Nervous your contraceptive method might not be effective? Here’s everything you need to know.
Thinking about going on the pill, or anxious that it might not work effectively? The contraceptive pill is a highly effective method of contraception – that is, if you make sure you take it correctly. But how can you maximise your chances of the pill working properly?
Dr Geetha Venkat from the Harley Street Fertility Clinic looks at the likelihood of getting pregnant while taking the oral contraceptive pill:
How does the contraceptive pill work?
There are two types of oral contraceptives, the combined hormonal pill and the progestogen only pill. Your doctor will be able to advise you on which type of pill is suitable for you after looking at your medical history, lifestyle and general health.
- The combined hormonal pill
‘The contraceptive pill or birth control pill, popularly known as “the pill”, contains the female hormones oestrogen and progestogen,’ explains Dr Venkat. ‘They act by inhibiting ovulation and also alter the consistency of cervical mucus, preventing the free movement of sperm into the uterus. The hormones in the pill also makes the lining of the womb rather thin, to interfere with implantation of an embryo.’
- The progestogen-only pill
‘The minipill contains only progestogen and mainly acts by making the cervical mucus thick, to inhibit movement of sperm through the cervix; these pills also act on the lining of the womb.’
It’s important to remember that the pill’s role is to prevent pregnancy only. ‘The pill does not protect against sexually transmitted diseases,’ reminds Dr Venkat, ‘and therefore you should use other forms of contraception depending on your circumstances.’
How effective is the pill?
When taken properly (perfect use), less than one woman in every 100 will get pregnant while taking the pill. ‘There are going to be potential problems with any form of contraception, but when taken exactly as advised, the pill is more than 99 per cent effective,’ says Dr Venkat.
When taken properly, less than one woman in every 100 will get pregnant while taking the pill.
However, based on “typical use” – that is, taking into account the fact that you might forget to take a pill, or you might be sick, causing the pill to be less effective, it is 91 per cent effective, meaning that around nine women in every 100 will fall pregnant while taking the pill.
‘As we have said, the pill is extremely effective in preventing pregnancy, but when a woman does fall pregnant it tends to be because they haven’t taken it exactly as advised or “perfectly”,’ says Dr Venkat.
‘We know that day-to-day life can be hectic and it is easy to forget to take a pill. If this happens on a regular basis, it might be best to consider looking at other options, such as the contraceptive implant.’
Why might the pill fail to work?
Simply put: if you miss a pill, then it may not work. ‘You also need to check with your GP or family planning nurse whether any other medications you are taking will negatively interact with the pill,’ says Dr Venkat. This includes prescription medication, such as antibiotics, as well as non-prescription drugs and herbal remedies.
If you suffer from sickness or diarrhoea, the pill may also let you down when it comes to stopping a pregnancy.
‘If you suffer from sickness or diarrhoea, the pill may also let you down when it comes to stopping a pregnancy. In these cases, extra protection is suggested to prevent pregnancy.
‘It is also worth noting that if you take your first pill as advised, on the first day of your period, additional contraception isn’t needed. However, if you start at a later stage during your menstrual cycle, you will need to use a condom or another barrier method for at least seven days.’
Will a pregnancy test work if you are taking the pill?
If you are worried that you might be pregnant while you are on the pill, it’s best to do a pregnancy test. A pregnancy test will work even though you are taking the pill, because it measures levels of a different pregnancy hormone to the ones that are altered by the pill.
The pill contains the hormones oestrogen and progesterone, but a pregnancy test measures the level of the hormone human chorionic gonadotrophin (HCG), meaning it will still work, even if you are taking the pill.
If you get pregnant on the pill, will it affect the baby?
‘If you do get pregnant while taking the pill, there generally aren’t any negative implications,’ reassures Dr Venkat. ‘We advise that you speak to your GP if you have any concerns, but be assured that there’s little risk.’
How can you ensure the pill works?
‘The best thing you can do to ensure taking the pill works for you, is to take it at the same time every day,’ says Dr Venkat. ‘If you miss one, use additional protection until your pill is effective again, and the same if you have a tummy bug or are taking antibiotics.’