Initiation of contraception postpartum.
In this case-control study, we compared 97 cases who became pregnant within one year postpartum and underwent an induced abortion to 97 non-pregnant controls who were postpartum for a similar time interval. Two percent of cases conceived when fully breastfeeding and amenorrhoeic. A logistic model was used to identify risk factors for an unwanted pregnancy early postpartum. The most important risk factors were: time since menses resumption, number of menstrual bleedings, contraception, parity and education. The strong protective effect of breastfeeding and amenorrhoea was evident in the first 24 weeks postpartum, from 25-32 weeks the effect of amenorrhoea persisted, and after 32 weeks neither variable had any effect. The main risk factor for the outcome pregnant/non-pregnant in the first and the second interval was time since menses resumption; time since weaning works as a distal causal factor. After 32 weeks postpartum, the effect of contraceptive use and parity became important. The results of this case-control study suggest that the lactational amenorrhoea method, a recently proposed method of family planning, can be used up to 32 weeks postpartum for amenorrhoeic and fully or partially breastfeeding Slovenian women. Afterwards, women should be encouraged to use reliable contraceptives regardless of their breastfeeding and amenorrhoea status.