Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2002 Aug 6;167(3):237-40.

Incidence of neural tube defects in Ontario, 1986-1999

Enza Gucciardi  1 , Mary-Anne Pietrusiak, Donna L Reynolds, Jocelyn Rouleau
Affiliations

Incidence of neural tube defects in Ontario, 1986-1999

Enza Gucciardi et al. CMAJ. .

Abstract

Background: Prenatal screening and the promotion of folic acid intake could affect the incidence of neural tube defects (NTDs). We examined trends in the total NTD incidence, as detected in live births, stillbirths and therapeutic abortions, from 1986 to 1999 in Ontario.

Methods: To capture cases of NTDs we used data from the Canadian Congenital Anomalies Surveillance System and hospital data on therapeutic abortions. We calculated the total incidence of NTDs by combining the numbers of NTDs occurring in live births, stillbirths and therapeutic abortions.

Results: The total NTD incidence rate increased from 11.7 per 10,000 pregnancies in 1986 to 16.2 per 10,000 in 1995, and it subsequently decreased to 8.6 per 10,000 by 1999. The NTD birth rate (live births and stillbirths) decreased from 10.6 per 10,000 births in 1986 to 5.3 per 10,000 in 1999. The rate of therapeutic abortions with an NTD or hydrocephalus rose from 17.5 per 10,000 abortions in 1986 to 50.7 per 10,000 in 1995 and fell to 28.7 per 10,000 abortions in 1999.

Interpretation: The total NTD incidence rate increased from 1986 to 1995, probably because of increased prenatal screening and better detection of NTDs. The decline from 1995 to 1999 may have been due to increased folic acid intake among women at the time of conception.

PubMed Disclaimer

Figures

None
Fig. 1: Total incidence rates of neural tube defects (NDTs) and birth incidence rates of NTDs and hydrocephalus in Ontario, 1986–1999.
None
Fig. 2: Incidence rates of NTDs in live births, by type of NTD.
None
Fig. 3: Incidence rates of NTDs in stillbirths, by type of NTD.
None
Fig. 4: Incidence rates of NTDs or hydrocephalus in therapeutic abortions.
None
Fig. 5: Distribution of live births, stillbirths and therapeutic abortions with NTDs.
See this image and copyright information in PMC

Comment in

References

    1. Moore KL. The developing human: clinically oriented embryology. 3rd ed. Philadelphia: W.B. Saunders Company; 1982. p. 385-403.
    1. Infant health: measuring up. A health surveillance update on Canadian children and youth. Ottawa: Health Canada; 1999. Cat no H42-2/82-1999E. - PMC - PubMed
    1. Johnson KC, Rouleau J. Temporal trends in Canadian birth defects birth prevalence. Can J Public Health 1997;88(3):169-76. - PMC - PubMed
    1. Canadian Perinatal Surveillance System: induced abortion [fact sheet]. Ottawa: Health Canada; 1998.
    1. Chan A, Robertson EF, Haan EA, Keane RJ, Ranieri E, Carney A. Prevalence of neural tube defects in South Australia, 1966–91: effectiveness and impact of prenatal diagnosis. BMJ 1993;307:703-6. - PMC - PubMed

Publication types