Migrant women who spend time immersing themselves in Australia are likely to experience better birth outcomes than new arrivals.

A study led by University of Western Australia researchers found newly arrived migrant women had a 60 per cent higher chance of delivering a low birth-weight, full-term baby than non-migrants.

And yet, the same group had a 50 per cent lower chance of delivering a premature baby than Australian-born women.

Both pre-term birth (before 37 weeks) and low birth-weight (less than 2.5kg) are categorised as adverse pregnancy outcomes that result in higher rates of mortality and morbidity.

The research team crunched the numbers on 250,000 babies delivered in WA from 2005 to 2013.

It compared women with non-Australian partners and who needed an interpreter with mothers who could speak English fluently and had an Australian partner.

Lead author Maryam Mozooni said the stress of immigration and unfamiliarity with the Australian healthcare system could explain some of the disparities.

She said a significantly higher chance of full-term, low birth-weight in migrant babies could be because they were not screened during pregnancy or did not receive the same level of medical care.

Migrant women surveyed as part of the study were less likely to smoke in pregnancy, less financially disadvantaged and had less pre-existing medical conditions than Australian-born women.

Dr Mozooni recommended better monitoring of fetal growth during pregnancy for recent migrants and appropriate interventions to improve birth-weight in full-term babies.

She said the findings, which could be extrapolated to the wider Australian population, underscore the need to better understand the health impacts of migration on mothers.