Background
For the first six months of life, breast milk is the ideal food to provide adequate quality and quantity of nutrients. Exclusive breastfeeding has a profound effect to reduce the risk of respiratory and gastrointestinal related morbidities as well as all-cause and infection-related neonatal mortalities. Despite the immense benefits of exclusive breastfeeding, the practice is suboptimal in Ethiopia. The aim of this study was to assess whether antenatal care and institutional delivery contributes to mothers' practice of exclusive breastfeeding in rural communities of northwest Ethiopia.

Methods
A community-based nested case–control study was conducted in northwest Ethiopia from November 2009 to August 2011. About 1769 mother-infant pairs were included and followed for six months after birth. Interviews with mothers were conducted in the first week, at 1st, 4th, and 6th month. Bivariate and multivariate logistic regression were carried out to determine associations between independent variables and exclusive breastfeeding practice.

Results
Of the total respondents, 30.7 % (95 % CI: 27 %, 35 %) of mothers exclusively breastfed their infants. In multivariate analysis, own business activity (AOR= 3.06; 95 % CI: 1.29, 7.25), being a housewife (AOR= 3.41; 95 % CI: 1.28, 9.11), having antenatal care (AOR= 1.32; 95 % CI: 1.01, 1.73), giving birth in a health institution (AOR= 1.29; 95 % CI: 1.02, 1.62), and possessing a microfinance bank account (AOR= 2.35; 95 % CI: 1.80, 3.07) were positively associated with exclusive breastfeeding practice.

Conclusions
Despite underutilization of maternal health services, these services contributed to mothers exclusive breastfeeding practice. Strengthening utilization of antenatal care and institutional delivery would have an added benefit in improving exclusive breastfeeding practice. Moreover involving mothers in business activities is important.