Maternal Mortality Rate is calculated by

Maternal Mortality rate (MMR): Maternal deaths expressed as per 100,000 live births, where a ‘maternal death’ is defined as ‘death of a woman while pregnant or during delivery or within 42 days (6 weeks) of termination of pregnancy, irrespective of duration or site of pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.’ Maternal deaths expressed as per 100,000 live births (earlier it was expressed per 1000 live births but that yielded fractions like 4.08 maternal deaths per 1000 LB; so denominator was extrapolated to 100,000 to make MMR value more sensible.)