Bleeding between periods: causes and when to see a gynaecologist

Common causes

Hormonal contraception. Breakthrough bleeding is the most frequent cause of spotting between periods, particularly in the first 3-6 months of starting or changing the pill, implant, injection or hormonal coil. If you are on the combined pill and have missed a dose or taken it late, spotting is expected. If bleeding carries on beyond 3 months on a new contraceptive, talk to your doctor, because a different formulation may suit you better.

Ovulation spotting. Some women notice light spotting around the middle of their cycle (days 12-16), when they ovulate. It comes from the brief dip in oestrogen as the follicle releases the egg. It is normal, usually lasts a day or two, and needs no treatment.

Cervical ectropion. This is when cells from the inner cervical canal extend onto the outer cervix. It is common in younger women and those on the combined pill. The cervix bleeds easily on contact, during sex or a smear test, and it can also cause spotting between periods. It is harmless, and it can be treated with cauterisation if it bothers you.

Cervical or endometrial polyps. These are small, benign growths on the cervix or inside the womb that bleed on and off. Polyps are very common and non-cancerous. They can be found on ultrasound or by direct examination, and removed if they are causing symptoms.

Infections. Chlamydia, gonorrhoea and other STIs can cause cervicitis (inflammation of the cervix), which leads to spotting. If you have had a new sexual partner or unprotected sex, a sexual health screen is worth doing.

Fibroids. These are non-cancerous growths in or on the womb wall. Submucosal fibroids, the ones growing into the womb cavity, are particularly likely to cause bleeding between periods and heavy periods. They show up on a pelvic ultrasound.

Endometriosis. This can cause spotting between periods, particularly alongside pelvic pain, painful periods or pain during sex.

Perimenopause. As you approach the menopause, fluctuating hormone levels make your cycle unpredictable. Periods may come closer together or further apart, with spotting in between. If you are over 40 and your cycle has changed, a hormone panel can show where you are.

Pregnancy. Early pregnancy (implantation bleeding), ectopic pregnancy and miscarriage can all cause bleeding. If there is any chance you could be pregnant and you are bleeding, take a pregnancy test and seek medical advice.

When to see a gynaecologist

Occasional mid-cycle spotting that you can link to ovulation or a missed pill usually needs no investigation.

Come and see us if:

• The bleeding has come back over more than two or three cycles.
• You are bleeding after sex as well as between periods.
• You have any bleeding after menopause.
• The bleeding is heavy, rather than spotting.
• You have pelvic pain alongside the bleeding.
• You are over 40 and this is a new pattern.
• You have a coil and the bleeding is still there after 6 months.

What the investigation involves

A gynaecological assessment for bleeding between periods typically includes:

• A detailed history of your bleeding pattern, cycle and contraception.
• A speculum examination to look at the cervix for ectropion, polyps or inflammation.
• A smear test if you are due one.
• Swabs for infection if an STI is possible.
• A pelvic ultrasound to assess the womb lining, look for polyps or fibroids, and check the ovaries.

At our clinic, the consultation, examination and ultrasound can all be done in a single appointment with Dr Naoum, Consultant Gynaecologist, for £450 in total. Request the ultrasound when you book so it can be done on the same day.

If the ultrasound shows a polyp or thickened womb lining, a hysteroscopy may be recommended as a next step.

Postmenopausal bleeding

If you have gone through the menopause (12 months without a period) and then have any vaginal bleeding, however light, see a gynaecologist. Postmenopausal bleeding is a specific clinical situation that always needs investigating.

The most common cause is vaginal atrophy. Other causes include endometrial polyps and, less commonly, endometrial hyperplasia or cancer. A pelvic ultrasound measuring the thickness of the womb lining (endometrium), combined with an examination, finds the cause in most cases. If the lining is thickened, a biopsy may be recommended.

It may well be "just hormonal", and an assessment is how you find out for sure.