What counts as a miscarriage

The NHS defines it as the loss of a pregnancy before 24 weeks. Early miscarriage means the first 14 weeks in the NHS's framing, and the first three months in the RCOG's; late miscarriage means roughly 14 to 23 weeks.

The RCOG is blunt about how common early miscarriage is: "In the first 3 months, one in five women will have a miscarriage, for no apparent reason, following a positive pregnancy test." It also notes that many happen before a period is even missed.

On cause, the RCOG says that in most cases no reason can be given, and that the most common cause is thought to be a problem with the pregnancy's chromosomes. It adds two things people ask about constantly: "There is no evidence that stress can cause a miscarriage. Sex during pregnancy is not associated with early miscarriage."

There is no reliable published table of miscarriage risk week by week that we are willing to reproduce here. The numbers circulating online are mostly derived from small or unrepresentative datasets and vary wildly. If you want a figure for your own situation, ask the clinician who has scanned you.

What it feels like

The NHS lists the main symptom as vaginal bleeding before 24 weeks, and describes the range: spotting, light bleeding needing a pad, or heavy bleeding that soaks through a pad. Alongside that it lists pain and cramping low in the tummy, pink, grey or white lumps coming from the vagina that may look or feel stringy, and fluid suddenly coming from the vagina.

Sometimes there is nothing at all. The NHS: "Sometimes you may have no symptoms and you'll only find out you've had a miscarriage at a pregnancy scan. This is called a missed miscarriage."

The NHS also makes the point that bleeding and tummy pain in pregnancy "can be caused by other things and are not always serious" — but that being worried is itself a good enough reason to call.

When to get help now

The NHS says to call 999 (or your local emergency number — 911 in the US and Canada, 000 in Australia, 111 in New Zealand) if you are pregnant, have vaginal bleeding, and:

severe pain in your tummy — pain that stops you doing daily tasks or focusing
pain in your shoulder
feeling sick, faint or dizzy, or losing consciousness
heavy bleeding — soaking a period pad soon after putting it on

Shoulder pain in that list is there because of ectopic pregnancy, not because of miscarriage. Take it seriously.

Get urgent, same-day advice for lighter bleeding or spotting, unusual discharge, or fluid leaking. Call your maternity unit if you have one. If you are under 20 weeks, an early pregnancy unit may be able to see you — the NHS says the contact details are on your local trust website or in your maternity notes. Otherwise call your local urgent care line.

How it is diagnosed

Usually with an ultrasound scan, often transvaginal because it gives a clearer image. The RCOG notes that neither a transvaginal nor an abdominal scan increases your risk of miscarriage.

NICE sets out why a single scan sometimes is not enough, and it is worth knowing before you are told to come back: if the crown-rump length is less than 7.0 mm with no visible heartbeat, or the mean gestational sac diameter is less than 25.0 mm with no visible fetal pole, a second scan should be performed a minimum of 7 days after the first before a diagnosis is made. At or above those measurements, NICE still recommends a second opinion or a repeat scan at least 7 days later.

NICE also tells clinicians to say out loud that "the diagnosis of miscarriage using 1 ultrasound scan cannot be guaranteed to be 100% accurate". The repeat scan is not indecision. It is the safeguard.

The three options

The NHS states the fact that underlies all of them: "A miscarriage cannot be stopped once it has started."

Waiting (expectant management)

NICE recommends expectant management for 7 to 14 days as the first-line strategy after a confirmed miscarriage, unless there is a reason not to — increased risk of haemorrhage, a previous traumatic pregnancy experience, a bleeding disorder or inability to have a transfusion, or signs of infection. The RCOG says this works for about 50 in 100 people who choose it, that bleeding can take time to start and may continue for up to 3 weeks, and that it can be heavy and crampy.

Medicine (medical management)

For a missed miscarriage NICE recommends 200 mg oral mifepristone followed 48 hours later by 800 micrograms of misoprostol, unless the sac has already passed. For an incomplete miscarriage NICE recommends a single 600 microgram dose of misoprostol (800 micrograms may be used to align local protocols), and specifically says not to use mifepristone for incomplete miscarriage. Pain relief and anti-sickness medicine should be offered to everyone having medical management. NICE says to contact your service if bleeding has not started within 48 hours of the misoprostol.

A procedure (surgical management)

NICE says that where clinically appropriate you should be offered a choice between manual vacuum aspiration under local anaesthetic in an outpatient or clinic setting, and surgical management in theatre under general anaesthetic. The RCOG puts the success rate at about 95 in 100, and lists the small risks: heavy bleeding, infection, or damage to the womb.

After either expectant or medical management, NICE says you should be given a urine pregnancy test to do at home 3 weeks later, and told to return if it is positive.

Afterwards

The RCOG says to expect vaginal bleeding for 1 to 2 weeks, heavy like a period for the first day or so, then lessening and turning brown, and to use pads rather than tampons because of infection risk. Your next period is usually in 4 to 6 weeks — but ovulation happens before that, so you can be fertile in the first month.

The NHS advises resting if you need to, paracetamol for pain, and avoiding sex until symptoms have gone because of infection risk. It also says to talk to a GP if you have had 3 or more miscarriages, as you will usually be referred for tests.

Emotionally, the NHS is clear that everyone experiences this differently, that you may feel physically better within days or weeks but that "sometimes it takes longer to come to terms with what's happened emotionally", and that counselling can be offered or requested.

Where to get support

Miscarriage UK, formerly the Miscarriage Association, runs a staffed support line and written information on every type of loss. Tommy's has a midwife line and support sections including second trimester loss. In Ireland, the HSE's miscarriage pages set out the local pathway. In the US, ACOG's early pregnancy loss information covers the same options under American practice. Your own early pregnancy unit can also refer you.

Miscarriage: What Actually Happens