Introduction: Consecutive pregnancies with an of interval less than two years is associated with adverse consequences for the mother and child. Education and support of women during breastfeeding is one of strategies that have been used for appropriate spacing between pregnancies. This study aimed to investigate the effect of peer support on the incidence of pregnancy during breastfeeding and the use of family planning methods in Ilam, Iran.
 
Materials & Methods: This interventional study was conducted in birth and health centers of Ilam between 2010 and 2012 among 240 nulliparous women who were randomly divided into case and control groups. The control group received the standard educational programs, while the case group received both the standard education and peer support from 30 consultants for six months after delivery. One hundred fifty-four participants (79 subjects in the case group and 74 in the control group) completed the questionnaires.. The collected data were analyzed using decriptive statistics such as mean and percentage and chi-square test and Fisher's exact test in SPSS, version 16.
 
Findings: The results showed that 24 months after delivery,  pregnancy rate during breastfeeding in the control group was significantly higher than the case group (20% v.s  1.5%; P=0.004). The time of pregnancy in the control group was significantly earlier than the case group(9.6±3.56 months postpartum vs. 18.26±1.25; p=0.01). The two groups were statistically different in terms of onset of use of contraceptive methods (72.71±61.35 vs. 10.02±36.71 days post-partum; P=0.001).
 
Discussion & Conclusions: Appropriate education and consultation programs for young and inexperienced women can prevent pregnancies during breastfeeding.