Bleeding between periods: causes and when to see a gynaecologist

Common causes

Hormonal contraception. Breakthrough bleeding is the most frequent cause of intermenstrual spotting, 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 persists beyond 3 months on a new contraceptive, discuss it with your doctor; a different formulation may suit you better.

Ovulation spotting. Some women notice light spotting around the middle of their cycle (days 12-16), corresponding to ovulation. This is caused by the brief oestrogen dip that occurs when the follicle releases the egg. It is normal, usually lasts a day or two, and does not need treatment.

Cervical ectropion. Cells from the inner cervical canal extending onto the outer cervix. Common in younger women and those on the combined pill. The cervix bleeds easily on contact (during sex or a smear test) and can also cause spotting between periods. Not harmful, treatable with cauterisation if bothersome.

Cervical or endometrial polyps. Small, benign growths on the cervix or inside the womb that bleed intermittently. Polyps are very common and are not cancerous. They can be identified 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), leading to spotting. If you have had a new sexual partner or unprotected sex, a sexual health screen is worth doing.

Fibroids. Non-cancerous growths in or on the womb wall. Submucosal fibroids (those growing into the womb cavity) are particularly likely to cause intermenstrual bleeding and heavy periods. Identified on pelvic ultrasound.

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

Perimenopause. As you approach menopause, fluctuating hormone levels make your cycle unpredictable. Periods may come closer together, further apart, or be interspersed with spotting. If you are over 40 and your cycle has changed, a hormone panel can clarify 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 spotting mid-cycle, particularly if you can link it to ovulation or a missed pill, does not usually need investigation.

Book an appointment if:

• The bleeding happens repeatedly 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 (not just spotting).
• You have pelvic pain alongside the bleeding.
• You are over 40 and this is a new pattern.
• You are on the coil and the bleeding has not settled after 6 months.

What the investigation involves

A gynaecological assessment for intermenstrual bleeding 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 Mr Naoum, Consultant Gynaecologist.

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

Postmenopausal bleeding

If you have gone through menopause (12 months without a period) and then experience any vaginal bleeding, no matter how light, see a gynaecologist. Postmenopausal bleeding is a specific clinical scenario that always requires investigation.

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

Do not assume postmenopausal bleeding is "just hormonal." It may well be, but the only way to know is with an assessment.