Fertility Awareness Method
Pluses: Women who prefer not to use hormonal or mechanical contraception can use this method.
What You Should Know: Because the female body's indicators of fertility -- cervical mucus changes and basal body temperature -- are not reliable in the first two to three months after delivery, it can be difficult to learn and use this method. Cervical mucus doesn't return to normal until ovulation resumes, and basal body temperature can't be accurately measured unless a woman has had six hours of uninterrupted sleep, a rarity for most mothers in the first months of their baby's life.
Until regular cycles return, couples should use another method of contraception or -- if religious beliefs forbid other means -- withdrawal. According to Contraceptive Technology, withdrawal is 81% effective.
If you do decide to use a fertility awareness method (there are several), make sure you receive complete training in it to be certain you're doing it correctly.
Lactational Amenorrhea Method
Pluses: Some women who are nursing their infants have the choice of using this form of birth control. Proven effective in studies worldwide, the lactational amenorrhea method (LAM) has been endorsed by the World Health Organization and Georgetown University's Institute for Reproductive Health, among others.
Effectiveness: 98%, if you meet the criteria and perform it perfectly.
What You Should Know: LAM is very simple, but you should only consider using it if you fit all of the following criteria:
1. You've had no periods since the delivery.
2. All or most of the baby's nutrition is coming from your breast milk (meaning you nurse on demand at least every 4 hours during the day, and every 6 hours at night).
3. Your baby is younger than 6 months old.
"When any one of these conditions changes, a woman should use another family-planning method," says Kristin Cooney, a reproductive health expert at the U.S. Agency for International Development.
LAM works because the stimulation of the infant's suckling sends a signal to the mother's hypothalamus gland, which responds by decreasing the secretion of the pituitary hormones needed for ovulation. Once menstruation resumes, another contraceptive method must be used.