Quality family planning services are an important means of increasing knowledge about contraception and acceptance of effective methods, as well as influencing method choice. 1 In the 1970s, low contraceptive prevalence and poorly functioning health systems existed in many developing countries; in such settings, vertical delivery systems and community-based health workers were essential to the rapid increase of contraceptive knowledge and prevalence. Over time, however, the mode of family planning service delivery has evolved. Today, many family planning programs have been integrated into formal health delivery structures for a number of reasons. These include the success of earlier programs in sustaining contraceptive demand, the relatively high cost of community-based delivery, declining budgets for family planning and the need to increase efficiency in supervision and management. [2][3][4] A review of trials on integrated service delivery, however, found no consistent benefit of integration on patient outcomes, costs or health system performance in less developed settings, although the number of studies was small and their designs limited comparisons. 4 Nonetheless, two of the trials demonstrated that integration of family planning service delivery results in increased contraceptive use or uptake. 5,6 Because the demand for contraception fluctuates over the course of a woman's reproductive life, the timing of service delivery must be considered as part of any integration effort. The postpartum period is particularly important because appropriate birthspacing can improve maternal and infant health. 7 Moreover, the demand for effective contraception may be high immediately after delivery. Previous cross-sectional studies report positive associations between maternal and child health service use [8][9][10] and subsequent contraceptive use. In addition, prenatal services offer the opportunity to reach women who would be the primary target of family planning services. Because of this, global strategies have used prenatal care as an entry point in the delivery of core reproductive health services, including family planning. 11 The site of the present study is Mexico, a middle-income country of 106 million people, more than three-quarters of whom reside in urban areas. 12 During the 1980s, the Mexican government established community-based distribution programs to help reduce population growth rates through the rapid introduction of modern contraceptives. 13 These programs were integral to a doubling of the contraceptive prevalence rate from 30% in 1976 to 60% in 2005. 14,15 Although community-based health workers were essential to delivering family planning services to remote and rural populations in the 1970s, their role has diminished with urbanization and increased access to primary health facilities. Taking an integrated approach to service delivery, the Ministry of Health has incorporated family planning counseling into the national clinical guidelines for prenatal care. 16 The relationship between wome...