The Brazilian Total Fertility Rate (TFR) plummeted from 6.2 in 1960 to 2.3 in 1999. Despite the substantial decline, there has been an increase in union instability, which has been shown to increase the level of fertility in Brazil, and an increase of the relative contribution of teenage pregnancies to the overall level of fertility. We argue that Brazil represents a case of rapid fertility transition where the family planning program has had little influence and where, were it not for specific characteristics of teenagers and consensual unions, the TFR could reach even lower levels. We observe that in the absence of other methods, the fertility decline in Brazil is primarily due to the increased prevalence of female sterilisation. In this paper we desegregate the fertility indicators of different groups of women and the effect of these different measures on total fertility. We have found that the decline, powered by female sterilisation, would have been more rapid in the absence of the increase in teenage pregnancy and union instability.