Recurrent Miscarriage: Possible Causes, Tests and the Next Pregnancy

You were told a first miscarriage was common, that it happens to many women. Then a second. Perhaps a third. And this time, reassuring words are no longer enough. If you are reading this after several losses, know this first: recurrent miscarriage is not your fault, and it does not mean you will never have a child.

Repeated miscarriages affect about 1 to 2% of couples, according to the European society of human reproduction (ESHRE). They deserve tests, a listening ear and close follow-up. Here is what doctors look for, what can be treated, and why hope remains well founded. For the signs and management of a miscarriage itself, our article miscarriage: understanding and rebuilding is there for you.

After how many miscarriages do we speak of recurrence?

Professional societies do not all agree:

• two or more pregnancy losses, for the ESHRE (losses before 24 weeks, excluding ectopic and molar pregnancies);
• at least two spontaneous miscarriages in a woman under 40, for French health insurance, which estimates this concerns about 1.5% of women;
• three or more miscarriages, for the British NHS.

This difference is not only about numbers. Lowering the threshold to two allows tests to start earlier, and spares a couple a third loss without answers. If you have had two miscarriages and want to understand why, your request for tests is legitimate.

Why do miscarriages repeat?

In most cases no cause is found, the ESHRE points out. A British hospital guide (Worcestershire) estimates that an explanation is identified in only about a third of couples (36%). For a single miscarriage, the most likely explanation remains a chromosomal abnormality of the embryo, occurring by chance, French health insurance reminds us.

When a cause exists, French health insurance and the ESHRE mainly cite:

Age matters too. According to French health insurance, the risk of miscarriage rises from about 12% at 25 to about 50% at 42. The NHS also cites a father aged 45 or more.

The WHO observes that, in many countries, those around a woman sometimes attribute repeated losses to a spell, the evil eye or her own fault, and that lifestyle-focused advice can make women believe they caused their loss. These explanations wound more than they help. The causes, when found, are medical, and have nothing to do with what you did or did not do.

What tests after repeated miscarriages?

Tests are carried out by a gynaecologist, usually some time after the last miscarriage. The ESHRE guide recommends for all couples:

• a detailed interview on each partner's medical and family history;
• a search for antiphospholipid syndrome by blood test (lupus anticoagulant, anticardiolipin antibodies, sometimes anti-β2GP1). The Worcestershire guide specifies that these tests are done more than six weeks after a miscarriage, and repeated twelve weeks later if positive;
• a thyroid check;
• a pelvic ultrasound to check the shape of the womb.

Depending on the case, the doctor may add chromosomal analysis of the pregnancy tissue, a karyotype of the parents (especially with a family history), or other tests. The ESHRE also lists tests it does not recommend as routine, such as NK cell measurement or HLA typing: if they are offered to you, ask what they will be used for.

What treatments exist?

Treatments depend on the cause, and the ESHRE is clear about what works and what does not.

What has proven its worth, depending on the cause:

• for antiphospholipid syndrome with three or more miscarriages: low-dose aspirin combined with heparin, prescribed and monitored by the doctor;
• for confirmed underactive thyroid: thyroid hormone treatment;
• for a uterine septum: surgery may be offered, preferably within studies;
• for unexplained miscarriages (at least three) with bleeding in a new pregnancy: vaginal progesterone may improve the chances;
• for a genetic abnormality: a genetics consultation.

What the ESHRE advises against or considers unproven: IVF or insemination solely to avoid a miscarriage, corticosteroids, immunoglobulin infusions, Chinese herbal treatments or very high-dose folic acid without an indication. Beware of costly "miracle" treatments.

All doses are set by the doctor. None of these medicines should be taken on the advice of a relative or a forum.

What are the chances of a baby afterwards?

This is the most important question, and the answer is encouraging. The ESHRE stresses that most couples have a better chance of having a baby than of suffering another loss in the next pregnancy. The Worcestershire guide states that more than two thirds of the women concerned go on to have a live birth, and reports a 75% success rate in the next pregnancy for couples followed in a specialist clinic.

These chances depend on age, the number of losses already experienced and any cause. But even when no cause is found, the most likely outcome remains a birth.

The next pregnancy: how to be supported?

A new pregnancy after miscarriages is often lived in anxiety: every trip to the toilet, every cramp is frightening. Ask your gynaecologist for close follow-up from the positive test, with an early first-trimester ultrasound, and a number to call in case of bleeding. Our article on bleeding during pregnancy helps you put things in perspective.

On lifestyle, the ESHRE advises a balanced weight, stopping smoking and no alcohol or drugs, for both partners. The Worcestershire guide adds limiting caffeine.

Taking care of yourself and your couple

Every miscarriage is a loss to be mourned, even a very early one. The WHO reminds us that pregnancy loss remains taboo worldwide, that many women feel shame and guilt, and that this grief deserves to be acknowledged and supported. The two partners may react very differently: one needs to talk, the other stays silent. Neither is wrong.

You do not have to explain anything to the extended family. Choose one or two people you trust. And if sadness, anxiety or guilt set in, a psychologist can help you, alone or as a couple. Our article on living with infertility as a couple offers more ideas for support.