Miscarriage risk by week: what the figures say and where to find support in Singapore

Miscarriage risk is highest in the first weeks of pregnancy and falls quickly week by week. KKH says miscarriages in the first trimester, before 12 weeks, happen in up to one in five pregnancies, and most miscarriages happen in that window. If it happens to you, our guide to miscarriage leave in Singapore explains the leave you can take. Once a scan shows your baby's heartbeat, the odds improve fast: in one hospital study of women with no symptoms, the risk of a later miscarriage was 9.4% at 6 weeks, 4.2% at 7 weeks, 1.5% at 8 weeks and 0.5% at 9 weeks. About half of early miscarriages come from a problem with the baby's chromosomes, and KKH is clear that food, stress, work, exercise, travel and sex don't cause them. If you're reading this anxious or after a loss, below are the figures in plain terms, the signs that need a doctor, and where to get help and support in Singapore.

Miscarriage risk by week after a heartbeat is seen

The clearest week-by-week figures come from a study of 696 pregnant women at a large Australian hospital, published in Obstetrics and Gynecology in 2008. Each woman had no bleeding or pain and had a scan at her first antenatal visit showing her baby's heartbeat. The researchers then counted how many went on to miscarry, grouped by the week of that visit:

The 10-week figure is a touch higher than 9 weeks because each group was small; the trend still fell sharply week by week. The authors concluded that for women without symptoms, the chance of a pregnancy continuing past 20 weeks after a normal scan from 8 weeks on is very good. Our week-by-week guides, such as 6 weeks pregnant, 8 weeks pregnant and 12 weeks pregnant, cover what each scan shows. Our due date calculator tells you which week you're in.

Across the whole pregnancy

Counting all pregnancies, including those before a scan, the figures are higher because the earliest weeks carry the most risk:

• KKH: up to one in five pregnancies end in miscarriage before 12 weeks. Another KKH page puts it at one in four to six pregnancies in total.
• A 2021 review in The Lancet pooled studies worldwide and found 15.3% of recognised pregnancies end in miscarriage.
• A 2012 systematic review found the weekly rate stays above 20 per 1,000 women in every week before week 13, falls below 10 per 1,000 by week 14 and drops further to week 20. Its estimate of the total risk from week 5 to week 20 was 11% to 22%.

In Singapore, SingHealth defines miscarriage as the loss of a pregnancy in the first 28 weeks, and a loss after 12 weeks is called a late miscarriage. Late miscarriages are much less common than early ones.

What changes the risk

Age matters most. KKH puts the risk of miscarriage at one in five (20%) up to age 35. Over 40, it's one in two (50%). A large Norwegian study in the BMJ found a similar pattern. The risk was lowest at 25 to 29 (10%), climbed after 30 and reached 53% at 45 and over.

KKH also lists these as raising the risk:

• Poorly controlled diabetes or thyroid problems, infections, or autoimmune conditions such as lupus
• An abnormally shaped womb
• Smoking, heavy drinking, and being very underweight or overweight
• A previous miscarriage, an older partner (over 40) and a low progesterone level in early pregnancy, from a study by KKH and Duke-NUS
• Carrying twins or more

Caffeine is worth cutting back on. KKH's doctors link high caffeine intake with miscarriage and advise avoiding it in the first trimester, then no more than one cup of coffee or tea a day.

What doesn't cause a miscarriage

Many women blame themselves, and they shouldn't. KKH's miscarriage page says a miscarriage is not caused by eating any specific food, stress, strenuous activity, working, travelling, exercise or sex. In most cases there's no identifiable cause, and about half of early miscarriages are linked to the baby's chromosomes, which KKH says usually happens by chance. Bed rest and hospital stays haven't been shown to lower the risk, and KKH says progesterone may not prevent an early miscarriage.

Signs to watch for, and where to go

KKH lists spotting or bleeding, fluid or tissue passing from the vagina, tummy pain or cramping, and a dull pain in the lower back as the common signs. Any one of these on its own doesn't mean you're miscarrying (our guide to bleeding in early pregnancy explains what the colour and amount tell you): many women bleed or cramp in the first trimester and go on to a healthy pregnancy. When a scan shows the baby's heartbeat despite bleeding, doctors call it a threatened miscarriage, and KKH says most women go on to have a healthy pregnancy.

If you have a rhesus negative blood type, such as O negative, KKH may offer an anti-D injection after a miscarriage to protect future pregnancies. Our guide to prenatal check-ups and scans explains your early visits.

Support after a miscarriage in Singapore

KKH says every couple grieves differently: some feel low for a short time, others take much longer. Lean on friends and family, and tell your doctor if you need more help. These are the services named on KKH's and HealthHub's pages:

• KKH medical social workers: 6394 1028 or 6394 1029, Monday to Friday 8.30am to 5.30pm and Saturday 8.30am to 1pm. Your KKH doctor can also refer you to the hospital's mental wellness team.
• KKH appointments for follow-up: 6294 4050, same hours.
• Health Promotion Board hotline for health questions: 1800 223 1313, weekdays 8am to 6pm.
• Belle, the Beyond the Label helpbot on HealthHub, for stress or anxiety and contacts for counselling.
• If you've had three or more miscarriages, ask about KKH's recurrent pregnancy loss service at KKIVF, which can also refer you to social workers and psychologists.

When you're ready to try again, KKH says your next period usually comes in four to six weeks, and you can try as soon as you both feel physically and emotionally ready. Most miscarriages are a one-off, and the chance of a successful next pregnancy is good. KKH recommends at least 400mcg of folic acid a day for three months before you conceive. Our guide to trying again after a miscarriage covers timing, the odds and support, and trying to conceive covers the rest.

Frequently asked questions

When does the risk of miscarriage drop?

It falls week by week through the first trimester. After a scan shows a heartbeat, one study found the risk was 1.5% at 8 weeks and 0.5% at 9 weeks for women without symptoms. By week 14 the weekly rate is far lower than in the early weeks.

What are the riskiest weeks for a miscarriage?

The weeks before 12 weeks. KKH says most miscarriages happen in the first trimester, and the weekly rate is highest before week 13.

Does seeing a heartbeat mean I won't miscarry?

It lowers the risk a lot, though not to zero. In the 2008 study, the risk after a heartbeat was seen ranged from 9.4% at 6 weeks to 0.5% at 9 weeks.

Can stress or work cause a miscarriage?

KKH's miscarriage page says a miscarriage isn't caused by stress, working, strenuous activity, exercise, travel or sex. If you've had repeated miscarriages and a stressful job, KKH doctors suggest a break from work in the first 12 weeks.

Will I miscarry again?

Usually not. KKH says most miscarriages are a one-off and there's a good chance of a successful pregnancy. After three or more, it advises specialist care.