Résumé
Bongaarts's model of Ci calculation was used to calculate the contribution of breast-feeding to family planning. This cross-sectional study was conducted in the area of Istanbul [TURKEY] Silivri Public Health Practice and Research Center between the dates of 20th May-1st October 2005. In this study whole under 1 year old babies, composed the sample [n=1247]. Bongaarts model can be summarized as Total Fertility Rate [TFR]= TF x Ci x CA x CC x Cm and takes its bases from TF [total fertility]. Ci is the Postparum infekunditi index. Ci= 20/[18.5+i] is calculated by this formula. The first menstruation period, after pregnancy ends, was taken as the value 'i'. The average age for the total 1247 mothers who contributed to this study was 26.7 +/- 5.2 [R: 16 - 50] yr. The women whose menstruation turned back [n=830], the average amenore period was found as 3.0 +/- 1.9 [1-12 months]. Ci's average value was 0.94 +/- 0.07 [0,66-1.03] and a r= -0.08, P= 0.012 correlation was appointed between mother's age and Ci. 7.7% of participants [n: 96] used breast-feeding as a contraceptive method. These participants used breast-feeding as contraception for 16.9 +/- 14.5 wk. Breast-feeding is a reliable and a positive affecting method of family planning for both improving the baby and mother's health. Furthermore also by affecting TFR over Ci, it provides a positive contribution to society health