Table 1.

Definition of variables.

Variable	Description
Demographic
Age of Woman at Child's Birth	•Age of woman when most recent child was born
Age of Woman at Marriage	•Age of woman at her first marriage. •The child discussed in this study could be from a different or no marriage
Rural or Urban Place of Residence	•A categorical variable indicating whether a woman's usual residence is in an urban or rural area
Parity	•A count variable indicating which child from the eldest, in age order, the most recently born child is
Religion	•A categorical variable indicating which religion a woman follows •Options include Hindu, Muslim, Christian, Sikh, and Other
Socioeconomic
Wealth Index	•A count variable from 1 to 5 that indicates the wealth of a woman's household •It is based on the number and kind of consumer goods a household owns. •This variable is from the Household Questionnaire of the NFHS-4
Woman's Educational Attainment	•A categorical variable indicating the highest level of education attended •Options include no education, primary, secondary, or higher
Caste or Tribe Membership	•A categorical variable for what type of caste or tribe a woman belongs to •Options include scheduled caste, scheduled tribe, other backwards class, or none of them
Exposure – Receiving Antenatal Care from a Community Health Worker
Any Community Health Worker	•A binary variable for whether or not a woman received antenatal care from any community health worker for her most recent pregnancy •Any community health worker encompasses ASHAs, AWWs, and other community health workers
ASHA	•A binary variable for whether or not a woman received antenatal care from an ASHA for her most recent pregnancy
AWW	•A binary variable for whether or not a woman received antenatal care from an AWW for her most recent pregnancy
Other Community Health Worker	•A binary variable for whether or not a woman received antenatal care from other community health workers for her most recent pregnancy •Other community health worker is defined in the NFHS-IV Woman's Questionnaire as a “community/village health worker” who is not an ASHA, Anganwadi worker, or a DAI/Traditional Birth Attendant
Outcomes – Antenatal and Infant Health
Antenatal Care Utilization	•A binary variable for whether or not a woman attended at least four ANC visits, which was the WHO recommendation and the focus of Indian public health programs at the time of NFHS-4. (WHO, 2013) •In a sensitivity analysis, utilization was redefined as a binary variable for whether or not a woman had eight or more ANC visits, as this is the updated 2016 WHO recommendation. (WHO, 2013) •In a sensitivity analysis, utilization was redefined as a count variable for number of ANC visits.
Quality of Antenatal Care	•A count variable from 0 to 11 that is a composite of 11 binary questions about a woman's pregnancy. A higher score indicates higher quality. •5 of the questions were: “As part of your antenatal care during this pregnancy, were any of the following done at least once? a) Were you weighed? b) Was your blood pressure measured? c) Did you give a urine sample? d) Was a sample of your blood taken for testing? e) Was your abdomen examined?” 5 of the questions were “During (any of) your antenatal care visit(s), were you told about the following signs of pregnancy complications? a) vaginal bleeding? b) convulsions? c) prolonged labour? d) severe abdominal pain? e) high blood pressure?” The last question was: “Were you told where to go if you had any pregnancy complications?” (Woman's Questionnaire, 2015)
Birthweight	•A continuous variable for the weight of a woman's newborn in grams •Birthweight was obtained either from a birth card or mother's recall
Early Initiation of Breastfeeding	•A binary variable for whether or not a mother initiated breastfeeding for her newborn immediatelya
One-Year Mortality	•A binary variable for whether or not a mother's infant died within one year of birth

All variables were obtained from the Woman's Questionnaire of the National Family Health Survey 4 except for wealth index, which was obtained from the Household Questionnaire.

^a“Immediately” was a measure for time to initiation of breastfeeding in the data but does not represent a specific time interval.