Pregnancy Risk With the Mini-Pill and Breastfeeding

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Both breastfeeding and birth control pills will reduce your risk of pregnancy, but there are factors that affect their effectiveness. As a new mother, you may have begun taking the mini-pill while you are breastfeeding. Learn about your pregnancy risk when using these two methods.

Mini-Pill Effectiveness

A progestin-only hormonal birth control pill is 91% effective with typical use and 99.7% effective with perfect use. It must be taken precisely as directed and at the same time each day. If you're not sticking with the plan exactly, then chances of a pregnancy increase.

Even if you miss just one pill, you'll need to use a backup method of birth control for 48 hours until you are back on track with the pills. If you made a mistake and then you don't have a period within 45 days, you could definitely be pregnant.

If you missed more than two pills, there is a chance you will have ovulated and you need to use a backup method for 2 weeks. You will need to rule out pregnancy after a couple of weeks.

In addition, if you're in a country besides the United States, the mini-pill you've been prescribed might be different. If you miss a pill, you might need to use a backup method for up to 2 weeks. Be sure to contact your healthcare provider or read the package insert to be sure.

Breastfeeding and Pregnancy Risk

Breastfeeding can reduce your fertility, but should you consider that a backup birth control method? Perhaps, if you meet the following criteria:

  • Exclusive breastfeeding: Your baby is fed only breast milk, on-demand, without supplements, solids, or pacifiers. You must nurse at least every 4 hours during the day and every 6 hours at night.
  • Infant age: Your baby is 6 months old or younger.
  • Menstrual cycle: Your period hasn't returned.

Breastfeeding can be used as a lactational amenorrhea method (LAM) as it can prevent ovulation. When done perfectly, it is about 98% effective. But If you began using the mini-pill because your period returned, then breastfeeding cannot be considered to be a backup birth control method. Having your period means you have ovulated and are at risk for pregnancy.

If you have returned to work and are pumping milk to be given at childcare, that is not the same as feeding your baby on demand. While it doesn't provide natural birth control protection, pumping is still beneficial for both you and your baby.

Pregnancy Signs vs. Mini-Pill Side Effects

The known side effects of the mini-pill are also symptoms of pregnancy (such as dizziness, nausea, changes in your breasts, weight, mood, sex drive, and menstrual flow).

Before you dismiss any of your symptoms as side effects from your birth control, it's wise to take a home pregnancy test. But if it's negative, know that it's possible to get a negative result and still be pregnant. You may want to visit your doctor to rule out pregnancy with certainty.

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Article Sources
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  1. Cleveland Clinic. Minipill. Updated January 28, 2018.

  2. MedlinePlus U.S. National Library of Medicine. Progestin-Only Oral Contraceptives. Updated January 15, 2016.

  3. Planned Parenthood. Breastfeeding.

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