Miscarriage is the most common complication of pregnancy and one of the least discussed. About 1 in 5 confirmed pregnancies ends in loss, and the true rate — including pregnancies that end before anyone knew they had started — is meaningfully higher. Most people who miscarry walk through it with very little public language for what is happening, and almost all of them ask the same question at some point: did I do something wrong. The answer is almost always no.
The biology of early pregnancy loss is well understood now. The overwhelming majority of first-trimester miscarriages are caused by chromosomal errors in the embryo. They are not caused by lifting a box, having sex, eating soft cheese, getting on a plane, or having a stressful week. For more on pregnancy and parenting, visit Healthbooq. For a broader overview, see our complete guide to parenting.
How Common Miscarriage Is
Around 15 to 20 percent of confirmed pregnancies end in miscarriage. Most losses happen in the first trimester (before 12 weeks), and the risk drops sharply once a heartbeat is seen on ultrasound at 6 to 7 weeks. The NHS estimates roughly 250,000 miscarriages occur in the UK each year.
Risk rises with age, mostly because chromosomal errors in eggs become more common. Approximate figures by maternal age:
- 25 to 29: about 13 percent
- 35 to 39: about 20 percent
- 40 to 44: about 40 percent
Why Miscarriage Happens
In 60 to 70 percent of first-trimester losses, the cause is a chromosomal abnormality in the embryo — most often trisomy, three copies of a chromosome instead of two. This is a random error during cell division, not an inherited condition. The embryo cannot develop, and the pregnancy ends. Investigation is usually not done after a single first-trimester miscarriage because there is rarely anything actionable to find.
Less common causes include uterine structural abnormalities (such as a uterine septum), antiphospholipid syndrome (an autoimmune condition that affects placentation), uncontrolled thyroid disease, and rare infections.
Types of Miscarriage
Early pregnancy assessment units (EPAUs) use specific terms for what they see on the scan and the exam. The labels matter because they determine what comes next.
- Threatened miscarriage: bleeding in early pregnancy with a viable embryo on ultrasound. Many do not progress to loss.
- Inevitable miscarriage: bleeding with cervical dilation. The miscarriage is in progress and will continue.
- Incomplete miscarriage: some, but not all, pregnancy tissue has passed.
- Missed (or silent) miscarriage: the embryo has died but no bleeding has occurred. Often discovered at a routine scan.
- Blighted ovum (anembryonic pregnancy): a gestational sac with no visible embryo, caused by very early embryonic failure.
Management Options
Once a miscarriage is diagnosed, there are three routes. None is medically superior for an uncomplicated loss; the choice is yours, guided by your circumstances.
Expectant management — waiting for it to complete on its own. Bleeding and cramping can be heavy and last from a few days to several weeks. Around 50 to 80 percent of incomplete miscarriages resolve fully within 2 to 4 weeks this way. Reasonable for someone who is medically stable and would rather not intervene.
Medical management — misoprostol. A prostaglandin that triggers uterine contractions and tissue expulsion, given vaginally or under the tongue. Effective in around 80 percent of cases, usually within hours. Cramping is often significant — the same intensity as labour for some people. Pain relief and a clear plan for what to do if bleeding gets very heavy are essential.
Surgical management — ERPC (evacuation of retained products of conception). Now usually a 10 to 20 minute outpatient procedure under local anaesthesia, sometimes general. Recommended when there is infection, heavy bleeding, or when the other routes have not worked. Recovery is fast for most people.
If you cannot decide, the EPAU team can talk through the trade-offs. Each option has different demands on time, pain, and emotional pacing.
The Emotional Impact
Grief after miscarriage does not scale with how many weeks the pregnancy lasted. A loss at 6 weeks can hit harder than one at 11. Some people grieve for months. Others feel mostly relief, or a pragmatic sadness, or a confusing mix that changes by the day. All of it is normal.
Partners grieve too, often without the same social acknowledgement. Friends and family who did not know about the pregnancy cannot offer condolences for it, which leaves many people grieving in private and feeling more alone than they expected.
The Tommy's pregnancy charity and Siobhan Quenby's group at the University of Warwick have documented how thin the emotional support around miscarriage often is. The Miscarriage Association runs a helpline and peer support — including for partners — and is one of the most accessible places to start.
If grief, low mood, or intrusive thoughts persist for more than a few weeks, or you find yourself unable to function, talk to your GP or midwife. Postpartum-style depression after pregnancy loss is real and treatable.
Recurrent Miscarriage
Recurrent miscarriage is defined as three or more consecutive losses and affects about 1 percent of couples. It warrants specialist investigation. Causes that can be found and acted on include:
- Chromosomal abnormalities in one or both parents
- Antiphospholipid syndrome (treatable with low-dose aspirin and heparin in pregnancy)
- Uterine abnormalities such as a septum
- Thrombophilias
In about half of recurrent miscarriage cases, no cause is identified despite full work-up. This is genuinely frustrating, but the prognosis is still often good. Specialist clinics — Tommy's National Centre for Miscarriage Research, led by Siobhan Quenby, is the UK's leading example — are associated with better outcomes, partly through close surveillance and support in the next pregnancy.
Future Pregnancy
The numbers, after a single miscarriage, are reassuring. They do not feel that way in the first weeks, and that is fine. Approximate chance of a successful next pregnancy:
- After 1 miscarriage: about 85 percent
- After 2: about 75 percent
- After 3: about 65 percent
There is no fixed evidence-based wait. Most guidance is to wait until bleeding has stopped and you feel ready. A large UK study (Bhattacharya et al., BMJ 2010) found that conceiving within 6 months of a miscarriage was associated with better outcomes, not worse, contradicting older advice to wait longer. If you want to try again soon, that is reasonable. If you need more time, that is also reasonable. The right window is the one that fits your body and your head.
Key Takeaways
About 1 in 5 confirmed pregnancies in the UK ends in miscarriage — roughly 250,000 a year. Most happen in the first trimester and are caused by random chromosomal errors in the embryo, not by anything the pregnant person did, ate, or felt. Three management routes exist: wait, take misoprostol, or have a short surgical procedure (ERPC). None is medically superior for an uncomplicated loss. Grief does not scale with gestational age and does not run on a timeline.
