There are five general categories: conservative, barrier, hormonal, long term (IUD), and permanent. We'll also look at breastfeeding considerations and what to do if sex happens without any birth control on board (i.e. emergency contraception).

When assessing how effective a particular method is, doctors cite the overall chances of getting pregnant within one year. For example, birth control pills are about 93% effective. That means of 100 sexually-active couples on birth control pills, 93 won’t be pregnant at the end of the year. They fail to prevent pregnancy 7% of the time. 

We’ll talk about hormones again in this section, specifically estrogen and progesterone. However, the actual hormones used in birth control can be any number of synthetic estrogens or progesterones. I won’t bore you with the real names of the medications. Just know that when we say “estrogen” it can refer to various medications in the estrogen family of drugs, while “progesterone” can mean any number of commercially available progesterone-like medications.

None of the forms of birth control cause an abortion. That is, none of these methods end an established pregnancy. They all primarily work by preventing fertilization, the union of sperm and egg. The only exception is perhaps the copper IUD, which likely prevents fertilization, but it's not certain. 

In terms of popularity, The Pill is the most widely used method of reversible birth control, but IUD usage has been steadily increasing for years. Many couples use a variety of methods over the course of their marriage, depending on the season of life they’re in. In medicine, there’s always an aspect of trial-and-error to find a therapy that fits each person. Sometimes the only way to discover what works (or doesn’t work) is to give it a shot. 

It’s worth mentioning here that abstinence is the only sure-fire, 100% effective way to prevent pregnancy. Short of a miracle, if you don’t have sex, you won’t get pregnant. If you’re reading this, you’ve likely crossed abstinence off your list already, but it’s always worth considering. Apart from a hysterectomy, nothing else is as effective.

Whatever your goals for birth control, there’s a method that’s right for you and your spouse. As we said earlier, your choice should be well-understood, easy to use, and (most of all) keep your conscience clear.

All that being said, let’s begin with the simplest category: Conservative.

FOOTNOTES

(1) Fertilization can theoretically be bypassed. Also, implantation elsewhere in the body (outside the uterus) can very rarely produce a live birth. 

(2) Abdominal pregnancies occur when implantation occurs in the abdomen, away from the uterus, fallopian tubes, and ovaries. This is a very rare type of ectopic pregnancy. It’s extremely unlikely the baby will survive. 

All Scripture quotations are from The English Standard Bible (ESV). Crossway, 2001.