A mother in her 50s who conceived after IVF treatment has given
birth to triplets in Adelaide, it was widely reported today. In
response to requests for information about other births to older
parents, the AIHW National Perinatal Statistics Unit at the
University of New South Wales has analysed available data from the
national register on assisted conception and from birth
registrations to determine what proportion of all births to older
parents occur after assisted conception (IVF and GIFT) and to
provide some information on pregnancy outcome.
Commenting on these findings, the Unit's Director, Associate
Professor Paul Lancaster, said 'while IVF and other types of
assisted conception have increased the number of births at older
parental ages, the majority of births to these older parents (more
than 90%) are still conceived naturally.
'With increasing age, donor eggs or sperm are more likely to be
used to achieve conception. Among women who become pregnant after
assisted conception in their 40s or 50s, about 50-60% go on and
have a liveborn infant. We still lack information on how many
births to parents of all ages occur after fertility drugs or
artificial insemination.'
The key findings are as follows:
- In recent years (1994-1996), an increasing proportion of all
mothers giving birth in Australia are aged 40 or more. In 1996,
there were 5,145 (2.1%) mothers in this age group. There were 155
(0.06%) mothers aged 45-49 years and 11 aged 50 or more.
- Paternal age is also increasing. In 1996, 1 in 10 fathers of
all children born in Australia was aged 40 or more, 1 in 100 was 50
or more, and 1 in 1,000 was 60 or more.
- Infertile couples treated by assisted conception (IVF and GIFT)
are well known to be older than couples who conceive
naturally.
- In 1994-95, 1 in 25 (3.9%) of all births to mothers aged 40 or
more followed assisted conception, increasing from 1 in 27 (3.7%)
at 40-44 years to 1 in 12 (8.3%) at 45 or more.
- In 1994-95, the father was 40 or more for 36,777 births. Of
these births, 1 in 37 (2.7%) resulted from assisted conception. The
proportion of all births in Australia that occurred after assisted
conception increased slightly with paternal age from 2.5% at 40-44
to 3.0% at 45-49 and 3.9% at 50-54, then declined again to 2.4% at
55-59 and 1.6% of those aged 60 or more.
- After assisted conception, 55.4% of 1,084 pregnancies to women
aged 40-44 years resulted in live births. Among 54 women aged 45
and over, 44.6% of their pregnancies resulted in live births.
- Among more than 16,000 pregnancies resulting in births after
assisted conception in Australia since 1979, 1,176 mothers were
aged 40 or more (Table 1) and 3,256 fathers were aged 40 or more
(Table 2).
- After assisted conception in Australia, the oldest mother
giving birth was 56; the oldest mother of twins was 48; and the
previous oldest mother of triplets was 43 years (Table 1). The
oldest father of an infant born after assisted conception was in
his 70s (Table 2).
2 June 1998
Further information: Associate Professor Paul
Lancaster, ph. 02 9382 1047, 02 9427 0112 (ah) or 02 9382 1025
(fax).
Availability: Check the AIHW Publications Catalogue
for details.