A friend of mine recently expressed concern about some of the new oral contraceptive pills being sold on the United States market. There are new pills which involve no periods or very few periods in a year. She was concerned about the manipulation of the female hormones by these pills as opposed to the traditional birth control pills which allows for a monthly 'period'. I realised that she, like many of my patients, hold a common misconception. They mistook the monthly bleeding on the pill for a regular period.

The birth control pills available in Jamaica consist of two types of hormones, a progestin and an oestrogen. Usually a woman will take one pill daily for 21 days followed by seven days without any pills. The role of the progestin is to prevent a woman from ovulating and to thicken the mucus of the cervix (making it more difficult for sperm to pass through). The role of oestrogen is to prevent the bleeding from the lining of the womb and to prevent the development of the follicle in which the egg is formed. A woman usually has a 'period' during the seven pill-free days. This period is, in fact, a withdrawal bleed due to the absence of the oestrogen component.

The new pills

The birth control pill Seasonale involves taking hormones for 84 days followed by seven pill-free days allowing for a withdrawal bleed. An even newer type of the oral contraceptive pill called Lybrel involves taking a pill daily for the entire year and menses are avoided. Neither of these formulations are currently available in Jamaica.

However, the hormones in Seasonale and Lybrel are of the same type as those in formulations such as Nordette or Minigynon which are available locally. If a woman is taking a locally available birth control pill and desires to avoid her menses, she may take two consecutive packs of pills and avoid the pill-free week. However, this is sometimes associated with breakthrough bleeding or spotting. All contraceptives have risks and benefits and a woman should discuss these concerns with her physician before starting a contraceptive.

Response to reader

Dear Dr Rainford,

How are you? I read an article of yours and decided to email you. I got the contraceptive injection in April which lasted for three months. I did not take any after that and I noticed until now that my period hasn't yet come. I did a couple of pregnancy tests but they turned up negative. I feel sick and sometimes sleepy and my breasts are extremely tender.

Could I be pregnant even if the tests show negative? What could be the cause?

Dear Reader,

I assume from your letter that the contraceptive you received was depomedoxyprogesterone acetate, DMPA (commonly sold locally as Depoprovera). This contraceptive can result in amenorrhoea (absence of periods) and there may be a delay in the return of your periods even after you have stopped using the medication.

Studies have shown that the medication is detectable in your blood for up to nine months after the last injection and it may take up to a year for you to ovulate again. It is unlikely that you are pregnant if your tests were performed correctly, but this can be easily confirmed by requesting a blood pregnancy test from your doctor. Women on DMPA may experience fatigue and even less commonly breast tenderness and nausea. However, I do advise you to consult your doctor for a proper medical evaluation of your symptoms.

Dr Monique Rainford is a consulting obstetrician and gynaecologist; email: yourhealth@gleanerjm.com.