Pregnant while on birth control: Risks to pregnancy and odds of conceiving

Dangers Of Pregnancy On The Pill

So you’ve heard the stories where women using birth control get pregnant and you swear it’s just fiction. Think again! It can happen to you, too! Whether it is due to taking medications that reduce the effectiveness of your birth control, or a simple case of user error, there are times where the method of choice simply fails. Find out the odds of getting pregnant on different birth control methods, as well as how taking care birth control while unknowingly pregnant can affect your growing baby.

First off, it’s important to note that not all birth control is the same.

How birth control works

Birth control that contains synthetic progestogens such as the birth control pill, injectable Depo-Provera, vaginal NuvaRing, the patch, and hormonal IUDs do the following:

Suppress ovulation
Thicken cervical mucus to inhibit the sperm from reaching the egg
Makes the lining of the womb incapable for implantation should fertilization occur

The progesterone-only pill, common for breastfeeding mothers, works with the body to do the same. The non-hormonal IUD, however, uses copper, which has a spermicidal effect, as do sponges and condoms that contain spermicide. So, which one offers the least possibility of accidental pregnancy?

What are the odds of conceiving on birth control?
Here are the published percentages of effectiveness of the most common forms of birth control:

Birth control pill: 99.9% effective when taken correctly
Depo-Provera: 99.7% effectiveness when used correctly
NuvaRing: 99.7% effective with perfect use, and 92% effective with typical use
The patch: 99% effective in women weighing 197 pounds or less, and 92% effective in women over this marker
Progesterone-only pill (POP or “minipill”): 95% effective with perfect usage
IUD – non-hormonal : 99.5% effectiveness for 10 years
IUD – hormonal: 99+% effectiveness for 5 years
Condoms: 98% effective when used correctly
Spermicide: When used correctly, it is 85% effective; however, typical use brings it down to 71% effectiveness

Each method relies on correct usage for maximum pregnancy-preventing results. With that said, it’s the women on the other side of the percentages that are wondering how using birth control may affect their baby-to-be.

Risks of taking birth control while pregnant

If you become pregnant while using birth control, you may be concerned about the affect your prevention method may have had on your fetus before you knew you were pregnant.

Generally speaking, as long as you stop using birth control as soon as you find out you’re preggers, in most cases, your fetus may not be affected:

Birth Control Pill: According to MayoClinic.com, “…There's very little evidence that exposure to the hormones in birth control pills causes birth defects. Still, the birth control pill is a potent estrogen, [and] such exposure should be minimized.”
NuvaRing: According to Dr. Burt Webb of Scottsdale Center for Women's Health, "Neither birth control or NuvaRing causes a problem or increases the risk to the fetus."
IUD: According to PlannedParenthood.org, “If you are pregnant with an IUD in place, there is an increased risk of ectopic pregnancy, dangerous pelvic infection, miscarriage, [and] early labor and delivery.”
Depo-Provera: According to Pfizer.com, “[Although] there have been reports of an increased risk of low birth weight and neonatal infant death or other health problems in infants conceived close to the time of injection, such pregnancies are uncommon.”
Spermicide: As reported by Pregnancyandbaby.com, spermicide is not known to harm a growing fetus.

When pregnancy signs are mistaken as side effects

If you are unsure of whether your birth control of choice has stood by your side or has weakened in the heat of the moment, you may want to be familiar with the common signs of pregnancy, such as:

A missed period
Breast tenderness
Nausea
Exhaustion
Cravings or aversions to certain foods
Fetal movement

Be aware, however, that some of the signs of pregnancy can be dismissed as side effects of birth control. The best way to know whether or not you have joined the baby-on-board club is to take a pregnancy test.

If you are concerned about the risk of pregnancy while using your favorite choice in birth control, talk to your doctor about the best option for your lifestyle. If you should become pregnant, stop using your birth control immediately and contact your physician. Overall, you can have peace of mind knowing that when used correctly, it’s likely that the percentages are in your favor when it comes to birth control effectiveness!