Lactational Amenorrhea Method (LAM) Calculator
Check whether breastfeeding can still protect you from pregnancy with the lactational amenorrhea method (LAM): the three WHO conditions, how many days of protection are left and when it ends.
How it works
LAM works only while ALL three are true: baby under 6 months AND no return of monthly bleeding AND fully or nearly fully breastfeeding · end date = birth date + 6 months
The lactational amenorrhea method uses the natural infertility that frequent breastfeeding causes after birth. The WHO Family Planning Handbook states it is more than 98% effective — about 2 pregnancies per 100 women in the first 6 months — but only while three conditions all hold: the baby is under 6 months old, monthly bleeding has not returned (bleeding in the first 8 weeks does not count) and the mother fully or nearly fully breastfeeds, often, day and night. As soon as one condition stops, fertility can return before the first period, so another method should start right away.
Worked example
Your baby was born on July 1, 2026 and you check on October 8, 2026: the baby is 14 weeks 1 day old, your bleeding has not returned and you breastfeed fully, so you are Protected by LAM (about 98% effective) until January 1, 2027 — 85 days of protection left.
Sources: WHO & Johns Hopkins CCP — Family Planning: A Global Handbook for Providers (2022), Lactational Amenorrhea Method · WHO Medical eligibility criteria for contraceptive use (2015)
Frequently asked questions
Can I get pregnant while breastfeeding?
Yes. Breastfeeding only protects reliably when all LAM conditions are met: baby under 6 months, no periods and full or nearly full breastfeeding day and night. Otherwise ovulation can return before your first period.
How effective is the lactational amenorrhea method?
With correct use about 98–99% effective in the first 6 months after birth — around 2 pregnancies per 100 women. It is less effective if feeds are spaced out, if the baby gets regular formula or solids, or if you are often separated from the baby.
What counts as “nearly full” breastfeeding?
Almost all of the baby’s feeds are at the breast, with only occasional sips of water or other drinks, and long gaps between feeds are avoided — WHO guidance suggests no more than about 4 hours by day and 6 hours at night.
Which contraceptive can I use while breastfeeding?
Copper or hormonal IUDs, implants, progestin-only pills or injections and condoms are all compatible with breastfeeding. Combined estrogen methods are usually delayed until at least 6 weeks after birth. Ask your health provider.
Related calculators
This calculator gives population averages for education only. It is not a method of contraception or a diagnosis — talk to your doctor, gynecologist or fertility specialist about your own situation.