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Fertility health centre

Irregular periods and getting pregnant


WebMD Medical Reference
Medically Reviewed by Dr Rob Hicks

Having irregular periods can make it harder to get pregnant.

Having irregular periods, no periods, or abnormal bleeding can indicate that a woman is not ovulating, a condition doctors call anovulation.

Although anovulation can usually be treated with fertility drugs, it is important to rule out other conditions that could interfere with ovulation, such as thyroid conditions or abnormalities of the adrenal or pituitary glands. After initial screening, your GP will be likely to send you to a specialist obstetrician/gynaecologist for further investigations.

Getting pregnant when you have ovulation problems

Once your doctor has ruled out other medical conditions, he or she may prescribe fertility drugs to stimulate your ovulation.

The drug contained in clomifene is often a first choice because it's effective and has been prescribed to women for decades. Unlike many infertility drugs, it also has the advantage of being taken by mouth instead of by injection. It is used to induce ovulation and to correct irregular ovulation by increasing egg production by the ovaries. Clomifene induces ovulation in most women with anovulation.

These fertility drugs sometimes make the cervical mucus "hostile" to sperm, keeping sperm from swimming into the uterus. This can be overcome by using artificial insemination to fertilise the egg.

Depending on your situation, your doctor may also suggest other fertility drugs that stimulate follicles and egg development in the ovaries. These are the so-called "super-ovulation" drugs. Most of these drugs are administered by injection just under the skin. Some of these hormones may over stimulate the ovaries (causing abdominal bloating and discomfort) so your doctor will monitor you with frequent vaginal ultrasounds and blood tests to monitor oestrogen levels. About 90% of women ovulate with these drugs and between 20% and 60% become pregnant.

Polycystic ovary syndrome (PCOS)

A common ovulation problem that affects about 5% to 10% of women in their reproductive years is polycystic ovary syndrome (PCOS). PCOS is a hormonal imbalance that can make the ovaries stop working normally. In most cases, the ovaries become enlarged and appear covered with tiny, fluid-filled cysts. Symptoms include:

  • No periods, irregular periods, or irregular bleeding
  • No ovulation or irregular ovulation
  • Obesity or weight gain (although thin women can develop PCOS)
  • Insulin resistance (an indicator of diabetes or risk of diabetes in the future)
  • High blood pressure
  • Abnormal cholesterol with high triglycerides
  • Excess hair growth on the body and face (hirsutism)
  • Acne or oily skin
  • Thinning hair or male-pattern baldness

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