Medically reviewed by Sophia Yen, MD, MPH – Written by Pandia Health Editorial Team

The average woman in the U.S. wants to have two children. To accomplish this goal, she spends only about 3 years of her life: pregnant, in the postpartum period, or attempting to conceive. However that the average woman will spend almost 30 years of her life trying to avoid pregnancy, and that’s if she even wants any children in the first place.

There is no such thing as 100% effective birth control. For example, it’s even possible to get pregnant after surgical sterilization (vasectomy or tubal ligation) though very rare. But using effective forms of birth control significantly reduces a woman’s chances of getting pregnant. For women who are not postmenopausal and who want to avoid pregnancy, they will need to understand the effectiveness rates of different forms of birth control and if using birth control while pregnant can impact the pregnancy.

What is the difference between “perfect use” and “typical use” of birth control?

When people talk about birth control effectiveness rates, it’s critical to understand that there are 2 different rates: perfect use vs typical use. Typical birth control usage rates include human error and are often calculated for the first year of using a new birth control method. Birth control methods that require fewer instances of human intervention tend to be the most effective.

For example, the birth control pill is 99% effective when taken correctly, but what human being is perfect? The typical use of birth control affects the rate of failure such as forgetting a pill. For the most part, the pill is more like 91% effective “typical use” effective rate. Women can forget to take a pill, take a pill very late, or vomit after taking a pill (from illness, alcohol intoxication, etc). All of these factors and more can influence the effectiveness rate of the pill. When evaluating a birth control method, it’s important to look at the typical use rate of a given method before switching birth control.

What is the perfect use versus typical use rates of some of the most popular birth control methods?

  • IUDs: 99% effective regardless.
  • The birth control pill, patch, or ring: 99.7% vs. 91% effective.
  • Male condoms: 98% vs. 82%.
  • The birth control implant: 99% effective regardless.
  • The ovulation method aka Natural Family Planning: 97% vs. 78%.
  • Withdrawal: 96% vs 78%

How many women become pregnant as a result of birth control failure?

If 100 women and their male partners were to use condoms perfectly every time they had intercourse during a year, only 2 of those women would experience birth control failure or unintended pregnancy. Likewise, only 1 woman out of 100 women using the birth control pill, patch, or ring in a given year would become pregnant after using the method perfectly. So, perfect use of some of the most popular birth control methods can still result in an unintended pregnancy.  That’s why at Pandia Health we always recommend using BOTH a hormonal method and condoms. Using 2 methods, you theoretically decrease the risk to 1/100 *2/100 = 2/10,000 and the condoms protect against sexually transmitted infections like HIV, Chlamydia, HPV, Gonorrhea, and more.

What is the definition of unintended pregnancy?

There are two ways to define an unintended or unplanned pregnancy:

  • A woman became pregnant before she wanted or was ready to conceive.
  • A woman became pregnant but does not want to have a baby at any time in her life.

These types of pregnancies are also referred to as “unplanned” pregnancies. Any other time a woman conceives, those pregnancies are referred to as “intended” pregnancies. Intended pregnancies also include pregnancies that were wanted sooner than they occurred. It’s also critical to understand that women who have an “intended” pregnancy may not have necessarily planned to become pregnant.

  • In 2011,  in the U.S., 45 out of every 1000 pregnancies were unintended.
  • About 5% of all reproductive-age women in the U.S. each year experience an unintended pregnancy.  (That’s 1 in 20 women.)
  • Unintended pregnancy rates in the U.S. are highest among low-income women and minorities. (This is most likely due to lack of access to birth control.)
  • Unintended pregnancy rates decrease with age. Women between the ages of 15 and 19 experience the highest rates of unwanted pregnancy.
  • About 42% of unintended pregnancies (excluding miscarriages) end in abortion and 58% end in a live birth.

Since 2008, in the US, the unintended pregnancy rate and abortion rate for women across all age groups, racial, and socio-economic lines decreased. Studies indicate that greater access to birth control and greater access to more effective birth control methods (specifically LARCs [Long Acting Reversible Contraceptives]) has led to a decrease in unintended pregnancy across the board.

Can taking hormonal birth control pills, using the contraceptive patch, or using the contraceptive ring affect a developing embryo if a woman becomes unintentionally pregnant?

Research has found that the hormones present in the birth control pill do not adversely affect the developing embryo.

How soon can a woman conceive if she stops taking the birth control pill?

Most women conceive within a few months after stopping hormonal birth control. It can take the body a few cycles to adapt to the loss of steady hormones and ovulate. However, there is always a chance that a woman can become pregnant immediately after stopping hormonal birth control.

Of note, women with PCOS are most fertile when they come off the birth control pill, patch, or ring because that is when their hormones are the most normal. The longer they are off the birth control pill, patch, or ring, the more abnormal their hormones become (they go back to the abnormal PCOS levels).

Which birth control methods the most effective for avoiding unintended pregnancy?

The birth control shot, ring, patch, and pill are about 99% effective with perfect use. However, these types of birth control methods require human intervention. A patch can fall off, a pill or ring can be forgotten, or a woman cannot get in to see a provider for a birth control shot within the intended time frame.

Birth control methods that are long-lasting, and that do not require as much human intervention are some of the most effective methods for avoiding unintended pregnancy. The birth control implant is 99% effective, and once it is placed, it can last for 3 years. IUDs are also 99% effective and can last for up to 7 years for IUDs with hormones (Liletta® or Mirena®) or 12 years (copper IUD) per the World Health Organization. The biggest issue facing IUD users is if they can find a provider to place the IUD.

However, these long-lasting devices may not be the best birth control choice for some women. They may not want birth control that lasts for so long (though you can have it removed at any time and resume fertility within the month) or they may not be comfortable having a device in their body. The birth control ring, patch and pill are still highly effective even typical use,  and there are so many different types of pills (about 40) that you and your provide should be able to find one that meet’s your unique needs.

If you’re looking for affordable, safe, and effective hormonal birth control, please contact Pandia Health today. Representatives are  happy to assist you with any questions you may have about having birth control pills, patches, or rings delivered straight to your home.