Millennium Development Goal 5: Improve maternal health
Target: Achieve, by 2015, universal access to reproductive health
Much ill health among pregnant women is preventable, detectable or treatable through antenatal visits. Antenatal care provides an opportunity to reach pregnant women with multiple interventions that could be vital to their well-being and that of their babies. The minimum number of antenatal care visits during pregnancy recommended by UNICEF and WHO is four.
In the developing world as a whole, three quarters of pregnant women receive antenatal care from a skilled health provider at least once. But in the least developed countries, 1 in 3 women do not receive any antenatal care during pregnancy, and 3 in 5 women deliver their babies without the assistance of a skilled health worker.

Source: Demographic and Health Surveys, Multiple Indicator Cluster Surveys and other national household surveys
Reference: http://www.unicef.org/sowc09/docs/SOWC09-FullReport-EN.pdf