AIHW media releases

An increasing number of Australian women postpone having their first baby until later in life, according to a report released today by the Australian Institute of Health and Welfare (AIHW).

Australia's Mothers and Babies 1999 shows the proportion of mothers having their first baby at 35 years or over has doubled in the past decade, from 1 in 20 first-time mothers in 1991 to 1 in 10 first-time mothers in 1999.

Correspondingly, 16% of all women giving birth in 1999 were aged 35 years and over, increasing from around 11% in 1991.

Professor Richard Henry, Head of the School of Women's and Children's Health at the University of New South Wales, said that these findings were consistent with other recent trends, including a higher proportion of births by caesarean section.

'Caesarean rates are higher among older mothers, those having their first baby, and private patients,' Professor Henry said.

'Almost one-third of older mothers had a caesarean section compared with about 20% of younger mothers. Half of these older mothers had private health insurance, and almost one-third were first-time mothers.'

Professor Henry also said that having children at a later age is associated with certain health risks. A greater proportion of mothers aged 35 years and older had babies that were of low birthweight (less than 2,500 g) or were born pre-term (less than 37 weeks gestation).

After teenage mothers (10.5 per 1,000 births), mothers over 35 years had the highest rate of stillbirths (8.3 per 1,000 births) in 1999.

Australia's Mothers and Babies 1999 presents data collected from the 257,394 births notified to State and Territory perinatal data collections in that year. Other findings include:

• The average age of all mothers in 1999 was 29.0 years, and 27.1 years for those having their first baby, continuing the upward trend of recent years.
• There were 12,983 teenage mothers in 1999 (5% of all mothers), of whom 4,115 were aged 17 years or younger. There was a higher proportion of teenage mothers among Indigenous mothers (22%).
• More mothers have relatively short postnatal stays in hospitals. The proportion who stayed less than 2 days increased from 3.2% in 1991 to 11.6% in 1999, while the proportion of those staying between two and four days increased from 35% to 55.4% in the same period.
• The rate of multiple pregnancies continued to rise, accounting for 1.6% of all confinements.