Missed (silent or delayed)
The pregnancy has stopped developing but remains in the womb, usually without bleeding.
Understanding a Missed Miscarriage: Why It Happens and What Comes Next
A missed miscarriage means a pregnancy has stopped developing but has not yet come away. There is often no bleeding or pain, so the news usually arrives at a scan. This page covers how the diagnosis is checked, the usual reason it happens and the choices still open to you, including genetic testing.
Unless you are bleeding heavily, in severe pain, have a fever or feel unwell, there is usually time to take in the news, ask questions and decide what feels right. At London Miscarriage Clinic we can help you check the diagnosis and think through testing.
The basics
What 'missed' means
A missed miscarriage is a pregnancy that has stopped developing inside the womb but has not yet come away. It is also called a silent or delayed miscarriage. 'Missed' is not a judgement on you or on anyone caring for you. It simply means the physical miscarriage has not started.
Because pregnancy hormones may remain raised for some time, you can go on feeling pregnant, and a home test can still read positive. With no pain or bleeding, the news usually comes at a routine or early scan, often as a complete shock. You are far from alone: about 15 in every 100 known pregnancies end in miscarriage.
A pregnancy sac with no embryo inside, sometimes called an anembryonic pregnancy or 'blighted ovum', is a form of missed miscarriage, so most of what follows applies to it too.
Words you may hear
Missed, incomplete or complete?
Scan reports use several labels. They describe what is still in the womb, not how significant your loss is.
Anembryonic pregnancy
A sac formed but no embryo is seen inside it. It is a type of missed miscarriage.
Incomplete
Bleeding has started and some tissue has passed, but some remains in the womb.
Complete
All the tissue has passed and bleeding has settled. If no earlier scan showed the pregnancy in the womb, you may be asked back for blood tests or scans to make sure it was not growing elsewhere.
Diagnosis
How the diagnosis is made
Diagnosis rests on an ultrasound scan, usually an internal (transvaginal) one because it gives the clearest early view. The person scanning looks for a heartbeat, then measures how long the embryo is (its crown–rump length, or CRL) or, if no embryo is visible, the average width of the sac (the mean sac diameter).
NICE accepts that one scan cannot be completely accurate. Below certain sizes it always asks for a repeat scan, and even above them it advises a second opinion, a repeat scan or both before miscarriage is confirmed. It also advises against relying on the date of your last period alone, and says waiting for a repeat scan does not harm a pregnancy that is still developing.
When one scan is not enough
NICE's rules for internal scans, in summary. After an abdominal scan alone, NICE advises a repeat scan at least 14 days later before a diagnosis is made.
| Scan finding | What should happen before miscarriage is confirmed |
|---|---|
| Heartbeat not seen, embryo measuring less than 7 mm | Repeat scan after at least 7 days; more than one may be needed |
| Heartbeat not seen, embryo measuring 7 mm or larger | Second opinion and/or a repeat scan after at least 7 days |
| No embryo visible, sac measuring less than 25 mm | Repeat scan after at least 7 days; more than one may be needed |
| No embryo visible, sac measuring 25 mm or larger | Second opinion and/or a repeat scan after at least 7 days |
Not sure which applied to you? Ask your early pregnancy unit. A repeat scan or second opinion is part of careful diagnosis, and asking for one is reasonable. If you would prefer to have it privately, our repeat early scan and second-opinion scan are described under how we can help.
Causes
Why a pregnancy stops developing
The most common recognised reason is a chromosome change in the pregnancy. Chromosomes carry the genetic instructions in every cell, and an embryo needs the right number, arranged the right way. With an extra one, a missing one or a whole extra set, development often cannot continue. About half of early miscarriages happen this way.
Most of these changes arise by chance, as the egg or sperm forms or in the first cell divisions, and are not inherited. Eggs are more likely to carry the wrong number of chromosomes as they age, a major reason miscarriage becomes more common from the late thirties (our page on miscarriage statistics has the age figures).
Other causes, such as a difference in the shape of the womb or the clotting condition antiphospholipid syndrome, are found less often and are mainly looked for after repeated losses. If a single miscarriage is not tested, its cause usually stays unknown.
When a sample is tested
The chromosome changes found most often
Of miscarriages that show a chromosome change, the RCOG guideline (2023) reports roughly this mix. Figures vary between laboratories and methods. Our page on chromosomal causes covers each in depth.
About 52 in 100
Trisomy: one extra chromosome
Three copies of one chromosome instead of two. It becomes more common as the egg gets older.
About 19 in 100
Polyploidy: a whole extra set
Usually triploidy, with 69 chromosomes instead of the usual 46.
About 15 in 100
Monosomy: one chromosome missing
Usually monosomy X, where only one sex chromosome, an X, is present.
About 6 to 7 in 100
Structural changes
A piece of a chromosome is missing, extra or rearranged. Sometimes a parent carries a balanced form of the change, which is when testing parents may help.
Common worries
Everyday things that are not thought to cause it
Many people replay the days before the scan. The charity Miscarriage UK lists these among the things that do not appear to raise the risk, even though people often worry about them.
- Exercise: including workouts before you knew you were pregnant.
- Sex: it has not been shown to cause miscarriage.
- Work: full-time jobs and long periods of sitting or standing.
- Everyday lifting: carrying children, shopping and other ordinary loads.
- Flying: air travel does not appear to raise the risk.
- Stress and worry: there is no clear evidence that stress causes miscarriage, although loss itself is stressful.
Genetic testing
Why testing may still be possible while the pregnancy is in the womb
A missed miscarriage leaves something other miscarriages often do not: time. While the pregnancy tissue is still in place, there are two possible routes to finding out whether a chromosome change was involved.
A blood sample, before the pregnancy passes
While the pregnancy remains in the womb, its placental tissue keeps releasing tiny fragments of DNA into your blood. A blood test can count them to look for extra or missing chromosomes, as NIPT screening does. This cell-free DNA (cfDNA) testing is not standard NHS care. UK research, including studies funded by Tommy's, is still evaluating it, and some private services offer it.
Timing matters. In a large Danish study, placental DNA fell once the tissue had passed, dropping noticeably after 12 hours. About 1 in 11 samples gave no result while tissue was in place, against more than 1 in 4 taken 12 to 24 hours after it passed. A scan shortly before the sample makes sense: it confirms tissue is still there and can reveal a twin that stopped developing earlier, which can confuse the result.
If you are wondering whether a blood-based test could work for you, our genetic counsellors can go through your timing and plans for treatment with you before anything is decided.
A tissue sample, after it passes or is removed
The established route is to test the tissue itself in a genetics laboratory. In the UK, the RCOG guideline recommends offering it from the third miscarriage or after any second-trimester loss; doctors may investigate after two losses if they suspect an underlying cause. Tommy's notes it is often limited in practice to tissue removed during surgery, with results taking weeks or months.
Tissue must reach the laboratory fresh. Tissue placed in formalin, the preservative used for routine microscope examination, usually cannot be used for these tests. In one large study, about 1 in 3 women could not collect testable tissue, or collected a sample likely to be their own tissue rather than the pregnancy's.
Privately, we arrange pregnancy tissue testing after a genetic counselling appointment, so that how the sample will be collected and sent can be planned in advance.
What neither route can promise
Across 8 studies covering 552 miscarriages, blood testing picked up roughly 78 in 100 chromosome changes that tissue testing had shown (triploidy was left out of that count), and wrongly flagged about 9 in 100 pregnancies whose tissue was normal. In the largest single study, of 1,000 women, about 1 in 9 blood results were inconclusive. Counting-based blood tests miss triploidy. Blood tests also cannot detect balanced rearrangements or very small changes, and may miss mosaic results.
Because the DNA comes from the placenta, a blood result can occasionally differ from the pregnancy, so it is best treated as a screening-type finding. Tissue testing has limits too: older culture-based methods fail in about 1 in 5 samples, and the mother's own cells can be tested by mistake. Blood test or tissue test? compares the two in detail.
Before anything is done
Things to consider before medical or surgical management
Make sure the diagnosis is certain
Below NICE's size limits, a repeat scan at least 7 days later is needed before a diagnosis. Above them, NICE advises a second opinion, a repeat scan or both. If you have any doubt, ask.
Ask how much time you have
NICE recommends waiting 7 to 14 days as the usual first option, unless you have a higher risk of heavy bleeding, an infection or a previous traumatic pregnancy experience.
Decide about genetic testing
A blood-based test needs the tissue still in the womb, ideally before tablets or surgery. Tissue testing needs a fresh sample, not one placed in formalin.
Choose what suits you
Waiting, tablets and surgery each have trade-offs. If waiting is not acceptable to you, NICE says you should be offered tablets, and surgery may also be an option.
How long it can take, and what each option involves
Based on NICE guidance and UK research. Timings vary widely from person to person.
| Option | What happens | Timing |
|---|---|---|
| Waiting (expectant management) | The miscarriage happens naturally, with advice on pain relief and where to get urgent help. Home pregnancy test 3 weeks later. | Days to weeks. In one UK study of women who chose to wait with a missed miscarriage, about 3 in 10 had passed within a week, 6 in 10 within 2 weeks and 3 in 4 by 46 days. |
| Tablets (medical management) | Mifepristone 200 mg by mouth, then misoprostol 800 micrograms 48 hours later. Home pregnancy test 3 weeks later. | Contact your unit if bleeding has not started within 48 hours of the misoprostol. |
| Surgery (surgical management) | Manual vacuum aspiration under local anaesthetic in a clinic, or a procedure in theatre under general anaesthetic. | On a planned date. Ask beforehand if you would like the tissue sent for genetic testing. |
Questions to take to your early pregnancy unit
Worth writing down before your next appointment. If you have only just been told, our page for the first few days after a diagnosis may help too.
What did my scan measure, and has the diagnosis been checked with a repeat scan or second opinion, as NICE advises?
How long can I safely wait before deciding how to manage this?
Can tissue be sent fresh for genetic testing, and when would a blood sample need to be taken?
Who do I call out of hours if bleeding becomes heavy, or I get a fever or severe pain?
Help and support
Your NHS care and where to find support
Your NHS early pregnancy unit is the first place to go for diagnosis, management and questions about tissue testing. Your GP or the unit can explain what is available locally if you have had more than one loss.
For emotional support, Miscarriage UK runs a support line on 0303 003 6464, and Tommy's has information and support from midwives.
If you are thinking about private testing, wherever you go, including to us, it is worth asking which method the laboratory uses and what happens if there is no result.
How we can help
How London Miscarriage Clinic can help with a missed miscarriage
We can support you at each stage: checking the diagnosis, planning genetic testing while there is still time, and making sure you have recovered afterwards. These appointments sit alongside your NHS care, and you can book them without a referral or call us to talk through which one fits. London Miscarriage Clinic is part of London Pregnancy Clinic, so booking opens on the London Pregnancy Clinic website.
Online, 30 minutes
Genetic counselling
With a missed miscarriage there may still be time to test. In a video appointment, one of our registered genetic counsellors helps you work out whether a blood or tissue sample is realistic before tablets, surgery or natural passing, and what either result could tell you. If tissue testing suits you, we can arrange it.
6–9 weeks
Repeat early scan
NICE advises a repeat scan at least 7 days after the first when the pregnancy is below its size limits, and a repeat scan or second opinion above them. Booked as our viability scan, it measures the pregnancy again and looks for a heartbeat. Your early pregnancy unit can also repeat the scan on the NHS.
From around 10 weeks
Second-opinion scan
If the missed miscarriage was found at around 10 weeks or later and you would like it checked independently, Dr Fred Ushakov can scan you and explain what he sees. He gives a diagnostic opinion only: planning how the miscarriage is managed stays with you and your early pregnancy unit.
After your first period
Post-miscarriage scan
Once the miscarriage has passed or been treated and your first period has come, this ultrasound and review checks that your womb has recovered and no tissue has been left behind. You can also ask our gynaecology and midwifery team about trying again. It does not diagnose a miscarriage.
Questions people ask about missed miscarriage
Why didn't my body recognise that the pregnancy had stopped?
No one fully knows why some miscarriages begin within days and others take much longer. Miscarriage UK notes the delay can be a matter of days or several weeks. With no pain or bleeding, there is often no way anyone could have known without a scan, so please do not blame yourself for not noticing.
Is a missed miscarriage a sign that my partner or I have a genetic problem?
Usually not. Most chromosome changes behind a miscarriage happen by chance and are not inherited. Testing parents' chromosomes is suggested only in particular situations, such as when tissue shows an unbalanced rearrangement. Our page on parental karyotype testing explains when. As Miscarriage UK points out, most people who miscarry, even more than once, go on to have a healthy pregnancy.
I smoked or drank alcohol before I knew I was pregnant. Did that cause it?
Across large groups of people, smoking and drinking alcohol in early pregnancy, especially more heavily, go along with a raised chance of miscarriage. But a link in a population does not tell you what happened in your pregnancy.
As Miscarriage UK points out, even when a risk factor applies to you, something else entirely may have caused your loss, and when miscarriages are tested, a chance chromosome change is the most common finding. Please try not to carry this as blame. Was it something I did? looks at this in more depth.
Is genetic testing worth it after a first miscarriage?
UK guidance recommends it from the third miscarriage, so after a single miscarriage it is not usually offered on the NHS. Some people choose private testing because an explanation helps them. On average, finding a chromosome cause also points to a better outlook next time than a loss in which the chromosomes were normal. No test can promise to find a cause.
Does a missed miscarriage take longer to pass than other types?
Often, yes. In one UK study of women who chose to wait, about half of incomplete miscarriages (where bleeding had already started) had completed within a week, compared with about 3 in 10 missed miscarriages. That is one reason some people choose tablets or surgery instead.
Can I have a private scan to check the diagnosis before I decide on treatment?
Yes. You can book a repeat early scan, or from around 10 weeks a second-opinion scan, with us directly and without a referral. If the scan is a repeat, NICE advises leaving at least 7 days after the first. You will have a report to share with your early pregnancy unit, which can then plan the next steps with you.
About this information
The information here is for general education. It cannot replace advice from the professionals looking after you, who know your history and your scan findings. If you have heavy bleeding, severe pain, a fever or feel faint, contact your early pregnancy unit or call NHS 111 straight away, or call 999 in an emergency.
Contact
Talk to us about your missed miscarriage
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.
- NICEEctopic pregnancy and miscarriage (NG126): diagnosis of viable intrauterine pregnancy and of tubal ectopic pregnancy2026
- NICEEctopic pregnancy and miscarriage (NG126): management of miscarriage2026
- The Lancet (Quenby et al.), accepted manuscript via University of WarwickMiscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss2021
- Royal College of Obstetricians and GynaecologistsRecurrent Miscarriage (Green-top Guideline No. 17)2023
- BMJ (Luise et al.)Outcome of expectant management of spontaneous first trimester miscarriage: observational study2002
- Prenatal Diagnosis (Pauta et al.)Genome-wide cell-free DNA analysis for aneuploidy detection in miscarriages: test performance meta-analysis2025
- The Lancet (Schlaikjaer Hartwig et al.)Cell-free fetal DNA for genetic evaluation in Copenhagen Pregnancy Loss Study (COPL): a prospective cohort study2023
- Human Reproduction (El Sammaa-Aru et al.)How big is the time window for cell-free fetal DNA testing after pregnancy loss and which factors are associated with a successful result?2026
- Tommy'sUsing fetal DNA to detect chromosomal abnormalities following miscarriageAccessed October 2026
- Miscarriage UKMissed miscarriageAccessed October 2026
- Miscarriage UKCauses and risk factors of miscarriageAccessed October 2026
- North West Genomic Laboratory Hub (Manchester University NHS Foundation Trust)Acceptance criteria and requirements for solid tissue samples following loss of pregnancy2025