Like EXPOSURE1, EXPOSURE2 (V625) is a constructed variable that draws upon responses to several questions to distinguish between pregnant women, postpartum amenorrheic women, menopausal or infecund women, and fecund women. EXPOSURE2 uses a more liberal definition of infecundity than EXPOSURE1, however.
When children are chosen as the unit of analysis, the woman respondent indicates the mother of the child.
The DHS Recode Manuals explain the differences between these two variables as follows:
For Model "B" countries, it is only possible to say that a woman had been continuously married throughout the preceding five years if she was in her first union. This definition has been relaxed in V625 [EXPOSURE2], such that the respondent need only have been married at least five years ago, and not continuously married throughout the last five years. For Model "A" countries, there is no change to this part of the definition.
[For EXPOSURE2] Two additional variables have been used to declare a woman infecund. If the respondent said that she cannot get pregnant when asked about preferences for additional children, or if she reported that she was menopausal or had a hysterectomy when giving the reason she was not currently using a contraceptive method, the respondent is coded as infecund.
Model A countries and Model B countries are defined according to whether the country based its questionnaire on the Model A or Model B standard DHS questionnaire for DHS phases one through four. In general, the Model A questionnaire was designed for use in countries with high contraceptive prevalence. Nonetheless, countries with relatively low contraceptive prevalence sometimes modeled their own questionnaire on the Model A standard questionnaire. This was the case, for example, for the Kenyan samples for 1998 and 2003 and the Malawi samples for 2000 and 2004.