Motherhood trends affect baby health

A detailed 16-year study of every birth in Victoria gives a fascinating snapshot on motherhood trends and its effect on the health and wellbeing of babies, says Health Minister John Thwaites.

Releasing the study, Birth Defects in Victoria 1983–1998, Mr Thwaites said the study showed important shifts that would be used to plan services for mothers and babies.

Undertaken by the Perinatal Data Collection Unit of the Human Services Department, the study found 3.4 per cent of babies had a birth defect, with the rate climbing from 2.8 per cent in 1983 to 3.6 per cent in 1998.

‘A number of factors have contributed to the apparent increase in defects in recent years including an increased number of women postponing having children until they are older,’ Mr Thwaites said.

The study found women aged over 35 are 1.34 times more likely to have a pregnancy affected by a birth defect than younger mothers, while teenage mothers have a significantly increased risk of babies with spina bifida (non-closure of the spine), hydrocephalus (dilation of the ventricular system) and gastroschisis.

Other key trends found:

• Mothers from rural Victoria, who are generally younger, were less likely to have a baby born with a malformation than city mothers;

• Aboriginal mothers have significantly fewer babies with birth defects than non-Aboriginal mothers.

• Congenital dislocation of the hip is a common defect—at one for every 350 births—with female babies having a fourfold risk over male babies.

• Significant gender differences in defects, with males at higher risk of Down Syndrome, cardiac and renal abnormalities and females at increased risk of anencephaly (the total or partial absence of the cranial covering skin and brain tissue), cleft palate and congenital hip dislocation.

Except for women aged less than 20, the report found the prevalence of birth defects increased with age.

The overall prevalence of Down Syndrome has increased, because of the greater number of older women becoming pregnant, the research found.

For the first time in 1998 there was a substantial decline in both anencephaly and spina bifida.

‘We would want to see whether this is an ongoing trend or just a chance fluctuation but it could well be the result of a sustained campaign to encourage intending mothers to increase their intake of folate,’ Mr Thwaites said.

The number of babies born with spina bifida in Victoria in 1998 was fewer than 10—compared with 21 in 1997, 31 in 1990 and 49 in 1983.

‘Victoria has been at the forefront in encouraging the taking of the B-group vitamin due to its link to preventing spinal cord defects such as spina bifida in babies.

‘The best ways to achieve this are to take a supplement each day as part of a woman’s daily routine or eat folate-fortified foods such as cereals.

‘It could well be that intending mothers have embraced the folate campaign and the results are already starting to show.’

The study involved 34,847 cases of defects over the 16-year period, which covered 1,012,461 births.

‘The results of this study will help in the planning for specialist hospital-based services such as genetic counsellors, antenatal carers, neonatal intensive care units, special care nurseries, paediatricians and both hospital and community support services,’ Mr Thwaites said.

• The report is available on the internet at www.dhs. vic.gov.au/phd/0006114/index.htm or through the Perinatal Data Unit at GPO Box 4003 Melbourne 3001.