"In India, Muslim children are substantially more likely than Hindu children to survive until their fifth birthday, despite Muslim parents being poorer and less educated on average than Hindu parents. The phenomenon has been documented by numerous researchers over the past 20 years, including most recently by Bhalotra et al. (2010).
This pattern of Muslim child survival advantage is hard to reconcile with the well-developed body of work (summarised in Geruso 2012) on the importance of income and education in predicting health and mortality. In the context of India, these would predict a mortality disadvantage for Muslims. Nonetheless, by age five, mortality among Muslims is about 18% lower than among Hindus, with an additional 1.7 children per 100 surviving to age five."
While now sanitation is being cited as the cause, I would (from my visits to PHC's in Andhra Pradesh and interactions with doctors serving) like to mention the following points;
1. Muslims prefer natural birth even if the birth takes place in a PHC
2. Muslims either do not vaccinate or selectively vaccinate when under immense pressure
3. Muslims prefer the Unani system or the Hakims and tend to stay away from the dominant system
4. Muslims tend not to fuss too much over their children and allow them to grow up in a natural environment
5. Muslim mothers, like their Hindu counterpart, breastfeed their children with great care
In many ways, by staying away from the mainstream, the Muslims are the Amish of India.