We explore trends in first-union formation in Bulgaria from 1960, using data from the national Gender andGenerations Survey of 2004. We analyse jointly the transition into cohabitation and directly into marriage.The standardized marriage rate falls dramatically from the early 1980s; the corresponding rate of entry intocohabitation has already increased from the early 1960s but (surprisingly) falls moderately toward the endof our period. Cohabitation also tends to last progressively longer in more recent periods. The analysisshows that a pregnancy leads to a dramatic increase in the rate of both kinds of union formation: theincrease is by a factor of almost 20 for marriage formation and about 10 for entry into cohabitation, ceterisparibus. Our findings suggest that, in Bulgaria at least, some manifestations of the Second DemographicTransition can be detected as early as the 1980s.