Research: What causes women in New South Wales to birth before arrival, and why?

By Louise Webster on 03 September 2018 Midwives Magazine Australia Research Birth Before Arrival BBA

Birthing options in Australia are more numerous in densely populated coastal regions but less available in rural and remote areas, often necessitating some women to move to city regions as their birth due date draws near.

In Australia, rural and remote maternity units are regularly shut down and obstetric intervention continues to rise. This prompted us to investigate whether women are increasingly likely to birth before arrival into a maternity unit and whether some of these births may actually be freebirths.

There are anecdotal accounts that freebirth is increasing in Australia, however there is no official collection of data. We proposed that the freebirth rate could be estimated through examining data on babies born before arrival (BBA) and seeing whether these events occurred more often in geographic areas where home birth was also more prevalent.

Using population-based linked data we looked at all births in New South Wales (NSW) between the years 2000-11. The Perinatal Data Collection in NSW records births which occur before arrival, which were not intended home births. This surveillance system also records maternal postcode, which always asks for a socioeconomic profile of women to be established and geographical settings to be examined.

During the time period, there were 1,097,653 births and a BBA rate of 4.6 per 1000 births. The BBA rate changed from 4.2 to 4.8 per 1000 births over time (p=0.06). Babies BBA were more likely to be premature (12.5% compared with 7.3%), of lower birthweight (209.8g mean difference) and be admitted to a special care nursery or NICU (20.6% compared with 15.6%). The perinatal mortality rate was significantly higher in the BBA cohort (34.6 compared with 9.3 per 1000 births). Women in the BBA cohort were more likely to be in the lowest socioeconomic decile, multiparous, have higher rates of smoking (30.5% compared with 13.8%) and were more likely to suffer a postpartum haemorrhage requiring transfusion than the non-BBA cohort (1.5% compared with 0.7%). The most common occurring complications for neonates were suspected infection (6.9%), hypothermia (6.9%), respiratory distress (5.4%), congenital abnormality (4.0%) and neonatal withdrawal symptoms (2.4%). BBA occurred more in areas where the distance to a maternity unit is more than two hours’ drive and in coastal regions where there is also a high rate of home birth.

Three forces appeared to be at play in the occurrence of a BBA event: geographical distance, maternal socioeconomic factors and a correlation between home birth and BBA, which we propose is a proxy measurement of freebirth. Women need to be provided with options of care that meet their needs regardless of geography or socioeconomic status.

Charlene Thornton is associate professor of midwifery at Flinders University, Australia.