Journal of Applied Genetics

, Volume 47, Issue 2, pp 151–158

The impact of prenatal diagnosis on neural tube defect (NTD) pregnancy versus birth incidence in British Columbia

  • Margot I. Van Allen
  • Erin Boyle
  • Paul Thiessen
  • Deborah McFadden
  • Douglas Cochrane
  • G. Keith Chambers
  • Sylvie Langlois
  • Patricia Stathers
  • Beverly Irwin
  • Elizabeth Cairns
  • Patrick MacLeod
  • Marie -France Delisle
  • Soo -Hong Uh
Article

DOI: 10.1007/BF03194615

Cite this article as:
Van Allen, M.I., Boyle, E., Thiessen, P. et al. J Appl Genet (2006) 47: 151. doi:10.1007/BF03194615

Abstract

The birth incidence of neural tube defect (NTD) cases in British Columbia (B.C.), and elsewhere in North America, is reported to be declining. This decline is being attributed to folic acid (FA) supplementation and food fortification, but 2nd trimester prenatal screening of pregnancies for NTDs and other congenital anomalies has increased during this timeframe, as well. This descriptive, population-based study evaluates the impact of prenatal screening of NTD-affected pregnancies on (1) pregnancy outcome and (2) reporting of NTD births to the provincial Health Status Registry (B.C.H.S.R.); and it assesses (3) the use of periconceptional FA supplementation. NTD cases were ascertained from medical records of health centres providing care to families with NTD-affected pregnancies and newborns; and from NTD cases reported to the B.C.H.S.R. In 1997–1999, the B.C.H.S.R. published a NTD incidence of 0.77/1000. In this study, 151 NTD-affected pregnancies were identified, with an incidence of 1.16/1000. Partial Reporting of induced abortions in a NTD incidence 45.5% low than the actual incidence. Medical records were available for review on 144/151 pregnancies. Prenatal screening identified 86.1% (124/144) of NTD-affected pregnancies, with 72.6% (90/124) resulting in pregnancy termination, and 27.4% (34/124) continuing to term. Use of FA supplementation in the periconceptional period was recorded in 36.4% of pregnancies (39/107). Thus in B.C. the decline in the NTD incidence is due predominantly to pregnancy terminations following prenatal diagnosis, which reduces the NTD incidence by 60%, from 1.16/1000 to 0.47/1000. Continued efforts for primary and the option of secondary prevention of NTDs are recommended in order to improve newborn health in B.C. and elsewhere. These interventions need to be monitored, however, for optimal health care planning.

Key words

anencephalyB.C. Health Status Registrybirth defects registryfolic acidincidence of NTDsneural tube defectsNTD pregnancy outcomeprenatal diagnosis of NTDsprevention of NTDsspina bifida

Copyright information

© Institute of Plant Genetics, Polish Academy of Sciences, Poznan 2006

Authors and Affiliations

  • Margot I. Van Allen
    • 1
  • Erin Boyle
    • 1
  • Paul Thiessen
    • 2
  • Deborah McFadden
    • 3
  • Douglas Cochrane
    • 4
  • G. Keith Chambers
    • 5
  • Sylvie Langlois
    • 1
  • Patricia Stathers
    • 1
  • Beverly Irwin
    • 2
  • Elizabeth Cairns
    • 1
  • Patrick MacLeod
    • 6
  • Marie -France Delisle
    • 7
  • Soo -Hong Uh
    • 8
  1. 1.Department of Medical GeneticsChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  2. 2.Department of PediatricsChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  3. 3.Department of PathologyChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  4. 4.Department of SurgeryChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  5. 5.Department of Family MedicineChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  6. 6.Department of Medical GeneticsVictoria General HospitalVictoria
  7. 7.Department of PerinatologyChildren’s and Women’s Health Centre and the University of British ColumbiaVancouver
  8. 8.B.C. Health Status RegistryVictoriaUSA
  9. 9.Department of Medical GeneticsUniversity of British ColumbiaVancouverCanada, USA