A vaginal ring (like NuvaRing) is a flexible ring that's inserted into the vaginal canal like a diaphragm, but unlike the diaphragm it stays in place for one month and releases a low dose of estrogen and progestin over a 21-day period. Thanks to the low dosage, NuvaRing causes fewer side effects than the pill. It's 98-percent effective when inserted properly.
Birth control patches (like OrthoEvra) are adhesive patches that can be placed on the abdomen, hip, or upper arm. You must replace the patch every week. This method works by delivering progestin and estrogen through the skin and into the bloodstream. It's a good option for women who can't remember to take the pill but not those who are nursing. It's 99-percent effective. Recent reports caution about a possible increase in the likelihood of blood clots with this method.
A progestin shot (for example, Depo-Provera) is a shot of synthetic progesterone administered in a doctor's office every three months. It doesn't affect breast milk quality, but having to go to a doctor's office every three months can be a burden to busy moms. This is equally effective for non-breastfeeding moms.
A cervical cap (Prentif Cervical cap is an example) is a thimble-shaped, rubber cap that acts as a barrier preventing sperm from entering the uterus. It's smaller than a diaphragm and can be kept in place for up to two days without additional applications of spermicide needed to maintain effectiveness. It's hormone-free, but its success rate is alarming: there's a one-year failure rate of 20 percent.
A diaphragm is a barrier method, usually a latex or silicon disk with a spring in the edge. It is inserted into and stays in the vagina and holds spermicide up to the cerivix. Sperm would have to swim through the spermicide to get to the egg. This one also has the advantage of no hormones, but the disadvantage of less than optimal effectiveness.
Condoms not only protect against pregnancy, but also sexually transmitted diseases. If used correctly, condoms are about 94- to 97-percent effective. On the other hand, the female condom is only 80- to 95-percent effective, but it can be inserted up to eight hours before intercourse. A good rule of thumb when using condoms is to also use a spermicide.