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
- Data are obtained from multiple sources. Table 1.1 details the number of notifications of birth defect cases for 2001 - 2002 births. The number of notifications exceeds the number of cases due to multiple reporting of cases from different sources.
- For the period 2001 - 2002 there were 7,556 notifications for a total of 4,873 cases. This approximates to 1.5 notifications per case.
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 | 0.0 |
| Total | 7,556 | 100.0 |
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 | 3.0 |
| 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 | 395.0 | 4.0 |
| 1995 | 63,717 | 2,495 | 255 | 429.9 | 4.3 |
| 1996 | 62,951 | 2,228 | 272 | 395.4 | 4.0 |
| 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 | 449.0 | 4.5 |
| 2000 | 62,564 | 2,477 | 288 | 439.9 | 4.4 |
| 2001 | 62,148 | 2,175 | 300 | 396.3 | 4.0 |
| 2002 | 63,072* | 2,098 | 300 | 378.4 | 3.8 |
| Total | 1,262,934 | 41,666 | 3551 | 357.0 | 3.6 |
Examples of information contained on 28 selected defects on Birth Defects in Victoria
Spina bifida
- British Paediatric Association code 741.00 - 741.99
- Definition: Non-closure of the spine resulting in herniation or exposure of the spinal cord and / or meninges. Hydrocephalus may or may not be present.
Trend in prevalence 1983-2002
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 | 10.0 | 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 | 10.0 |
| 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 | 100.0 |
| Pregnancy outcomes 2001-2002 | N | % | N/10,000(01-02) | N/10,000(97-02) |
|---|---|---|---|---|
| Survived > 28 days | 12 | 17.1 | 1.0 | 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 | 0.0 | ||
| Unknown | 3 | 4.3 | ||
| Infant 2001-2002 (n=70) | Prevalence Rate /10,000 | |||
|---|---|---|---|---|
| No. | % | (01-02) | (97-02) | |
| Plurality | ||||
| Singleton | 69 | 98.6 | 5.7 | 7.0 |
| Twin | 1 | 1.4 | 2.4 | 4.2 |
| Triplet | 0 | 0 | ||
| Quad | 0 | 0 | ||
| Maternal Characteristics (n=70) | ||||
|---|---|---|---|---|
| Maternal Age (yrs) | ||||
| < 20 | 3 | 4.3 | 7.7 | 8.3 |
| 20-24 | 9 | 12.9 | 6.0 | 11.1* |
| 25-29 | 18 | 25.7 | 5.2 | 8.2 |
| 30-34 | 22 | 31.4 | 4.9 | 4.8 |
| 35-39 | 14 | 20.0 | 6.7 | 6.0 |
| 40+ | 2 | 2.9 | 5.0 | 4.7 |
| Unknown | 2 | 2.9 | ||
| Maternal Characteristics (n=70) | ||||
|---|---|---|---|---|
| Country of Birth | ||||
| Australia | 49 | 70.0 | 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 | 8.0 |
| Asia | 2 | 2.9 | 1.7 | 2.6* |
| Nth America | 0 | 0.0 | 0.0 | 0.0 |
| Sth America | 0 | 0.0 | 0.0 | 4.8 |
| Africa | 3 | 4.3 | 14.5 | 9.3 |
| Unknown | 8 | 11.4 | ||
| 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 | 10.0 | 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 | 10.0 | 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 | ||
Prevalence of all neural tube defects (NTD) 1983-2002
Trisomy 21
- British Paediatric Association code 758.00 - 758.09
- Definition: Down syndrome - additional chromosome 21.
Trend in prevalence 1983 - 2002
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 | 16.0 | 16.7 | 16.8 | 17.0 | 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.