title: Pregnancy complications and birth outcomes among women experiencing nausea only or nausea and vomiting during pregnancy in the Norwegian Mother and Child Cohort Study.
abstract: BACKGROUND
  To compare pregnancy complications and birth outcomes for women experiencing nausea and vomiting in pregnancy, or nausea only, with symptom-free women.
  
  
  METHODS
  Pregnancies from the Norwegian Mother and Child Cohort Study (n = 51 675), a population-based prospective cohort study, were examined. Data on nausea and/or vomiting during gestation and birth outcomes were collected from three questionnaires answered between gestation weeks 15 and 30, and linked with data from the Medical Birth Registry of Norway. Chi-squared tests, one way analysis of variance, multiple linear and logistic regression analyses were used.
  
  
  RESULTS
  Women with nausea and vomiting (NVP) totalled 17 070 (33%), while 20 371 (39%) experienced nausea only (NP), and 14 234 (28%) were symptom-free (SF). When compared to SF women, NVP and NP women had significantly increased odds for pelvic girdle pain (adjusted odds ratio, aOR, 2.26, 95% confidence interval, 95% CI, 2.09-2.43, and aOR 1.90, 95% CI, 1.76-2.05, respectively) and proteinuria (aOR 1.50, 95% CI 1.38-1.63, and 1.20, 95% CI 1.10-1.31, respectively). Women with NVP also had significantly increased odds for high blood pressure (aOR 1.40, 95% CI 1.17-1.67) and preeclampsia (aOR 1.13, 95% CI 1.01-1.27). Conversely, the NVP and NP groups had significantly reduced odds for unfavourable birth outcomes such as low birth weight infants (aOR 0.72, 95% CI 0.60-0.88, and aOR 0.73, 95 % CI 0.60-0.88, respectively) and small for gestational age infants (aOR 0.78, 95% CI 0.73-0.84, and aOR 0.87, 95% CI 0.81-0.93, respectively).
  
  
  CONCLUSIONS
  We found that women with NVP and NP are more likely to develop pregnancy complications, yet they display mostly favourable delivery and birth outcomes.
authors.affiliation: Oslo Centre for Biostatistics and Epidemiology, Institute of Basic Medical Sciences, University of Oslo, PO Box 1122, Blindern, N-0317, Oslo, Norway. athanasc@medisin.uio.no.|Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046, Blindern, N-0317, Oslo, Norway. athanasc@medisin.uio.no.
authors.forename: Arthur
authors.initials: A
authors.lastname: Chortatos
authors.affiliation: Division of Environmental Medicine, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. Margaretha.Haugen@fhi.no.
authors.forename: Margaretha
authors.initials: M
authors.lastname: Haugen
authors.affiliation: Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046, Blindern, N-0317, Oslo, Norway. p.o.iversen@medisin.uio.no.|Department of Hematology, Oslo University Hospital, PO Box 4950, Nydalen, N-0424, Oslo, Norway. p.o.iversen@medisin.uio.no.
authors.forename: Per Ole
authors.initials: PO
authors.lastname: Iversen
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. AseVigdis.Vikanes@fhi.no.
authors.forename: Åse
authors.initials: Å
authors.lastname: Vikanes
authors.affiliation: Department of Psychosomatics and Health Behaviour, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. megr@fhi.no.|Health Services Research Unit, Akershus University Hospital, PO Box 1000, N-1478, Lørenskog, Norway. megr@fhi.no.
authors.forename: Malin
authors.initials: M
authors.lastname: Eberhard-Gran
authors.affiliation: Department of Psychosomatics and Health Behaviour, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. ElisabethKrefting.Bjelland@fhi.no.|Health Services Research Unit, Akershus University Hospital, PO Box 1000, N-1478, Lørenskog, Norway. ElisabethKrefting.Bjelland@fhi.no.
authors.forename: Elisabeth Krefting
authors.initials: EK
authors.lastname: Bjelland
authors.affiliation: Division of Epidemiology, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403, Oslo, Norway. Per.Magnus@fhi.no.
authors.forename: Per
authors.initials: P
authors.lastname: Magnus
authors.affiliation: Oslo Centre for Biostatistics and Epidemiology, Institute of Basic Medical Sciences, University of Oslo, PO Box 1122, Blindern, N-0317, Oslo, Norway. m.b.veierod@medisin.uio.no.|Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046, Blindern, N-0317, Oslo, Norway. m.b.veierod@medisin.uio.no.
authors.forename: Marit B
authors.initials: MB
authors.lastname: Veierød
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016014:Linear Models; D016015:Logistic Models; D048968:Morning Sickness / Q000453:epidemiology*; D009325:Nausea / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D016017:Odds Ratio; D059388:Pelvic Girdle Pain / Q000453:epidemiology*; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011446:Prospective Studies; D011507:Proteinuria / Q000453:epidemiology*; D014839:Vomiting / Q000453:epidemiology*; D055815:Young Adult