Ethics
In the primary study, the field workers explained the study purpose and participant requirements before obtaining written informed consent from participants during the interview process. Participants were made aware that their participation in the study was entirely voluntary and informed of their right to withdraw their consent before, during or at the end of the interview without consequences. Participants were also given the opportunity to read through the questionnaire and ask questions prior to the interviews. This study is based on data derived from interviews conducted in the primary study. Ethical approval for the primary study was granted by the Faculty of Health Sciences Research Ethics Committees of the Universities of Pretoria (121/2005) and Cape Town (381/2005).
Dependent variables
We examined two dependent variables (a) timing of ANC (early versus late ANC initiation) and (b) frequency of ANC attendance (adequate versus inadequate ANC attendance) during last pregnancy.
Early initiation (as recommended in literature guidelines) [2, 4] was defined as a first ANC visit at or earlier than 16 weeks during the last pregnancy. The original questionnaire included questions on antenatal care relating to the women’s pregnancy with their last born child. The women were asked their gestational age when they first initiated antenatal care during that (their last) pregnancy. They were asked to report on the number of months pregnant at the time of their first ANC visit, which was easier for the women to recall, and then converted to weeks for analysis. The responses were then coded as either early ANC initiation (1) for those who attended at or before 16 weeks gestational age or late ANC initiation (0) for those who attended after 16 weeks gestational age.
Adequate number of ANC visits was defined as at least four visits during the last pregnancy. This latter criterion follows recommendations by the WHO in the focused ANC model for low resource countries and the recommendations of the basic antenatal care (BANC) approach [5]. Even though the 2007 national Guidelines for Maternity Care in South Africa are not consistent with the WHO guidline (recommend four follow-up visits after the first ANC visit scheduled for 20, 26, 32, and 38 weeks, and 41 if still pregnant for uncomplicated pregnancies – i.e. total 5 or 6 visits), this study used 4 visits as the cut-off for adequate attendance.
Participants responded to the question, “How many times did you go for antenatal appointments during this pregnancy?” The responses were then coded as either Adequate ANC attendance(1) for those who attended at least 4 ANC visits during the pregnancy or Inadequate ANC attendance (0) for those who attended less than 4 ANC visits during the previous pregnancy.