Miscarriage risk by week

It falls — and that downward trend is the real headline. Overall, among people who know they are pregnant, roughly 10–20% of pregnancies end in miscarriage (ACOG puts early pregnancy loss at about 10% of clinically recognized pregnancies), and the great majority of those losses happen in the first trimester, many in the earliest weeks before a scan. From there the remaining risk drops steadily: it is markedly lower once an ultrasound confirms a heartbeat, lower again by 8–9 weeks, into the low single digits by the end of the first trimester, and lower still in the second trimester. Exact per-week percentages vary between studies, so this tool describes the broad pattern rather than a single precise number — but the direction is consistent everywhere: the odds move in a reassuring direction as the weeks go by.

Yes, generally — a confirmed heartbeat is one of the most reassuring early findings, and across separate cohort studies the remaining risk of loss is lower after one is seen than the overall figure suggests. Broadly, that means the low-to-mid teens percent around 6–7 weeks, dropping more clearly into the single digits by around 8 weeks and beyond. It is reassurance, not a guarantee: the risk becomes small, not zero, and the numbers are population averages rather than a statement about your pregnancy. Your provider is the one who follows your dating, symptoms, and scans over time.

No, and this matters: every figure here is a broad average across large groups of pregnancies, not a prediction about yours. Individual risk is shaped by many things this tool doesn't know and can't safely weigh, and a population range simply cannot tell you what will happen for you. Please read the result the way it's meant — as gentle, general context that shows the risk falls as pregnancy progresses — and take any personal questions to your provider or midwife, who can look at your whole picture.

Not necessarily. Light spotting is common in early pregnancy and often turns out to be harmless, and mild cramping can be part of a normally progressing pregnancy. But there's no way to tell from symptoms alone, and it's exactly the kind of thing your provider wants to hear about — so bleeding, cramping, or a sudden loss of pregnancy symptoms is always worth a call. You will not be wasting anyone's time. Seek care urgently — call your provider now or go to an emergency room — for heavy bleeding (soaking a pad an hour), severe or one-sided pain, shoulder-tip pain, fever, or feeling faint, which can signal an ectopic pregnancy or another problem that needs prompt attention.

Almost certainly not, and we want to say this plainly: early pregnancy loss is common, and it is not your fault. Most first-trimester losses happen because of a chromosomal difference in the pregnancy that was present from the very beginning — not because of anything you did or didn't do. Everyday life doesn't cause miscarriage: not working, exercising, having sex, lifting, stress, a fright, or previous birth control. There was very likely nothing you could have done to prevent it. If you're grieving a loss, please be gentle with yourself and lean on your provider — support, and answers about future pregnancies, are things they can help with.

Completely. This tool runs entirely in your browser: the week you choose and the heartbeat answer are used on your own device and are never sent to a server, stored, or shared — close the tab and they're gone. We treat pregnancy data as sensitive by default, so there is no account, no tracking of your inputs, and nothing to delete. What you see is general educational information based on published guidance, not medical advice, a diagnosis, or a prediction about your pregnancy — that belongs with your provider.