Objective: To determine the efficacy of the lactational amenorrhea met
hod of family planning (amenorrhea during full or nearly full breastfe
eding for 6 months postpartum). Design: Prospective noncomparative stu
dy. Setting: Normal breastfeeding women in Karachi and Multan, Pakista
n, most delivered at home by a midwife. Patients: Three hundred ninety
-nine newly delivered mothers who successfully had breastfed a previou
s child and chose the lactational amenorrhea method to prevent a subse
quent pregnancy, 391 of whom were followed for a full year. Interventi
ons: Mothers were taught, before or shortly after delivery, to use the
method and were interviewed in their homes each month by a Lady Healt
h Visitor. Main Outcome Measure: Life-table pregnancy rates. Periods o
f postpartum or lactational abstinence were excluded in the calculatio
n of the pregnancy rates. Results: During full or nearly full breastfe
eding, while the women were amenorrheic and not otherwise contraceptin
g, the rate of pregnancy was 0.6%. The pregnancy rate during lactation
al amenorrhea alone was 1.1% at 1 year postpartum.Conclusion: The lact
ational amenorrhea method was found to be highly effective for 6 month
s. A high degree of contraceptive protection endures for a full year d
uring lactational amenorrhea, but not after the return of menses durin
g breastfeeding.