An increase in neural tube defects in South Australia, 2009-2010

Abstract

Introduction: An investigation was undertaken to determine the aetiology of increased notifications of neural tube defects, South Australia, 2009-2010, to assist with prevention efforts.

Methods: In South Australia reporting of live births; and still births of at least 20 weeks or 400 grams birth weight; termination of pregnancy procedures and congenital anomalies is mandated. Comparisons of pregnancies affected by a neural tube defect 2009-2010 were made with pregnancies affected by a neural tube defect 2003-2008; and all women with births 2009-2010. Neural tube defect trend data 1966-2010 were reviewed. Statistical analysis was undertaken using chi squared or Fisher’s exact tests.

Results: The prevalence of NTD affected pregnancies was 1.95 per 1000 births in 2010, the highest rate since 1991. Women with a NTD affected pregnancy in 2009-2010, compared with 2003-2008, were less likely to be Caucasian and more likely to take folic acid supplements. Women with a NTD affected pregnancy 2009-2010 compared with all women with births in 2009-2010 were more likely to be born in the Middle East; or Southern and Central Asia; and have used assisted reproductive therapy. Analysis by age, socioeconomic status, Indigenous status, plurality, gravidity, parity and early pregnancy exposure to high ambient temperatures was unremarkable.

Discussion: Although the aetiology of the increased notifications of neural tube defects was not discovered, areas where prevention efforts could be improved were identified, including for: women born in the Middle East and Southern and Central Asia; women of lower SES; and women who were multigravidas.