Pregnancy complications and birth outcomes among women experiencing nausea only or nausea and vomiting during pregnancy in the Norwegian Mother and Child Cohort Study

Arthur Chortatos, Margaretha Haugen, Per Ole Iversen, Åse Vikanes, Malin Eberhard-Gran, Elisabeth Krefting Bjelland, Per Magnus, Marit B. Veierød

To compare pregnancy complications and birth outcomes for women experiencing nausea and vomiting in pregnancy, or nausea only, with symptom-free women. 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. 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). We found that women with NVP and NP are more likely to develop pregnancy complications, yet they display mostly favourable delivery and birth outcomes.