Recurrent miscarriage is three or more early losses, affecting about 1 in 100 couples, and over half of investigations find no cause.
When causes do surface, the list is specific. Chromosomal abnormalities in the embryo cause most individual miscarriages; a balanced translocation in either parent can make them repeat. Antiphospholipid syndrome, an immune clotting disorder, is the most important treatable cause and responds to blood thinners in pregnancy. Uterine factors like a septum, fibroids, or scarring can block implantation. Thyroid disease and poorly controlled diabetes play roles. Age is a major driver, with risk rising steeply after 35 as chromosomal errors in eggs increase. Testing usually begins after three losses and covers clotting antibodies, thyroid and hormones, parental chromosomes, and uterine imaging. The prognosis is better than the experience feels: most couples with recurrent loss eventually have a baby, and finding a treatable cause like APS shifts the odds further in your favor.
What to do
Common questions
What causes recurrent miscarriage?
Recurrent miscarriage means three or more early pregnancy losses in a row, and it affects about 1 in 100 couples trying for a baby. The hardest fact first: in more than half of cases, every test comes back normal and no cause is found. When causes are found, they fall into a few buckets. Chromosomal problems in the embryo cause most single miscarriages, and a parental chromosome rearrangement (a balanced translocation) can make losses repeat. Antiphospholipid syndrome, a blood-clotting immune condition, is the most important treatable cause, and it responds to blood-thinning treatment in pregnancy. Uterine shape problems (a septum, fibroids, scarring) can interfere with implantation. Hormonal and metabolic issues, including thyroid disease and poorly controlled diabetes, contribute. And age matters more than most people realize: miscarriage risk climbs steeply after 35 because chromosomal abnormalities get more common. Investigation typically starts after three early losses (two if you are older or there are other circumstances) and includes blood tests for clotting and hormones, both partners' chromosomes, and a uterus scan. The hopeful number: even after repeated losses, the majority of couples go on to have a successful pregnancy, especially when a treatable cause is found.