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Birth defects in Victoria

Page content: Sources of notification | Birth defects by year, 1983-2002 | Examples of information contained on 28 selected defects on Birth Defects in Victoria

The following and further information on birth defects cases by selected infant and maternal factors, and major birth defects, is available in Births Defects in Victoria 2001-2002.

Birth Defects in Victoria 2003-2004 is due for publication late 2006.

Sources of notification

Table 1.1 Sources of notification, 2001 - 2002

Notification source Number Percent(%)
Victorian Perinatal Data Collection (VPDC) - perinatal form 3,640 48.2
Hospital listing 2,562 33.9
Perinatal death certificate 365 4.8
Autopsy report 179 2.4
Cytogenetics report 555 7.3
Maternal and child health nurse 208 2.8
Other professional 26 0.3
Other (e.g. parent) 19 0.3
Unknown 2 0
Total 7,556 100

Birth defects by year, 1983-2002

The overall birth prevalence of birth defects for the 20 years data have been available is 357/10,000 or 3.6%. The increase until 1990 probably reflects improving ascertainment, but the fluctuations since 1990 are more likely to reflect "true prevalence", as the methods of ascertainment since then have been the same. From 1995-1998 the overall prevalence was 415.5/10,000 (4.1%), for 1999-2000 the overall prevalence was 444.5/10,000 (4.4%) and for 2001-2002 it was 387.3/10,000 (3.9%).

Table 2.1 Birth defects by year, 1983-2002

Year Total births, 20 weeks and later Defects, 20 weeks and later Defects before 20 weeks (terminations) N/10,000 Pregnancies (including terminations) %
1983 60,628 1,637 2 270.3 2.7
1984 60,737 1,659 9 274.6 2.7
1985 61,189 1,571 17 259.5 2.6
1986 61,253 1,572 80 269.3 2.7
1987 61,566 1,592 55 267.3 2.7
1988 63,666 1,832 103 303.4 3
1989 64,255 1,935 122 319.5 3.2
1990 66,878 2,135 133 338.5 3.4
1991 65,248 2,223 140 361.4 3.6
1992 66,305 2,284 152 366.6 3.7
1993 64,737 2,241 203 376.3 3.8
1994 64,932 2,325 250 395 4
1995 63,717 2,495 255 429.9 4.3
1996 62,951 2,228 272 395.4 4
1997 62,308 2,336 298 420.7 4.2
1998 62,091 2,319 276 416.1 4.2
1999 62,689 2,532 296 449 4.5
2000 62,564 2,477 288 439.9 4.4
2001 62,148 2,175 300 396.3 4
2002 63,072* 2,098 300 378.4 3.8
Total 1,262,934 41,666 3551 357 3.6

*This figure differs from the number of births presented in Births in Victoria 2001-200212 due to the inclusion of 3 terminations of pregnancy greater than 20 weeks that were excluded from that previous report.

Examples of information contained on 28 selected defects on Birth Defects in Victoria

Spina bifida

Trend in prevalence 1983-2002

Trend in prevalence 1983-2002

Number of cases and pregnancy outcomes 1989-2002

Spina bifida - Number of cases and pregnancy outcomes 1989-2002

Number 55 59 49 49 51 60 64 51 60 32 50 43 37 33
Prevalence Rate /10,000 8.5 8.8 7.5 7.4 7.9 9.2 10 8.1 9.6 5.1 7.9 6.8 5.9 5.2

Spina Bifida and associated birth defects, 2001-2002

Type of birth defect TOP < 20 weeks Stillbirth Neonatal death Surviving > 28 days Total % of Total
Isolated 22 8 6 7 43 61.4
Chromosomal 6 1 0 0 7 10
Other same system (CNS) 2 1 0 0 3 4.3
Other different system 3 6 3 5 17 24.3
Total 33 16 9 12 70 100

Pregnancy outcomes 2001-2002 N % N/10,000(01-02) N/10,000(97-02)
Survived > 28 days 12 17.1 1 1.5
Neonatal death 9 12.9    
Stillbirth 16 22.9    
TOP < 20 weeks 33 47.1    

Spina bifida and selected infant and maternal characteristics

Infant 2001-2002 (n=70) Prevalence Rate /10,000
  No. % (01-02) (97-02)
Sex        
Male 41 58.6 6.4 6.8
Female 26 37.1 4.3 5.5
Indeterminate 0 0  
Unknown 3 4.3  
No significant association

Infant 2001-2002 (n=70) Prevalence Rate /10,000
  No. % (01-02) (97-02)
Plurality        
Singleton 69 98.6 5.7 7
Twin 1 1.4 2.4 4.2
Triplet 0 0  
Quad 0 0  
No significant association
Maternal Characteristics (n=70)
Maternal Age (yrs)        
< 20 3 4.3 7.7 8.3
20-24 9 12.9 6 11.1*
25-29 18 25.7 5.2 8.2
30-34 22 31.4 4.9 4.8
35-39 14 20 6.7 6
40+ 2 2.9 5 4.7
Unknown 2 2.9  
PR for women aged 20-24 years is significantly higher than those aged 30-39 years.

Maternal Characteristics (n=70)
Country of Birth        
Australia 49 70 5.2 6.9
Oceania inc NZ 2 2.9 6.1 9.8
UK inc Eire 2 2.9 5.4 5.5
Europe 2 2.9 4.9 3.8
Middle East 2 2.9 7.2 8
Asia 2 2.9 1.7 2.6*
Nth America 0 0 0 0
Sth America 0 0 0 4.8
Africa 3 4.3 14.5 9.3
Unknown 8 11.4  
PR for Asian-born women is significantly less than that for Australian-born women.

Maternal Characteristics (n=70)
Region        
Barwon S W 2 2.9 2.5 5.3
Grampians 2 2.9 4.1 8.6
Loddon Mallee 7 10 9.8 6.4
Hume 4 5.7 6.5 7.5
Gippsland 5 7.1 9.2 8.3
Western Metro 6 8.6 3.5 6.8
Northern Metro 7 10 3.3 5.5
Eastern Metro 12 17.1 5.4 6.7
Southern Metro 20 28.6 6.9 7.8
Other/Unknown 5 7.1  
No significant associations.

Prevalence of all neural tube defects (NTD) 1983-2002

Prevalence of all neural tube defects (NTD) 1983-2002

Trisomy 21

Trend in prevalence 1983 - 2002

Trend in prevalence 1983 - 2002

Number of cases and pregnancy outcomes 1989 - 2002

Trisomy 21 - Number of cases and pregnancy outcomes 1989 - 2002

Number 103 112 110 113 111 127 138 107 147 134 166 162 177 178
Prevalence Rate /10,000 16 16.7 16.8 17 17.1 19.5 21.6 16.9 23.5 21.5 26.4 25.8 28.4 28.1

For further information on Spina bifida, Trisomy 21 and other birth defects is available in Births Defects in Victoria 2001-2002.