Can you get pregnant on the pill?
The birth control pill is a popular and effective method of contraception. However, some factors such as missing a pill, vomiting and being on certain medications can reduce the effectiveness of the pill and may result in an unwanted pregnancy.
How effective is the pill?
The combined pill contains hormones that prevent ovulation which is when the ovaries release an egg ready for fertilisation. The minipill, often used whilst a woman is breastfeeding, causes the cervical mucous to thicken and the uterine lining to thin which limits the sperm from reaching an egg.
Reasons for the contraceptive pill to fail
- Missing a day: If a woman misses taking her pill for a day, her hormone levels are affected and may not remain at a consistent enough level to prevent ovulation and a possible pregnancy.
- Not taking the pill at the same time each day: a woman should take her pill at around the same time each day in order to keep her hormone levels at a consistent level. The minipill only allows a three-hour time window. If a woman misses that window, she should use a backup birth control method for the following two weeks such as condoms.
- Vomiting: If you become unwell and vomit not long after taking the pill, it may not be fully absorbed into your system. If you experience vomiting, wait a short while then take another pill.
- Not starting a new packet when the previous pack is completed: It is essential to start your new packet of pills as soon as you complete the previous pack. Missing a few days between packs can make the pill less effective at preventing pregnancy. If a woman misses two or more pills in a row, she should use back-up contraception or avoid intercourse until she has taken the pill for 14 consecutive days.
- Medications: Some medications can make the pill less effective. It is always wise to check with your doctor before commencing any new medication whilst on the pill. Medications can include certain antibiotics and antifungal drugs. Other more long-term medications and supplements that may affect the effectiveness of the pill include some drugs treating epilepsy, anti-viral medications used to treat HIV and a herbal remedy such as St John’s Wort.
Birth control pills are very effective if taken correctly and not missed. If you are concerned about remembering to take the pill as recommended then you should speak to Dr Kliman about other birth control options. There are other options available that do not require taking a pill every day such as an IUD or an progesterone releasing rod.
Tips for preventing pill failure
- Take the pill at the same time each day
- Use an app that tracks periods and provides pill reminders
- Read the packaging and follow instructions given to you by your doctor
- Always ensure you have a new packet ready at least a week before your current pack ends
- Always take a missed pill as soon as possible
- Use a backup method of contraception such as condoms if you have missed two or more pills in a row