Oral contraceptive pills prevent pregnancy by stopping ovulation. Photo: AFP
I am a woman who is thinking of going on oral contraceptives. At the same time, I heard that they have some side effects. What actually constitutes oral contraceptives?
The birth control pill that you know is also commonly known as the combined oral contraceptive pill. It is called thus because it is a combination of two of your reproductive hormones – an oestrogen (formulated in the pill as ethinylestradiol) and a progesterone (usually progestin in the pill.)
They are oral, which means you take them by mouth every day. They mimic or “fool” your body into thinking it is pregnant, therefore you won’t ovulate.
As a result, you won’t get pregnant because there is no “egg” or ovum released from your ovaries.
How does the pill really work?
Oral contraceptives prevent pregnancy by stopping ovulation, as mentioned above.
The synthetic oestrogen in the pill prevents your own oestrogen from peaking in the middle of your menstrual cycle, a peak that would normally stimulate your pituitary gland in your brain to produce other hormones called follicle stimulating hormone (FSH) and luteinizing hormone (LH).
The FSH and LH hormones normally result in an egg being released from one of your ovaries. Therefore, no egg is released.
The synthetic progestin in the pill also stops the pituitary gland from producing LH. Additionally, it makes the uterine (womb) lining extremely thick and impenetrable to sperm, as well as being inhospitable to a fertilised egg.
But if the pill mimics pregnancy, how then does a woman on the pill get menstrual bleeding? My sister is on the pill, and she has regular menstruation every month.
Most brands of combined pills are packaged in either a 28-day pack or a 21-day pack.
For the 21-day packet, you consume a pill daily for three weeks, followed by a week of no pills. For the 28-day packet, you consume a pill daily for 21 days, followed by a week of placebo or sugar pills.
Because of this fourth week of no oestrogen/progesterone stimulation, you will have a withdrawal bleed sometime during the placebo week, and you will still be protected from pregnancy during this week.
The manufacturers of the pills designed them this way because a woman is always relieved when she has her period (to ensure she is not pregnant) as opposed to not having her period completely (which always makes her worry whether or not she is pregnant).
There are other newer packs, such as a 24-day pack, which works pretty much the same way.
There are several types of oral contraceptive pills. The most common one is the combined one, but there are also progestin-only pills.
What are progestin-only pills? What advantage do they have over combined oral contraceptives?
Progestin-only pills have progesterone but no oestrogen. They are also called the mini-pill.
The advantage they have over combined oral contraceptive pills are that they are for women who cannot take oestrogen for any reason at all.
Unlike combined oral contraceptives, the progestin-only pill works primarily through progesterone actions – thickening the mucous between your uterus and your vagina. Sperm cannot penetrate this thick mucous to reach your egg.
This progestin-only pill also works like a combined oral contraceptive pill in fooling your body into thinking that it is pregnant.
This type of pill is for you if:
• You are breastfeeding because it will not affect your milk production, whereas oestrogen-containing pills might reduce the amount of milk your breasts can produce.
• You are older than 35, smoke, have high blood pressure, or have a tendency for blood clots. Therefore, it is safer for you to use.
• You can’t take certain side effects of the combined pill. This progestin-only pill will probably not give you the side effects of oestrogen.
Which brings me back to my original worry. Are oral contraceptives safe?
They have a good safety profile.
They have been in use since the 1960s, and they are being used by over 100 million women worldwide. They were considered the catalyst for the sexual revolution in the 1960s.
They are extremely effective. Nevertheless, some women experience side effects with them, such as breakthrough bleeding in the middle of the menstrual cycle, bloating, swelling and weight gain due to water retention.
There is also a higher risk of blood clots forming in your blood vessels, and a very slight breast cancer risk increase – which goes away five to 10 years after stopping the pill.
But when you calculate the risks of getting an unwanted pregnancy and all the complications of an illegal abortion, the risks of the oral contraceptive pill are far, far lower. Therefore, they are still medically recommended for most of the female population who desire contraception.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, e-mail firstname.lastname@example.org. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.