Genetics advice, early scans and NIPT
What the NHS offers at each stage
When tests have shown that a miscarriage was caused by a chromosome change, planning the next pregnancy usually comes down to three questions: what the result means for the future, how early the baby can be checked on a scan, and which screening or diagnostic tests suit you.
Most chromosome changes in a miscarriage happen by chance and are unlikely to happen again. This page explains the NHS pathway step by step, and how our genetic counsellors and fetal medicine specialists can support it.
Where you are starting from
Chromosome changes are the commonest cause of early miscarriage. Around half of early losses happen because the pregnancy developed with the wrong number or arrangement of chromosomes, and in most cases this happens by chance while both parents' own chromosomes are normal. That does not make the loss any easier, but it is useful information when you plan what comes next.
On balance, it is also encouraging. UK guidance on repeated miscarriage from the Royal College of Obstetricians and Gynaecologists (RCOG) notes that a chromosome change found in a miscarriage is linked to a better outlook in the following pregnancy than a miscarriage in which the chromosomes were normal. Age still counts, and this may not apply where a parent carries a chromosome rearrangement, so the exact finding matters.
According to the NHS, you can try again once your miscarriage symptoms have gone and you feel ready, and most women who have miscarried later have a successful pregnancy. The rest of this page works through three questions that can help you plan.
Question 1
A genetic counsellor or clinical geneticist can turn a laboratory report into a plan. Ideally this happens before you try again, but it is still worthwhile early in a new pregnancy. Bring the written report from the previous test, because the exact wording matters.
'Chromosomal' covers several different findings: an extra chromosome (a trisomy), a missing one (a monosomy, such as monosomy X), a whole extra set (triploidy), or a piece of chromosome that is missing, extra or rearranged. Each has a different meaning for the future. Our guide to understanding your result explains the terms.
Trisomies, monosomies and triploidy usually arise by chance and are not passed down. Trisomies become more common as the egg-provider gets older, but they do not usually mean that either partner has a chromosome problem. An unbalanced rearrangement is different, because it sometimes comes from a parent who carries a balanced version without knowing it.
Often not. UK guidance (RCOG, 2023) recommends offering a karyotype, a blood test of both partners' chromosomes, when the pregnancy tissue showed an unbalanced structural rearrangement. After a chance trisomy it is not routinely needed, though European guidance (ESHRE) suggests deciding case by case, for instance where there is a family history of chromosome conditions. See parental karyotyping.
Most chance chromosome changes are unlikely to happen again. After a miscarriage with a trisomy, one North American laboratory study of later prenatal tests found a trisomy that can continue in pregnancy, such as Down's syndrome, about 1.8 times as often as expected for the mother's age.
The starting chance is low for most people (for Down's syndrome, about 1 in 900 at age 30, at 16 weeks of pregnancy, according to the NHS screening programme), so the overall chance usually stays low, and screening is available.
If one of you carries a balanced rearrangement, further miscarriage is more likely, but most couples still have a healthy baby. In a large Dutch study quoted by the RCOG, 83 in 100 carrier couples had a healthy child, much the same as couples with repeated miscarriages who were not carriers (84 in 100), although carriers more often had another miscarriage (49 in 100, against 30 in 100). A pregnancy with the unbalanced form continuing into the second trimester was uncommon, at under 1 in 100.
By type of finding
A general guide only. Your own report, age and history may change what applies, which is why a genetics review is worthwhile.
| Previous finding | Usually inherited? | Parents tested? | Points for the next pregnancy |
|---|---|---|---|
| Trisomy (an extra chromosome) | No. Usually chance, and more common as the egg-provider gets older | Not usually | NHS screening, with genome-wide NIPT as an option; diagnostic testing if a result is higher chance |
| Monosomy X (one X chromosome instead of two) | No. Usually chance | Not usually | Routine NHS screening and scans; discuss anything else on the report with a genetic counsellor |
| Triploidy (a whole extra set of chromosomes) | No. Usually chance | Not usually | If it was a partial molar pregnancy, follow the specialist centre's hCG follow-up and its advice on timing; see molar pregnancy |
| Unbalanced rearrangement (a piece missing or extra) | Sometimes. A parent may carry a balanced version | Yes, usually offered to both | Genetics referral; if a parent is a carrier, options include CVS or amniocentesis, or IVF with embryo testing (PGT-SR) |
| Small deletion or duplication, or an uncertain finding | Depends on the finding | Only if a genetics team advises it | Ask whether it is relevant at all before planning extra tests |
Question 2
After a loss, many parents want early reassurance that a new pregnancy is developing. A specialist scan at around 10 weeks can examine some major structures that can already be seen by this point. It also confirms the heartbeat, measures the baby to check the dates and shows how many babies there are. It does not replace the 11–14-week and 20-week scans.
There are real limits this early. The skull bones do not usually show clearly until about 11 weeks, and part of the bowel normally sits outside the tummy until around then, so a full check of anatomy is not yet possible. International guidance from ISUOG places the main early anatomy check at 11 to 14 weeks, with many details best seen at around 13 weeks, and some conditions only become visible later in pregnancy.
A scan and a chromosome test answer different questions. Ultrasound shows how the baby is forming but cannot read chromosomes; NIPT screens DNA from the placenta for chromosome changes but cannot show the baby's structure. Scanning before NIPT also confirms a single ongoing pregnancy, which matters because a twin that stopped developing early can affect NIPT results. For these reasons we always perform NIPT together with a scan.
Typical timings. If you have pain or bleeding in early pregnancy, your NHS early pregnancy unit can assess you free of charge; later in pregnancy, contact your maternity unit.
| When | Scan | What it can show | NHS or private |
|---|---|---|---|
| 6–9 weeks | Early viability scan | That the pregnancy is in the womb, the heartbeat and the dates | NHS if you have pain or bleeding, and sometimes for reassurance after recurrent miscarriage; otherwise private |
| Around 10 weeks | Specialist 10-week scan | Heartbeat, growth, number of babies and some major structures already visible | Private |
| 11–14 weeks | Dating scan, with the neck measurement if you choose combined screening | Dates, and the nuchal translucency used in the combined test | NHS, offered to everyone |
| 12–16 weeks | Early fetal scan | A more detailed early anatomy check, at the stage when many structures are best seen | Private |
| Around 20 weeks | Mid-pregnancy anomaly scan | A detailed anatomy check, including structures that develop later | NHS, offered to everyone |
Question 3
Every pregnant woman in England is offered screening for Down's, Edwards' and Patau's syndromes (trisomies 21, 18 and 13). A private genome-wide NIPT looks more widely. Both are screening tests: they estimate a chance rather than give a diagnosis.
A blood test between 10 and 14 weeks and a scan measuring the fluid at the back of the baby's neck between 11 and 14 weeks, combined with your age. A result of 1 in 150 or higher counts as higher chance.
Offered as a next step after a higher-chance screening result, alongside the choice of a diagnostic test or no further tests. It looks only for trisomies 21, 18 and 13, not other chromosome conditions.
A blood test that also looks at the other chromosomes and, in some tests, for missing or extra pieces of chromosome. See NIPTIFY and our other NIPT options.
It can be. Many of the chromosome changes found in miscarriages are something other than an extra chromosome 21, 18 or 13, the only three conditions that NHS screening looks for. A genome-wide test also checks the remaining chromosomes, and some parents find that reassuring after a loss caused by a rarer trisomy.
It also has important limits. When genome-wide NIPT flags a rarer trisomy, the change is often confined to the placenta rather than the baby: in a national Dutch study, only about 6 in 100 such results were confirmed in the baby. Any higher-chance result needs a diagnostic test before decisions are made, and the wait can be stressful. NIPT cannot detect balanced rearrangements, and triploidy can be missed.
Whether it suits you depends on what was found before and how you would use the answer. After a chance trisomy, it may add reassurance alongside NHS screening. If a parent carries a rearrangement, a diagnostic test is often the clearer route; for example, NHS NIPT is not offered to a mother who carries a balanced translocation involving chromosome 21, 18 or 13. Talking it through with a genetic counsellor before booking can make the choice clearer.
We offer NIPTIFY, one of the most comprehensive genome-wide NIPT options currently available privately in the UK, from 10 weeks. The scan is always included, because we do not offer NIPT on its own, and the package costs £690. Alongside whole-chromosome changes, it screens for missing or extra pieces of chromosome larger than about 1 Mb (roughly a million DNA letters).
These figures describe groups of people, not any one pregnancy. The sources are listed at the foot of this page.
Diagnosis rather than screening
Screening estimates a chance, whereas a diagnostic test examines the baby's chromosomes directly. Chorionic villus sampling (CVS) takes a tiny sample of the developing placenta, usually between 11 and 14 weeks and not before 10 weeks. Amniocentesis takes a small amount of the fluid around the baby, from 15 weeks.
Either test may be worth discussing if a screening result is higher chance, if a parent carries a balanced rearrangement, or if a scan raises a concern. The laboratory can be told about the previous result so that the analysis is planned around it, for example checking specifically for the unbalanced form of a parent's known rearrangement alongside a wider chromosome analysis; your genetics team will advise on what applies to you.
Where a change seen on NIPT or CVS might lie in the placenta rather than the baby, amniocentesis generally reflects the baby's own chromosomes more closely.
When an experienced specialist performs either procedure, the added chance of miscarriage is probably less than 1 in 200 (RCOG); the NHS screening leaflet gives about 1 in 200. After a loss, that can be a heavy number to weigh, and there is no single right answer.
We do not carry out CVS or amniocentesis at London Pregnancy Clinic. If a diagnostic test is being considered, we explain the options and can help you arrange a referral to your NHS fetal medicine unit, where these tests are free when recommended, or to a private fetal medicine consultant. Our amniocentesis guide compares the two procedures.
Whether you see an NHS midwife, a genetic counsellor or our team, these details help the people advising you.
The full laboratory report from the previous test, not only a summary of the result
The dates of any previous losses and how many weeks pregnant you were each time
Any chromosome (karyotype) results for either partner
Letters about hormone (hCG) follow-up, if a molar pregnancy was involved
Results of any recurrent miscarriage tests, such as antiphospholipid or thyroid blood tests
Our services
These options sit alongside your NHS maternity care. Scans take place at our clinics in the City of London and West London, and genetic counselling is by video.
Before or early in pregnancy
A registered genetic counsellor, through Jeen Health, reviews your previous report and what it means for next time. A 60-minute appointment (£140) suits a more complex history.
Complex findings
A doctor-led appointment with Dr Harry Leitch, Consultant in Clinical Genetics, suited to rearrangements, uncertain findings or a relevant family history. Enquire to book.
If advised
If a genetics review recommends it, one or both partners can have their chromosomes checked through Jeen Health: £290 for one person, £550 for a couple.
6–9 weeks
An early check by a fetal medicine specialist that the new pregnancy is in the womb, with a heartbeat.
10–11 weeks
Heartbeat, growth and a first look at some major structures that can be seen this early. An addition to your 11–14-week and 20-week scans, not a replacement.
From 10 weeks
Genome-wide NIPT, always performed with a scan. It is a screening test, so a higher-chance result needs a diagnostic test to confirm it.
Not usually in itself. The NHS advises trying again when you feel ready and your miscarriage symptoms have gone, and our guide to preparing for your next pregnancy covers timing. Two situations are worth settling first. After a partial molar pregnancy, follow the hCG monitoring and timing advice from the specialist centre. And if a genetics review or parental karyotype has been recommended, having the results before you conceive keeps more options open.
No. ISUOG advises that NIPT should not be used on its own without the scan at 11 to 14 weeks, because a blood test cannot show how the baby is forming. A 10-week scan is an earlier, extra look rather than a substitute. Keep your NHS dating scan and your 20-week anomaly scan, and tell your midwife about any private results.
It is a fair question, and the answer is personal. The NHS screening programme puts the chance of Down's syndrome at around 1 in 100 at age 40, and it may be slightly higher after a trisomic miscarriage. Some people choose screening first and keep diagnostic testing for a higher-chance result; others want a definite answer from the start and accept the small procedure risk. A genetic counsellor can set out the numbers for your age and history before you decide.
European guidance (ESHRE) describes three main routes: trying again naturally, with the offer of CVS or amniocentesis; IVF with testing of embryos for the rearrangement (PGT-SR); or using donor eggs or sperm. PGT-SR may reduce further miscarriages, but it has not been shown to raise the overall chance of a baby or to shorten the time to pregnancy. A clinical genetics consultation can explain what your specific rearrangement means.
Routine NHS screening is the same for everyone: the dating scan and combined screening between 10 and 14 weeks, then the anomaly scan at around 20 weeks. Extra NHS testing usually follows a specific finding, such as a parent carrying a rearrangement or a higher-chance screening result. After recurrent miscarriage, the RCOG advises supportive care from an experienced team, which may include scans for reassurance.
Tell your midwife about the previous result at booking so it is in your notes, and ask your GP about a genetics referral if the result has never been explained to you.
Feeling anxious in a pregnancy after a loss is very common, and early milestones can be hard to enjoy. Miscarriage UK, the working name of the Miscarriage Association, runs a support line (0303 003 6464). Tommy's midwives answer calls free on 0800 0147 800, Monday to Friday, 9am to 5pm. Let your midwife know how you are feeling.
This page explains general options for a pregnancy after a chromosomal miscarriage; it cannot replace advice about your own situation from your midwife, doctor or genetic counsellor. In any pregnancy, heavy bleeding, severe pain, a fever or feeling faint need prompt attention: contact your early pregnancy unit or NHS 111 straight away, or call 999 in an emergency.
Contact
The figures and clinical statements on this page are drawn from the sources below. Guidance evolves — always discuss your individual circumstances with a clinician.
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