Early pregnancy - why am I bleeding?
Is it normal to bleed in the early weeks of pregnancy? And what should you do if it happens to you? With the help of an expert obstetrician, we look at what the bleeding could be, whether it's important if the bleeding is light or heavy, how long it could last for – and what you should do if it happens to you
Last reviewed by Dr Philippa Kaye in August 2023
Vaginal bleeding in early pregnancy is, obviously, worrying and upsetting. The first thing to know is that it's quite common – studies¹ suggest it happens to up to 24% of us in the 1st 12 weeks of pregnancy (and to a much smaller number from 12 to 24 weeks). And the next is that, though you should always get it checked out, it doesn't necessarily mean the worst.
"Bleeding in the 1st trimester is not that unusual" says Patrick O'Brien, consultant obstetrician at University College Hospital, London. "Many women fear it's going to lead to a miscarriage but that's not necessarily the case. It can do, of course, but for most women the bleeding will settle down and stop."
So, if you're in the early stages of pregnancy and you're bleeding, what's going on? There are lots of possible causes of bleeding and spotting in early pregnancy, ranging from minor to more serious. Here's a rundown of what it could be, how light or heavy the bleeding might be, how long it could last for – and what you should do if it happens to you...
What could be causing blood loss in early pregnancy?
It could be… implantation bleeding
Some (but not all) pregnant women experience a small bleed 6 to 12 days after conception – so just before the time your period would probably have been due. This happens as your fertilised egg implants in the lining of your womb and usually appears as light, brownish spotting.
It could be… hormonal bleeding
Hormonal or 'breakthrough' bleeding can happen at about 4 to 8 weeks into pregnancy – so round about the time your period would have been due). It's more common than you'd think – and a reason some women do not realise they are pregnant for a while. This sort of bleeding is usually light and generally settles by week 13, when your placenta should have developed sufficiently to produce all the hormones needed to sustain pregnancy.
It could be… cervical erosion
This rather scary-sounding medical term actually describes a condition that is quite harmless and painless. It's sometimes also called cervical ectropion or ectopy, and it's where some of the delicate cells that normally line the inside of your cervix migrate and move to the outside your cervix. (This sometimes happens when you're not pregnant and you take the Pill, too). As these cells are fragile, they can bleed easily (though harmlessly and painlessly). This kind of bleeding is usually light or looks like spotting – and can sometimes happen after sex.
It could be... a cervical polyp
A polyp is a growth of tissue that can occur in various places on the body, including the cervix, whether you are pregnant or not. They are usually small, benign (non-cancerous) and symptomless. However, cervical polyps are fragile and, if they have blood vessels in them, they can cause some spotting or bleeding – at any stage in your pregnancy.
It could be… a subchorionic haematoma
A subchorionic haematoma is the medical term for bleeding, or a build-up of blood, between the wall of your uterus and the sac of membranes which are protecting your developing baby (or, later in pregnancy, underneath the placenta itself). The bleeding is usually light and accompanied by abdominal cramps. It's one of the most common causes of bleeding in weeks 10 to 20² and is thought to account for 11% of all cases of vaginal bleeding in pregnancy. That said, it's usually nothing to worry about – although, once diagnosed, your doctor or midwife will want to discuss it with you.
It could be… an infection
Any infection of your vagina or cervix (including sexually transmitted diseases, such as genital herpes, chlamydia or gonorrhoea) can cause bleeding. (And will, obviously, need to be treated.)
It could be… an ectopic pregnancy
Bleeding or brown, watery discharge in the first 12 weeks that's accompanied by strong, painful cramping in your lower tummy – and maybe also a pain in the tip of your shoulder – may signal an ectopic pregnancy. This can happen when your fertilised egg remains stuck in 1 of the Fallopian tubes that connect your ovaries to your womb. It's a potentially dangerous condition but it is also very rare (affecting about 2% of pregnancies).
It could be… the start of a miscarriage
Yes, sadly, blood loss in early pregnancy can be a sign of miscarriage, especially if the blood's red and the flow is heavy or you’re also cramping and in pain. But it's not the only reason you could be bleeding, as we've shown from the examples above. And bleeding doesn't always happen before a miscarriage: it is possible to have a miscarriage without bleeding.
What should I do if I’m bleeding in early pregnancy?
"As a general rule," says Patrick O'Brien, "the heavier the bleeding, the more worrying it might be."
But any bleeding in pregnancy should always be checked out – with a call to your midwife or GP – whatever you think the cause might be.
When you call, try to give as much information as you can about how much you're bleeding, and what colour the blood is.
After your call, you may be referred to a local early pregnancy unit for assessment and a scan. But, if it's very early on in your pregnancy – before 6 or 7 weeks – and you're not in pain, you may be told to wait to see if the bleeding stops of its own accord. That's horrible, we know, but, unfortunately, before about 6 weeks of pregnancy, an ultrasound scan wouldn't be able to detect your baby's heartbeat, so there would be no way to check what's happening with your baby.
We know how difficult having to wait like this can be. If this happen to you, may find it helps to share your experience with someone else: you could call the Miscarriage Association's helpline on 01924 200799 (open Monday to Friday, 9am to 4pm). They also run a Facebook page, a forum and an online Live Chat.
If you are further on in your pregnancy and are asked to come to your local Early Pregnancy Unit, your doctor or midwife is likely to examine you – or refer you to be examined – with an (internal) ultrasound scan and some blood tests, and maybe a vaginal swab, if an infection is suspected.
It may well be that nothing concerning is found, and you will be sent home and told only to return if the bleeding gets heavier and/or the pain gets worse. You may, at this point, hear the term 'threatened miscarriage': this means that, although you're bleeding or have been bleeding, there is no sign – right now – that you're having a miscarriage. Many women who have a 'threatened miscarriage' go on to have a healthy baby.
If, however, doctors find evidence that something is wrong with your baby, then, unfortunately, this is a 'confirmed miscarriage' and doctors will talk you through your options about what happens next.
If you're bleeding and you've previously had a miscarriage
If you're experiencing vaginal bleeding and have previously had at least one miscarriage – and, when you're given an ultrasound scan, a pregnancy is seen in your womb, you will now be offered progesterone treatment until you're 16 weeks pregnant.
This treatment is not recommended for everyone: you won’t be offered it if you have had vaginal bleeding in early pregnancy before but haven’t had a previous miscarriage, or if you have had a previous miscarriage/s but haven’t had bleeding in this pregnancy.
If you're having the progesterone treatment and you have concerns, the bleeding becomes very heavy or you have other symptoms such as severe pain, feeling dizzy, lightheaded or unwell, do please seek urgent medical advice.
About our expert: Patrick O'Brien
Pat O'Brien has been a Consultant & Honorary Senior Lecturer in Obstetrics and Gynaecology at University College London Hospitals since 1999. He has served as Vice President of the Royal College of Obstetricians and Gynaecologists (RCOG). He specialises in high-risk obstetrics and fatal monitoring and has a particular interest in the medical complications of pregnancy.
1. Patterns and predictors of vaginal bleeding in the first trimester of pregnancy. Hasan et al. Ann Epidemiol. 2010 Jul; 20(7): 524–531. doi: 10.1016/j.annepidem.2010.02.006
2. Subchorionic Hemorrhage. Bondick et al. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
Pic: Getty Images
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