this is where you are, you are in very large company. The cause can lie with either partner, or both, or remain unexplained after full testing. Common factors include ovulation problems (PCOS, thyroid disorders, premature ovarian insufficiency, raised prolactin), blocked or damaged fallopian tubes, endometriosis, uterine abnormalities, and male factor — which means sperm count, movement or shape. Two things worth knowing. First, male factor is involved in a substantial proportion of cases, yet it is still frequently overlooked. A semen analysis is quick, inexpensive and non-invasive, and should be among the first tests, not a later one. Second, "unexplained" is a real and reasonably common outcome — it means standard tests found nothing, not that nothing is wrong or that nothing can be done. Please see a fertility specialist if you have been trying for 12 months, or 6 months if you are 35 or over. Go sooner if your periods are irregular or absent, you have known endometriosis or PCOS, you have had pelvic surgery or infection, or either of you has a known fertility concern. Both partners should be assessed together from the start.