In the study, 462 pregnant women enrolled for PMTCT Option B Plus will be followed up for 12 months in an open cohort. The sample size was calculated using Stata software based on a power of 0.8, a margin of error of 0.05, a design effect of 1.1 and a retention rate of 0.45. Six randomly selected eMTCT sites in Mashonaland East Province were chosen for the study. Retention rate at the sites since 2013 will be calculated. Three sites with lower retention will be considered as the exposure sites. The other 3 sites will be the unexposed sites. Option B Plus, a recently introduced and recommended PMTCT option, was meant to benefit pregnant women, in addition to their children and sexual partners. Hence, the involvement of women as participants. Four focus group discussions will also be done, with nursing mothers to ascertain the barriers and facilitators of retention in PMTCT Option B plus. Included in the study will be HIV positive pregnant and nursing women coming for PMTCT Option B Plus. Women who can communicate in English or Shona and are without psychiatric conditions will also be included. Emancipated minors, below 18 years of age will also be included. Excluded from the study will be women enrolled in PMTCT Options A or B, women with psychiatric conditions or those who are too ill to participate. The study was approved by The Medical Research Council of Zimbabwe. Signed voluntary consent is sought from participants. Data is being collected through questionnaires and audio-taped focus group discussions. Follow-up data will also be extracted from eMTCT registers at respective eMTCT sites. Data is kept in locked cabinets only accessible to the principal investigator and the supervisors.