A call has been made to help disadvantaged mothers-to-be, in the wake of research on the level of care given by midwives.

LISTEN ABOVE: Former midwife and master of public health Ellie Wernham spoke to Larry Williams on the Mike Hosking Breakfast 

Otago University researchers have studied more than 244,000 pregnancy outcomes between 2008 and 2012.

They've found that mothers electing to have their baby with a doctor had 55 percent lower odds of their babies having oxygen deprivation during delivery, than those who chose midwives.

The report also finds that doctor-delivered babies had 39 percent lower odds of contracting a condition that could lead to brain injuries.

Research co-author Ellie Wernham said another key finding was that those living in the most deprived circumstances "had much higher rates of the outcomes that we looked at, and that included rates of babies being born stillborn, or dying in the first month of life."

Dr Ellie Wernham said they're surprised at the findings.

"Any difference between groups in terms of outcomes would be concerning, given the gravity of the outcomes that we looked at, so there was surprise at the level of difference between groups."

Midwives say the new research is proof that mothers are paying the price for under-funding within the maternity care sector.

College of Midwives chief executive Karen Guilliland said private maternity care is better funded, and their calls for funding equity for public maternity care is justified.

"If you add that with four reviews of DHB services over the last few years saying the same thing, I think the government and the DHBs need to talk to each other about prioritising mothers and babies."

Previous research suggests midwife-led care can lead to greater patient satisfaction and lower intervention rates.