Taking Birth Control Pills While Pregnant & Their Side Effects

Taking Birth Control Pills While Pregnant & Their Side Effects

Human bodies are complex and taking into account the chance of human error, let us tell you something: oral contraceptives cannot offer a 100% guarantee against pregnancy. Thus, there are odds that a woman may get unexpectedly pregnant while taking birth control pills. Some experts believe that taking birth control while you get accidentally pregnant may not harm the growing foetus during early pregnancy, but it is vital to discontinue taking birth control immediately after learning about your pregnancy.

But what could happen if you accidentally continue taking birth control while pregnant is a common concern among women across the world, and you are not alone. To know, let’s dive a little deep into this topic, understand the possible outcomes, and get answers to common questions about taking birth control while pregnant.

How Does Birth Control Work?

With medical advancements today, there are several birth control methods – hormonal birth control like oral birth control pills, barrier birth control like condoms, surgical procedures like vasectomy and tying tubes, and long-acting reversible contraceptives (LARC) like IUD. Out of these, the most commonly used birth control method is oral pills. 

Oral contraceptives commonly have hormones similar to those produced by a woman’s body. Oral pills like minipill (progestin-only pill) prevent pregnancy by thickening the cervical excretion, which prevents the sperm from reaching the egg and also by suppressing the ovaries, which prohibits them from functioning at full strength. In simple terms, when you use birth control pills, your ovaries do not release the egg, and the cervical mucus thickens. This makes it difficult for a fertilised egg to implant in the uterus lining.

It is to be noted that these pills are 99 per cent effective when taken correctly. And, since it is easy to lose track of doses and timings to take the pills, the pills are left with only 91-93 per cent effectiveness with typical use.

For those who cannot work well with pills, implants or intrauterine devices (IUDs) are usually suggested.

What Happens If You Accidentally Take Birth Control Pills While Pregnant?

Accidentally Taking Birth Control Pills While Pregnant?

Most women may ask whether taking birth control pills affect a pregnancy. Studies indicate that taking birth control during the first few weeks of pregnancy may not adversely affect the developing foetus. However, there are some queries most women have regarding taking birth control pills while pregnant:

1. Are There Chances of Birth Defects?

Many women who suddenly become pregnant while taking birth control may be worried about their baby being born with some birth defects. But no concrete scientific evidence shows that taking birth control in the form of progestin-only or combination birth control pills while in your early pregnancy leads to increased chances of birth defects in babies.

2. Is There a Risk of Miscarriage?

Can taking birth control pills while pregnant cause a miscarriage? That may be another likely concern of women who experience an unplanned pregnancy in such cases. But again, there is no statistical data available that can establish a relation between the two aspects. After the fertilised egg implants itself, birth control pills can have relatively no effect on it – since the hormones present in the pill are meant to thicken the cervical mucus to prohibit sperm from entering the uterus and stopping ovulation, none of these things occurs when implantation has already happened.

Another myth regarding birth control pills and pregnancy is that taking an emergency contraceptive pill can cause an immediate miscarriage. That, again, is not true. These pills do not have any effect on the body once implantation has occurred.

3. Is There a Possibility of an Ectopic Pregnancy?

Evidence suggests that taking a progestin-only birth control pill (minipill) while pregnant may increase the prospects of the occurrence of an ectopic pregnancy (where the fertilised egg grows outside the uterus) in some cases.

4. Is There a Risk of Preterm Delivery and Low Birth Weight?

Although debatable, women who conceive while on the birth control pill may be at a greater risk of experiencing preterm labour, low birth weight, and a few congenital urinary tract anomalies.

Please Note: It is essential to understand here that research done in this field is not extensive, as it may be against medical ethics to expose a mother and her unborn child to any potential danger. Thus, much of the data has been collected from epidemiological research relating to mothers who took birth control pills during their early pregnancy in contrast to those who didn’t.

Risk of Continuing Birth Control While Pregnant

Now that you have got a big fat positive on your pregnancy test, there’s no reason to continue them. Besides, there is not much scientific evidence suggesting harm to the pregnancy if you accidentally continue taking hormonal birth control during pregnancy. However, your doctor will recommend you stop taking them as their purpose is gone.

While older studies suggested that taking contraceptives that contain the hormone progestin during early pregnancy could lead to hypospadias (a congenital malformation in which the urethral opening is on the ventral side of the penis), recent studies point out otherwise. In a recent study, it was found that exposure to oral contraceptives just before or during pregnancy does not appear to be associated with an increased risk of major birth defects. Another 2016 study concluded that maternal exposure to oral contraceptives has a role in the development of wheezing, asthma and rhinitis in children. Any extended use of OCP is more likely to increase the risk of wheezing and rhinitis.

Hence, hormonal birth control won’t risk pregnancy or abort it once you are pregnant. 


1. Can I Use Birth Control Pill While Breastfeeding?

Please note that there is a possibility that combination birth control pills containing estrogen may cause a reduction in the breast milk supply and cause blood clots. Progestin-only birth control, on the other hand, is safe and is more likely to be recommended by health experts to take during breastfeeding. Therefore, it is safe to start with a mini pill (progestin-only oral pill) at any time during the breastfeeding phase. Taking minipill does not affect breast milk in any manner or its production. Therefore, you can start with minipill right after your delivery or even when you are not breastfeeding.

2. How Do I Know If I Am Pregnant While Taking Birth Control Pills?

Although missed periods are a common sign of pregnancy, it is debatable with the use of birth control pills. When using birth control, we often tend to lose track of our periods because they sometimes become less regular or go away completely. Hence, it is better to consider other pregnancy signs as well if you are planning to take a pregnancy test:

  • Nausea and vomiting
  • Breast tenderness
  • Extreme tiredness
  • Sudden and unusual food cravings or dislikes

If you experience any of the following symptoms and might have as well missed some pills, then it is best to get a pregnancy test at home or at a healthcare service.

Unexpected pregnancy while on birth control pills is not unusual. If you feel you may be pregnant, take a home pregnancy test to confirm it. In case you are pregnant, it is advisable to stop taking birth control pills at once. It is also wise to read the product labelling carefully before buying birth control pills to ascertain the potential risks in the incidence of pregnancy. In any case, irrespective of any probable risk factors, it is sensible to refer to a doctor for further guidance.


1. How effective is contraception at preventing pregnancy?; NHS; https://www.nhs.uk/conditions/contraception/how-effective-contraception/

2. Britton. LE, Alspaugh. A, Greene. MZ, McLemore. MR; CE: An Evidence-Based Update on Contraception; Am J Nurs.; PubMed Central; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7533104/#R9; February 2020

3. Effectiveness of Birth Control Methods; The American College of Obstetricians and Gynecologists; https://www.acog.org/womens-health/infographics/effectiveness-of-birth-control-methods

4. Carmichael. SL, Shaw. GM, Laurent. C, Croughan. MS, et al.; Maternal Progestin Intake and Risk of Hypospadias; Arch Pediatr Adolesc Med.; JAMA Pediatrics; https://jamanetwork.com/journals/jamapediatrics/fullarticle/486138; October 2005

5. Charlton. BM, Mølgaard-Nielsen. D, Svanström. H, et al.; Maternal use of oral contraceptives and risk of birth defects in Denmark: prospective, nationwide cohort study; BMJ; https://www.bmj.com/content/352/bmj.h6712; January 2016

6. Yamamoto-Hanada. K, Futamura. M, Yang. L, Shoda. T, et al.; Preconceptional exposure to oral contraceptive pills and the risk of wheeze, asthma and rhinitis in children; Allergol Int.; https://pubmed.ncbi.nlm.nih.gov/27038776/; July 2016

7. Facts about Hypospadias; CDC; https://www.cdc.gov/ncbddd/birthdefects/hypospadias.html#ref

8. Birth Control; U.S. Food & Drug Administration; https://www.fda.gov/consumers/free-publications-women/birth-control

9. Birth control pill FAQ: Benefits, risks and choices; Mayo Clinic; https://www.mayoclinic.org/healthy-lifestyle/birth-control/in-depth/birth-control-pill/art-20045136

10. Minipill (progestin-only birth control pill); Mayo Clinic; https://www.mayoclinic.org/tests-procedures/minipill/about/pac-20388306

Also Read:

Side Effects of Birth Control Pills
Use of Sleeping Pills during Pregnancy
What Medicines to Avoid in Pregnancy

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