title: Seasonality of spina bifida in Northern Germany.
abstract: OBJECTIVE
  To verify a seasonal variation in the incidence of spina bifida and thus to identify possible environmental triggers leading to its developement.
  
  
  METHODS
  An interdisciplinary approach has been taken to develop a better understanding of spina bifida through collaborative efforts from investigators specializing in genetics, fetal pathology, paediatrics, neuro-surgery and prenatal ultrasonographic diagnosis. All pregnancies with fetal spina bifida were retrospectively analyzed from May 1 1993 through May 1 2010 at Luebeck University Fetal Health Center. Results were used to construct a model to predict the occurrence of fetal spina bifida based on seasonal variation and environmental influence reflected by climatic changes and environmental pollution. Furthermore, data were categorized in respect to the date of conception and subdivided into date of conception during summer (April-September) and winter months (October-March).
  
  
  RESULTS
  Neither a seasonal distribution of conception for fetuses with spina bifida in the defined time frame could be verified nor a relevant influence of the analyzed environmental factors on the prevalence of spina bifida could be proved. The incidence of spina bifida has remained relatively stable within the last 17 years at 2.5 per 1,000 screened pregnancies.
  
  
  CONCLUSIONS
  Since we were unable to demonstrate a relationship between seasonal variation and certain environmental factors on the incidence of fetal spina bifida, other factors should be investigated for a possible association with the onset of fetal spina bifida.
authors.affiliation: Department of Obstetrics and Gynaecology, Schleswig-Holstein University, Campus Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany. daniel.beyer@uk-sh.de
authors.forename: D A
authors.initials: DA
authors.lastname: Beyer
authors.forename: K
authors.initials: K
authors.lastname: Diedrich
authors.forename: J
authors.initials: J
authors.lastname: Weichert
authors.forename: A
authors.initials: A
authors.lastname: Kavallaris
authors.forename: F
authors.initials: F
authors.lastname: Amari
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D018811:Maternal Exposure / Q000009:adverse effects; D008875:Middle Aged; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012621:Seasons; D016135:Spinal Dysraphism / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult