An initial scan
Confirms the pregnancy is in the womb, checks for a heartbeat, dates the pregnancy and describes the haematoma's size and position relative to the sac.
Subchorionic Haematoma in Early Pregnancy
A subchorionic haematoma — also called a subchorionic haemorrhage, and spelt 'hematoma' in American sources — is a collection of blood between the pregnancy sac and the wall of the womb. It is a common finding on early pregnancy scans: sometimes it explains bleeding, sometimes it is found by chance. Research links it with a higher chance of miscarriage, but most pregnancies with a haematoma continue, and a follow-up scan shows how it is changing.
If you are bleeding heavily (soaking a pad soon after putting it on), have severe tummy pain or pain in your shoulder, or feel faint or dizzy, call 999 or go to A&E. Do not wait for a scan appointment.
Available atLPC City (E1)LPC West (SW10)
When to get help straight away
The NHS advises calling 999 if you are pregnant and bleeding and the bleeding is heavy (soaking a period pad soon after putting it on), you have severe tummy pain or pain in your shoulder, or you feel sick, faint or dizzy. These can be signs of a miscarriage, an ectopic pregnancy or another problem that needs urgent treatment. For light bleeding or spotting with no pain or only mild pain, contact your maternity unit or early pregnancy unit, or call NHS 111. Early pregnancy units are free on the NHS, and a private scan appointment is never a substitute for emergency care.
The basics
What is a subchorionic haematoma?
The chorion is the outer membrane of the pregnancy sac; part of it goes on to form the placenta. A subchorionic haematoma forms when an edge of the chorion separates slightly from the lining of the womb and blood collects in the gap. 'Haematoma' means a collection of blood, and 'subchorionic' means beneath the chorion.
On an ultrasound scan it usually appears as a dark crescent, triangle or irregular area at the edge of the sac. The sonographer notes where it sits and how large it looks compared with the pregnancy sac, which a 2018 study found to be the most useful guide to outcome.
In most cases no single cause is found. Researchers have looked at possible links with IVF and other assisted conception, clotting and autoimmune conditions, and infection, but the exact cause remains unclear. How often it is seen varies hugely between studies — reported figures range from 0.48 per cent to 39.5 per cent (Xu et al., 2024 review) — depending on who is scanned, when, and how small a collection is counted.
Symptoms
Symptoms: often painless bleeding — or none at all
The most common symptom is vaginal bleeding in the first half of pregnancy. It ranges from light spotting to heavier bleeding with clots. It is usually painless; cramping alongside it is less common.
Some women have no symptoms at all, and the haematoma is noticed incidentally on a routine early scan. Finding one this way can be unsettling, but it does not by itself mean something is wrong with the pregnancy.
Bleeding in early pregnancy has many possible causes: implantation, changes to the blood vessels of the cervix, infection, a subchorionic haematoma, miscarriage and ectopic pregnancy among them. Bleeding alone cannot tell you which it is — an ultrasound scan, sometimes with blood tests, is needed to find out. Our guide on bleeding in early pregnancy: when to worry and when to get a scan explains the differences.
Subchorionic haematoma in numbers
Figures from published studies describe groups of women, not any one pregnancy — see the sources at the foot of this page.
9 in 10 Pregnancies that did not miscarry among 516 women with first-trimester bleeding, a heartbeat on scan and a haematoma (9.3% miscarried; Bennett et al., Radiology 1996)
17.6% vs 8.9% Miscarriage rate with and without a haematoma, pooled from 7 studies of 72,438 women (Tuuli et al., Obstet Gynecol 2011)
19.6% vs 3.6% First-trimester pregnancy loss when the haematoma was found at or before 7 weeks, compared with after 8 weeks (Heller et al., J Ultrasound Med 2018)
The evidence
What the evidence says about outcomes
The research is mixed. Some studies link a subchorionic haematoma with problems later in pregnancy; others find no increase in risk. The most widely cited analysis, a 2011 systematic review and meta-analysis by Tuuli and colleagues, pooled seven studies comparing 1,735 women who had a haematoma with 70,703 who did not.
It found a higher rate of miscarriage (17.6 per cent compared with 8.9 per cent) and of stillbirth (1.9 per cent compared with 0.9 per cent). Put the other way round, more than eight in ten women with a haematoma in these studies did not miscarry, and around 98 in 100 did not have a stillbirth.
The same review found a higher rate of placental abruption, when the placenta separates early (3.6 per cent compared with 0.7 per cent), and smaller increases in preterm birth and waters breaking early before 37 weeks, but no clear link with a baby being small or with pre-eclampsia. A later meta-analysis of 16 studies (Yan et al., 2023) confirmed the link with miscarriage but found no significant link between a first-trimester haematoma and preterm birth — so the picture for later pregnancy is less certain.
Outcomes with and without a haematoma
Pooled rates from the Tuuli et al. 2011 meta-analysis (7 studies). These are averages from mostly older observational studies and cannot predict what will happen in an individual pregnancy.
| Outcome | Without a haematoma | With a haematoma |
|---|---|---|
| Miscarriage | 8.9% | 17.6% |
| Stillbirth | 0.9% | 1.9% |
| Placental abruption | 0.7% | 3.6% |
| Preterm birth | 10.1% | 13.6% |
| Waters breaking early (preterm) | 2.3% | 3.8% |
| Small baby or pre-eclampsia | No significant difference | No significant difference |
What seems to affect the outlook
Size and timing both appear to matter. In a study of 516 women with first-trimester bleeding, a live baby and a haematoma, the miscarriage rate was 18.8 per cent when the separation was large, compared with 7.7 per cent for small and 9.2 per cent for moderate haematomas. Miscarriage was also more common when bleeding happened at 8 weeks or earlier (13.7 per cent) than after 8 weeks (5.9 per cent), and in women aged 35 or over (Bennett et al., 1996).
A 2018 study of 434 scans between 6 and 11 weeks found that the size of the haematoma compared with the pregnancy sac was the measurement most closely linked to outcome, and that haematomas found at or before 7 weeks carried a higher rate of loss than those found after 8 weeks (Heller et al., 2018).
Keep in mind that these figures come from pregnancies in which a live baby had already been seen on scan. The clinician who scans you can explain what your own images show and what that means for you.
Monitoring
How a subchorionic haematoma is monitored
Watching the bleeding
NICE advises that, with a pregnancy confirmed in the womb and a heartbeat seen, you should return for assessment if bleeding gets worse or carries on beyond 14 days. If you have had a miscarriage before, NICE recommends a different approach (see the treatment question below).
A follow-up scan
Your clinician may suggest a repeat scan to check the pregnancy is growing and the haematoma is getting smaller. Many resolve on their own.
Routine antenatal care
If the bleeding stops, NICE advises starting or continuing routine antenatal care. Tell your midwife about the haematoma at booking.
Day to day
Practical advice
There is no agreed, evidence-based treatment for a subchorionic haematoma, so day-to-day advice varies between clinicians. These general points may help while you wait for a follow-up scan.
Follow the advice you were given
Some clinicians suggest avoiding strenuous exercise, heavy lifting or sex while bleeding continues. Evidence either way is limited, so ask the clinician who scanned you what they recommend for your situation.
Keep a simple bleeding diary
Note when bleeding starts and stops, how heavy it is, its colour and any pain. It gives your midwife, GP or early pregnancy unit a clearer picture.
Know your local early pregnancy unit
NICE expects early pregnancy assessment services to be available 7 days a week in every region. Save the number, and check how your local unit accepts referrals.
Look after yourself
Bleeding in pregnancy is frightening, even when the scan is reassuring. Our miscarriage support page lists charities offering support whatever the outcome.
Scans
Scans for bleeding and follow-up
If you are bleeding, your NHS early pregnancy unit can assess and scan you free of charge. A private scan is an option if you would like to be seen at a time that suits you, or would like a follow-up scan to see how a haematoma is changing. Every scan is performed by a fetal medicine specialist; see bleeding in early pregnancy for how we can help.
6–9 weeks
Viability scan
Heartbeat, location of the pregnancy, dating — and a look at any haematoma.
10–11 weeks
10-week scan
Growth and heartbeat, with the earliest structural check of your baby.
12–16 weeks
Early fetal scan
A detailed early anatomy examination of your baby.
Subchorionic haematoma — your questions
Is a subchorionic haematoma the same as a subchorionic haemorrhage?
Yes. The two terms are used interchangeably for the same finding. You may also see 'subchorionic hematoma' (the American spelling), 'SCH' or 'subchorionic bleed' in scan reports and online.
Does a subchorionic haematoma mean I will miscarry?
No. Studies find a higher chance of miscarriage than in pregnancies without a haematoma, but most pregnancies continue. In one study of women with bleeding, a heartbeat on scan and a haematoma, about nine in ten did not miscarry. Size, how early it is found and your age all seem to affect the picture — your clinician can explain what your scan shows.
Will it go away on its own?
Many subchorionic haematomas resolve on their own as the pregnancy grows. A follow-up scan is the way to see whether it is getting smaller. NICE advises going back for further assessment if bleeding becomes heavier or lasts more than 14 days.
Is there any treatment?
There is no treatment that removes a haematoma, and no agreed treatment guideline. Separately, NICE recommends vaginal progesterone for a specific group — women with bleeding, a pregnancy confirmed in the womb by scan and a previous miscarriage. That recommendation is about bleeding in early pregnancy generally, not haematomas specifically. Whether that applies to you is a decision for your doctor or early pregnancy unit.
My blood group is rhesus negative. Do I need anti-D?
Under current NICE guidance, anti-D is not offered for a threatened miscarriage (bleeding with an ongoing pregnancy) up to 11 weeks and 6 days. It may be considered between 12+0 and 12+6 weeks if bleeding is heavy or repeated. This guidance covers early pregnancy only; if you bleed later in pregnancy, anti-D is assessed differently. Ask your maternity team, who will advise based on your gestation and symptoms.
Can a subchorionic haematoma affect the rest of my pregnancy?
Some studies link a haematoma with a higher rate of placental abruption and, to a lesser degree, preterm birth and waters breaking early; a more recent analysis found no significant link with preterm birth. Let your midwife know about it so it is in your notes, and seek advice promptly if you have bleeding, pain or fluid loss later in pregnancy.
Should I have a private scan if I am bleeding?
If you are bleeding heavily, in severe pain or feel faint, go to A&E or call 999. For lighter bleeding, your NHS early pregnancy unit or maternity unit can assess you free of charge. A private viability scan is an option if you would like to be seen sooner or want a follow-up scan — call 020 3687 2939 and we will advise.
About this information
This information is intended for general educational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional for guidance specific to your individual circumstances. If you have concerns about your pregnancy or baby's wellbeing, contact your midwife, GP or maternity unit promptly.
Contact
Questions about a scan finding?
Sources & clinical references
The figures and clinical statements on this page are drawn from the sources below. Guidance evolves — always discuss your individual circumstances with a clinician.
- Obstetrics & Gynecology (Tuuli et al.)Perinatal outcomes in women with subchorionic hematoma: a systematic review and meta-analysis2011
- Radiology (Bennett et al.)Subchorionic hemorrhage in first-trimester pregnancies: prediction of pregnancy outcome with sonography1996
- Journal of Ultrasound in Medicine (Heller et al.)Subchorionic hematoma: correlation of grading techniques with first-trimester pregnancy outcome2018
- American Journal of Obstetrics & Gynecology MFM (Yan et al.)Subchorionic hematoma and risk of preterm delivery: a systematic review and meta-analysis2023
- Medicine International (Xu et al.)Subchorionic hematoma: research status and pathogenesis (review)2024
- NHSVaginal bleeding in pregnancy2026
- NICEEctopic pregnancy and miscarriage (NG126): management of miscarriage — threatened miscarriage2026
- NICEEctopic pregnancy and miscarriage (NG126): early pregnancy assessment services2026
- NICEEctopic pregnancy and miscarriage (NG126): anti-D immunoglobulin prophylaxis2026
- Cleveland ClinicSubchorionic hematoma2026