A: The “best” method of birth control is one that is reliable, has a good safety profile and has minimal side effects.

Reliability. A reliable birth control is one that has a low failure rate and will be used consistently. The contraceptive pill is a popular method and effective at preventing pregnancy if you take the pill at the same time every day. By the same token, condoms and other barrier methods of contraception are good birth control methods if you use them every time. Some studies have suggested that the diaphragm is less successful for couples who already have children, perhaps because they’re less motivated to use this method with rigor.

Safety. Your breast milk is sensitive to the foods you eat and the medications you take. Hormonal birth control, in the form of pills, patches or injections, will all cause hormones to enter your breast milk. Some women feel more comfortable avoiding these methods because they prefer not to expose their newborns to any level of synthetic hormones. Combination hormonal methods such as the oral contraceptive pill include estrogen and progesterone. These methods may reduce the quantity of hormones that enter breast milk. Single hormone methods, such as the progesterone-only pill (also called the mini-pill), have not been shown to inhibit breast milk production and can be started soon after delivery. Condoms, of course, don’t interfere with breastfeeding and have the added benefit of preventing pelvic infections.

Side Effects. There is no perfect method of birth control; every method has its own side effects. The pill may cause mood swings, weight change and other hormonal effects. Spermicides may cause vaginal irritation. Condoms are usually well tolerated by women but may be less appealing to men. Also, lactation is associated with vaginal dryness and using a water-based lubricant can help increase comfort with condom use. The IUD may cause increased menstrual bleeding and cramping in some women. (Mirena®, a newer IUD containing progesterone, reduces menstrual flow and is effective for five years.)

Long-term plans. If you have completed your family, it makes sense to consider a long-term method of birth control such as the IUD or a sterilization procedure. Both of these will not interfere with breastfeeding and are extremely good at preventing pregnancy.

Talk to your doctor and your husband about your options. If you are exclusively breastfeeding (which means you don’t provide your baby with supplemental formula or other liquids), you are likely to be protected from a new pregnancy for the first three months. After that point, it is possible to get pregnant, even if you have not yet experienced a postpartum menstrual period. Most women decide upon a birth control method at their postpartum visit, usually around six weeks after the delivery.