Irregular or unscheduled bleeding


Many women struggle with both the heaviness, and the timing, of their bleeding. The ideal '28 day cycle' seems pretty elusive for some! There are a number of causes of irregular bleeding, and what investigations need to be done depend a bit on the age and fertility plans of the patient.


Common causes can include:

  • Ectropion. Sometimes the cervix can be a little 'raw', and can become fragile and bleed after intercourse or occasionally at random times. Colposcopy is used to diagnose and treat this area.
  • Endometriosis. The most common symptoms are painful periods, painful sex, pain before or during a bowel motion, and infertility. Sometimes the bladder, or very rarely other areas in the abdomen, can be affected. In some women, spotting leading up to the actual 'period' is a sign of endometriosis.
  • Infection. Cervical or vaginal infection with chlamydia and other bacteria may cause bleeding, discharge and pain. In some cases the infection can spread to the womb and fallopian tubes, which can lead to severe illness (pelvic inflammatory disease) or infertility. It is very important that infection is ruled out in cases of irregular bleeding; in most cases this is already done by the GP before we see the patient.
  • Instability of the lining of the womb – commonly due to fluctuations in hormone levels on the oral contraceptive pill, the contraceptive implant (Jadelle) or intrauterine devices (Mirena, Jaydess). This is sometimes called 'break-through' or 'unscheduled' bleeding. It is a common reason for stopping or changing contraception, but in most cases this will settle with time. There are various strategies that can be tried, such as adding extra estrogen hormone to balance the progesterone in the contraceptive, or an antibiotic (doxycycline) to help with repair of the lining.
  • Ovarian cysts. Some types can cause irregular bleeding, including haemorrhagic cysts and functional cysts.
  • Perimenopause. As women approach menopause, the number of healthy eggs in the ovaries is declining. Some cycles an egg won't mature and be released, leading to a missed period, while in others the higher hormone levels driving the ovaries leads to a shorter cycle. This unpredictability of the pattern, along with heavy and light cycles, can be very disruptive and many women seek advice at this stage to manage their bleeding. There are a range of options in this situation; see also the section on heavy periods.
  • Polycystic ovarian syndrome (PCOS). This usually causes infrequent (4-5/year) and sometimes heavy periods. When the bleeding is so infrequent it tells us that the ovaries are not making an egg (ovulating) with any predictability. This makes getting pregnant very difficult, but luckily there are effective treatments. PCOS is associated with other medical issues, such as high blood pressure and diabetes, and so needs to be carefully managed throughout a woman's lifetime.
  • Polyps. These are usually small (5-20mm) soft growths from the lining of the womb or the cervix. Sometimes the end can become ulcerated or break down and cause bleeding. It is rare for a polyp to be cancerous but it can occur and therefore if there are symptoms, if the polyp looks suspicious or you are around or after menopause we would suggest removal.
  • Pregnancy. Early pregnancy needs to be ruled out as a cause in anyone who is sexually active and still having periods.

What to do

With such a range of possibilities it can be tricky to make a quick diagnosis. Often blood tests, swabs and a scan will be needed to investigate the cause. Occasionally a biopsy from the lining of the womb, or a surgical procedure such as hysteroscopy, colposcopy or laparoscopy will be necessary.

How we can help

If you are experiencing irregular or unscheduled bleeding and would like to talk to us about how we can help, please feel free to contact us. You can also request an appointment online.

Further information



An ectropion is when the inside of the cervix (endocervix) becomes everted on to the outside of the cervix. The endocervix is more fragile, and can bleed with contact. Find out more


Endometriosis is a common disorder that affects many women in New Zealand. It occurs when endometrial tissue, which should only be found in the uterus, also grows outside the uterus, such as on ovaries or the bowel. This can be very painful and is why women with endometriosis usually have pain around the same time as their period. Find out more


An infection is the invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body. An infection is a cause that is always considered in women with abnormal bleeding. Find out more

Instability of the lining of the womb

Instability of the lining of the womb is the most common cause of postmenopausal bleeding. It is caused by low estrogen levels, and the tissues become atrophic. The tissue then becomes prone to bleeding and spotting. Find out more

Ovarian cysts

Ovarian cysts are very common. There are a number of different types, with different symptoms and a range of treatments. In many cases, they will cause no problems at all, and resolve on their own without intervention. Find out more


Perimenopause - the menopause transition - starts a few years prior to menopause itself, which is when a woman’s menstrual periods stop, and no further eggs are released from the ovaries. Find out more

Polycystic ovarian syndrome (PCOS)

PCOS is a very common disorder in women. Symptoms vary, and can include irregular or absent periods, excess hair, weight gain or difficulty falling pregnant. Find out more


Polyps are common benign growths. They can occur in the uterus (endometrial polyps), cervix (cervical polyps) or vagina (vaginal polyps). Polyps can cause irregular or unscheduled bleeding. Find out more


Most pregnancies happily need care, attention and support only. The role of a midwife and obstetrician is to guide through the routine and normal parts of pregnancy, labour and postnatal care. Also importantly to recognise when intervention is required, when normal has become or is becoming abnormal. Find out more


Ectropion treatment

Ectropion is common, and treatment is generally not required. When bleeding is persistent and troubling, women may consider ablative treatment such as cautery (electrosurgery). Colposcopy may also be used to diagnose and treat this area.

Endometriosis resection

This entails keyhole surgery, where a camera is placed through the bellybutton to view the pelvis. The abdomen and pelvis are carefully explored, and abnormal tissue removed. Cysts may also be removed from the ovaries. Find out more


A hysterectomy is when a woman's uterus is removed. This may be because methods to stop heavy bleeding are not successful, side effects of medications are intolerable, fibroids are problematic or endometriosis is severe enough that a more permanent solution is required. Find out more


A mirena is a small plastic device placed inside the uterus with small strings extending out through the cervix. In addition to being used for contraception, mirena can be used to treat endometriosis. Find out more

Treatment for infections

If an infection is the cause, treatment with antibiotics is required. This is generally given orally, but if an infection is severe, antibiotics given intravenously may be required.

Treatment for instability of the lining of the womb

Treatment is generally not required. Vaginal estrogen treatment may be beneficial. It is important to rule out other causes of bleeding such as abnormal cells within the uterus, or cancer of the uterus. This may necessitate a biopsy.

Ovarian cyst removal

This entails keyhole surgery, where a camera is placed through the bellybutton to view the pelvis. The abdomen and pelvis are explored, and the cyst carefully removed from the ovary. The ovary may be stitched to allow it to heal better. Find out more

Treatment for perimenopause

Treatment is dependent on what symptoms a woman is experiencing. Hormone replacement therapy may be an appropriate treatment for symptoms such as hot flushes. There are also non-hormonal options.

Treatment for PCOS

Treatment of PCOS depends on what symptoms are causing problems. Women with PCOS may need treatment for issues such as sub fertility, diabetes and heart disease.


A hysteroscopy is a common gynaecological procedure, placing a thin camera through the cervix to evaluate the inside of the uterus (the endometrial cavity). This may be as an investigation or a treatment. Find out more


Aceso provides private obstetric services for those women having a planned elective caesarean section. We also offer Down syndrome screening, vaccination(s) during pregnancy, and ultrasound scanning. Find out more

Endometrial ablation

A treatment for heavy menstrual bleeding that involves a general anaesthetic and a controlled cauterisation of the endometrium (the area that is shed during menstruation). It may be a suitable alternative to hysterectomy, but has higher rates of recurrence. Find out more