He will now lead an investigation into the deaths of Miss Nathan and her baby.
Action to Improve Maternity founder Jenn Hooper said she hoped the deaths would highlight the need to overhaul of the country's maternity system.
She has been campaigning for change since her own daughter Charley was left with severe cerebral palsy after a troubled birth in Morrinsville in 2005. Mrs Hooper also almost died after haemorrhaging.
She wants an independent review of the midwifery system under which midwives, rather than GP obstetricians, are lead maternity carers for most mothers-to-be, and an independent body to handle complaints against midwives.
She also wants an independent perinatal database to record every birth - not just those in hospitals - and how mother and baby fared.
This was the only way to get vital information needed to improve the maternity sector, she said.
Mrs Hooper presented a petition to Parliament's health select committee two weeks ago, in which she asked why similar recommendations by the committee in 2009 have not been actioned.
In July last year it was revealed in the perinatal and maternal mortality review committee that 98 newborn babies who died in 2009 could possibly have been saved.
Mrs Hooper was also concerned with Ministry of Health maternity transfer guidelines for lead maternity carers which did not consider problems including a baby having difficulty breathing or not breathing, or a mother who had lost 500ml of blood and was continuing to lose blood, as emergency situations during childbirth.
"Each one of those situations has killed people in the past and they can very quickly become life-threatening, each and every time."
AIM also wanted graduate midwives to spend up to two years in internships at tertiary or base hospitals instead of being able to go straight into the community.
Her calls came on the day Health Minister Tony Ryall announced $20.5 million to strengthen maternity services. That included $6.6 million for Plunketline and Wellchild for increasing volumes and staffing and cost pressures. Details of the maternity share would be announced later.
The New Zealand College of Midwives and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists New Zealand Committee would not comment on the case.