Bleeding after vaginal sex

Post-coital bleeding is vaginal bleeding that occurs within 24 hours after sexual intercourse.

Normally you should only have vaginal bleeding when you have a period, but if you have irregular periods, you may not be sure if the bleeding is normal or not. If you are not sure if your bleeding is part of a period, see your GP to discuss this. 

A woman's reproductive system can be divided into upper and lower parts:

• The upper part includes the body of your uterus, your fallopian tubes and your ovaries. Bleeding during your period occurs when the lining of your uterus breaks down as part of a normal monthly cycle.
• The lower part of a woman’s reproductive system is the neck of your womb (cervix), your vagina, and your vulva and labia, which are on the outside of your body. 

It is the lower parts that are usually involved in post-coital bleeding. 

Common causes of post-coital bleeding

Cervical polyps

Polyps occur when some cells in an area grow too much. They can occur in many parts of your body and are usually not serious. Because a polyp is made of cells that have grown abnormally, they can occasionally develop into a cancer. This is how many bowel cancers are thought to start.

Cervical polyps often occur in women with polyps inside your uterus. If the polyps grow too much they can bulge out of the opening of your cervix into your vagina. The cells on polyps are not tough like skin, so if they are rubbed during intercourse they will bleed.

Rarely, cervical polyps develop into cancer of the lining of the womb, called endometrial cancer. Endometrial cancer is not usually detected on a cervical smear but does usually cause irregular vaginal bleeding before it is very advanced, so there is a good chance of a cure. Read more about cervical polyps.

Cervical ectropion

This condition is not serious but is one of the more common causes of post-coital bleeding. Sometimes female hormones cause the cells inside your cervix to grow outward into the part of your cervix that your doctor and nurse can see when they take a cervical smear. This is why sometimes you may have some bleeding after a smear.

Cervical ectropion is similar to cervical polyps except that the cells have not grown too much and are not abnormal, they are just in the wrong place on the outside part of your cervix, where they can be damaged during sex. Read more about cervical ectropion.

Thrush

Occasionally a bad case of thrush can cause bleeding. Usually, there will be a lot of discharge and discomfort as well. You can buy treatment for thrush over the counter at a pharmacy. If you treat thrush but the bleeding doesn’t go away or if you get thrush often, see your GP for a check-up. Recurrent thrush can be a sign of diabetes. Read more about thrush.

Bleeding due to the contraceptive pill or injection

When you first start taking 'the pill' or 'the injection' you can have some irregular bleeding for 2–3 months. Irregular bleeding when on the injection is quite common and is one of the main reasons women stop using this form of contraception.

If you are sexually active and are not planning to become pregnant, there are many effective different types of contraception. Go to Family Planning(external link) or your GP to discuss the choices and find a method of contraception that works for you.

Bleeding caused by sex

Occasionally, sex can cause bleeding from your vagina or vulva. This may occur sometimes the first time you have sex but it should not be heavier than a period or last more than a couple of days.

Although sexual activity does not usually cause damage to your vagina, a rip or tear in your vagina can sometimes occur. Your vagina has a lot of blood vessels just under the surface, so the bleeding can be very heavy and requires management in a hospital.

Bleeding from your vagina after sex is more common if you have gone through menopause and stopped having periods.

• This is often associated with a condition called atrophic vaginitis where the lining of your vagina becomes thinner and more susceptible to infection.
• Women on medications for breast cancer (such as tamoxifen) may also have this condition due to low hormone levels.

Using a water-based lubricant during sex can help prevent bleeding if this is the cause. 

Read more about menopause.

Less common but more serious causes of post-coital bleeding

Cervical cancer

Cervical cancer is a serious condition but if it is treated early it can be cured completely. Fortunately, this cancer can be identified through a smear test before it becomes a serious threat.

The cervical smear test is a very effective way of preventing cervical cancer. The chances of getting cervical cancer if you have has regular smears is very very low.

However, no test is perfect, so even if you have had a recent smear test, you should still see your GP if you have post-coital bleeding. 

Read more about cervical smears and cervical cancer.

Cervical infection

Infection of your cervix is usually a sexually transmitted infection (STI). Some STIs, such as chlamydia and gonorrhoea, are serious and need to be treated. The infection can spread from your cervix to your uterus and fallopian tubes and cause problems getting pregnant. Because they are sexually transmitted, your sexual partner/s will also need to be checked for infection.

Condoms are a very effective protection against infections such as chlamydia and gonorrhoea. They also protect against pregnancy and serious conditions such as HIV. 

Pregnancy

Bleeding in early pregnancy is common. Most women will know they are pregnant soon after missing a period, but many others won't realise they are pregnant for a couple of months. If early pregnancy bleeding occurs around the time you are expecting a period, it is easy to mistake this for a period.

There are several important reasons to find out whether you are pregnant:

• If you are pregnant and plan to continue the pregnancy you may need to change lifestyle behaviours, such as smoking or drinking alcohol, to make sure your baby gets the best possible start in life.
• The treatment of bleeding in early pregnancy is very different to treatment of post-coital bleeding
• Your GP may not want to prescribe some medications if you are pregnant.
• Early pregnancy bleeding can occur with an ectopic pregnancy, which occurs when the pregnancy is growing in a fallopian tube. This is potentially very dangerous.

Read more about pregnancy.  

How is post-coital bleeding diagnosed?

To find out the cause of the bleeding, your GP will need to ask you some personal questions about your sexual activity. These questions can be a bit embarrassing but your GP talks about this kind of thing all the time. The more information you can give the easier it will be for them to find out what's going on. 

Your GP will also need to find out about:

• what contraception you are using
• any other medications you are on
• when you last had a cervical smear.

If you are not seeing your regular GP it can be really helpful if you take along your medications such as 'the pill' if you are using it.

Tests and procedures

There are some common tests and procedures that your doctor may also ask for, such as the following:

• A urine sample to check for pregnancy or urine infection.
• A vaginal examination to look for causes of bleeding in your vagina or cervix. This examination is the same as having a smear test.
• A smear test might be repeated and tests for infection can be done at the same time.
• Occasionally your GP may also do a test called a pipelle. This is done at the same time as a smear test, but using a very thin plastic tube to collect a sample of the lining of the uterus. The GP will want to know whether you are pregnant before this test.
• An ultrasound scan, especially if your pregnancy test is positive, the examination suggests there is a problem with your uterus or ovaries, you are over 45 years old or if there is a family history of certain types of cancer.

What is the treatment for post-coital bleeding?

Treatment for post-coital bleeding will depend on what the cause is. Your doctor will advise you on the best course of action once a diagnosis has been made. 

Wan YL, Edmondson RJ, Crosbie EJ. Intermenstrual and postcoital bleeding(external link)(external link) Obstetrics, Gynaecology and Reproductive Medicine. 2015;25:4:107-12.

Periods
Heavy periods
Painful periods
Sexual health overview
Menopause

Clinical update

The following information about post-coital bleeding(external link)(external link) is taken from Auckland Regional HealthPathways, accessed November 2019:

Post-coital bleeding refers to vaginal bleeding that is noted within 24 hours of vaginal intercourse, excluding the onset of expected menses.

Red flags

Abnormal appearance of cervix, even if the cervical smear is normal.

Assessment

1. Consider these causes:
   • Cervix – ectropion, cervicitis, polyps, carcinoma (high risk if poor smear history), pelvic organ prolapse
   • Infection – herpes simplex, condylomata accuminata, chlamydia
   • Trauma – foreign bodies, sexual abuse
   • Atrophic vaginitis
2. Check previous gynaecological and smear history. Perform smear if it is due.
3. Carry out a speculum and bimanual examination to exclude overt cervical malignancy.
4. Carry out STI screen.
   

Clinical resources

Chronic pelvic pain in women(external link)(external link) BPAC, NZ, 2015
Vulvovaginal health in premenopausal women(external link)(external link) BPAC, NZ, 2011
Updated guidelines for cervical screening in NZ(external link)(external link) National Screening Unit, NZ, 2016
Cervical screening guidelines(external link)(external link) National Screening Unit, NZ, 2014
How to increase the uptake of cervical screening – a profile of success(external link)(external link) BPAC, NZ, 2013