Vietnam has high numbers of maternal and infant mortality and morbidity. Each year, 1,500 women die and 45,000 others become disabled as a result of pregnancy and childbirth complications. 1 There were 37,700 neonatal deaths in Vietnam in 1999. 2 The maternal mortality rate is 165 per 100,000 live births 3 and the infant mortality rate is around 30 per 1,000 live births. 4,5 Antenatal care (ANC) has been proven to be effective in preventing pregnancy adverse outcomes. 6 For ANC to be effective, women should have enough visits at appropriate times, with sufficient ANC content. The World Health Organization (WHO) recommends four visits at the 4th, 6th or 7th, 8th, and 9th month for women in developing countries. 7 The Vietnamese government recommends three visits, one during each trimester. 8 WHO recommends three basic components of ANC content: (1) biomedical assessment based on medical history, physical examination, and laboratory tests; (2) health promotion; and (3) care provision. 7 To measure ANC adequacy, many indicators and indices have been developed in the world. Single indicators are any ANC, number of ANC visits, and duration of pregnancy at entry to ANC. Complex indices that combine number of ANC visits and duration of pregnancy at first visit are the Kessner index, 9 the Graduated Index of Prenatal Care Utilization, 10 the Adequacy of Prenatal Care Utilization Index, 11 and the Prenatal Care Evidence-Based Index. 12 These indices are suitable for developed countries because of the high cutoff points. There has been a modified index in the Philippines with the lower cutoff point of five visits and initial visit within the first three months, 13 but this index might not be suitable for other less developed countries like Vietnam. Editor's note: This paper by Drs. Trinh, Dibley, and Byles shows with clarity the benefit of antenatal care and improved outcomes in maternal and infant morbidity and mortality. The data set used, which goes up to 1999, also suggests an improving trend in infant mortality as the economy grows and the GDP increases. These rates of improvement are at a rate of about 7% annually. In fact, infant mortality rates have changed dramatically in the last two decades in Vietnam.