Q (Nov 7) What are the long-term effects of taking contraceptive pills? I've been on the pill for four years but decided to stop taking it a year ago. Since I stopped, my skin condition has declined and I have acne again. While on the pill, my skin was much improved. I would like to resume taking the pill but the thought of cancer and all the other side effects I've heard about just puts me off.

A Oral contraceptive (OC) pills are widely used as an effective contraceptive method. Essentially, they contain female sex hormones to be consumed orally to inhibit normal fertility. They come in two main types ? combined oral contraceptive (COC) pills, containing both oestrogen and progestogen, and mini-pills containing only progestogen. Much of the side effects are due to the actions of these hormones on the body system. Below is a summary of the health benefits and risks.

Health benefits
- OCs reduce menstrual cramp in young girls. The cramp is due to the release of a hormone, prostaglandin, which causes the womb to contract. OCs reduce menstrual prostaglandin release and alleviate this symptom in 70-80 per cent of cases.

- In women with heavy menstrual flows, OCs have been used to reduce menstrual flows.

- OCs may relieve some physical and psychological symptoms of pre-menstrual syndrome (breast pain and bloatedness before periods) and improve quality of life.

- OCs reduce the concentration of male hormone in women and thus help in improving skin condition and reducing problems like acne ? as in your case.

- OCs reduce the risk of cancer of the ovary or endometrium (lining of the womb) and colon cancer. The beneficial effects in the case of benign breast disease and for bone health are less clear.

Health risks
About 40 per cent of women who take OCs have minor, transient side effects such as light bleeding between menstrual periods, skipped periods, nausea, and weight change and, bloating during the first three months of use.

More serious problems, though rare, include:
- Increased risk of clots in the deep veins of the legs (deep vein thrombosis). This can lead to a serious life-threatening condition, pulmonary embolism (blood clots in the lung vessels).

- Increased risks of stroke and heart attack. OCs are generally not advisable in women aged 35 and above with pre-existing heart disease, a familial tendency to form blood clots, severe obesity, high cholesterol level, high blood pressure or for those who smoke.

- Increased risk of breast, cervical (neck of the womb) and liver cancer in women. In 2005, the World Health Organisation (WHO), after reviewing published scientific evidence on the pills, stated that OCs are associated with slight increase of these cancers. The risk of breast cancer can continue for up to 10 years after women stop using the pills. For cancer of the cervix, the risk increases the longer women use OCs. It is not certain whether the risk drops after women stop taking OCs.

- Increased incidence of sexual dysfunction. These include decreased frequency of sexual thoughts, increased difficulty in becoming aroused or decreased lubrication, which can make sex painful. Recent studies suggest such effects may continue up to four months after women stop taking OCs.

- Increased risk of developing depression in OC users. Mini-pills are known to worsen the condition of women who are already depressed. Although the health risks are small, it is important for you to have regular check-ups should you continue taking the pills.

DR PETER CHEW, CONSULTANT OBSTETRICIAN AND GYNAECOLOGIST, GLENEAGLES HOSPITAL