Prolonged breastfeeding as a birth spacing method.
D001942:Breast Feeding; D003267:Contraception / Q000379:methods*; D003906:Developing Countries; D005193:Family Planning Services / Q000379:methods*; D005260:Female; D006801:Humans; D007774:Lactation; D008598:Menstruation; D010060:Ovulation; D011247:Pregnancy