Alies Coenders1, Nienke K Koopmans1, Kim Broekhuijsen2, Henk Groen3, Janna M A Karstenberg-Kramer4, Kim van Goor4, Mariette Groenewout1, Aren J van Loon2, Marijke M Faas4, Maria G van Pampus5. 1. University of Groningen, University Medical Center Groningen, Department of Obstetrics and Gynecology, Groningen, The Netherlands. 2. Martini Hospital Groningen, Department of Obstetrics and Gynecology, Groningen, The Netherlands. 3. University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, The Netherlands. 4. University of Groningen, University Medical Center Groningen, Department of Pathology and Medical biology, Section Medical biology, Groningen, The Netherlands. 5. Onze Lieve Vrouwe Gasthuis, Department of Obstetrics and Gynecology, PO Box 95500, 1090 HM Amsterdam, The Netherlands. Electronic address: m.g.vanpampus@olvg.nl.
Abstract
OBJECTIVE: During the H1N1/09 pandemic, pregnant women in the Netherlands were vaccinated with an adjuvanted vaccine. During pregnancy, the maternal immune system changes to enable placental development and growth and acceptance of the semi-allogeneic fetus. As an adjuvant is a pro-inflammatory substance, it may interfere with these immunological changes, resulting in poor placentation or placental growth, which may result in preeclampsia (PE) and fetal intra-uterine growth restriction (IUGR). This study investigated a possible association between adjuvanted H1N1/09 vaccination and the development of PE and/or IUGR. STUDY DESIGN: Case-control study. Cases were Dutch women with PE and/or IUGR occurring during H1N1/09 vaccination program. Controls had uncomplicated pregnancies during the same period. Maternal characteristics, pregnancy and neonatal outcomes were collected from medical files. Participants were contacted by telephone to enquire about vaccination. Data were analyzed using t-tests, Chi-square tests or Fisher's exact tests. Multivariate analysis was conducted to control for confounders. RESULTS: We included 254 cases and 247 controls. Of the cases, 90 (35.4%) were vaccinated, compared to 87 (35.2%) of the controls (OR:1.009, 95% CI:0.70-1.46, p:0.961). The majority (73.5%) had been vaccinated in second and third trimester. In multivariate analysis, there were no confounders influencing these results. Exploratory subgroup analysis did not show an association between vaccination status in subgroups of women with either PE or IUGR. CONCLUSION: Our study showed no association between adjuvanted H1N1/09 vaccination and PE and/or IUGR.
OBJECTIVE: During the H1N1/09 pandemic, pregnant women in the Netherlands were vaccinated with an adjuvanted vaccine. During pregnancy, the maternal immune system changes to enable placental development and growth and acceptance of the semi-allogeneic fetus. As an adjuvant is a pro-inflammatory substance, it may interfere with these immunological changes, resulting in poor placentation or placental growth, which may result in preeclampsia (PE) and fetal intra-uterine growth restriction (IUGR). This study investigated a possible association between adjuvanted H1N1/09 vaccination and the development of PE and/or IUGR. STUDY DESIGN: Case-control study. Cases were Dutch women with PE and/or IUGR occurring during H1N1/09 vaccination program. Controls had uncomplicated pregnancies during the same period. Maternal characteristics, pregnancy and neonatal outcomes were collected from medical files. Participants were contacted by telephone to enquire about vaccination. Data were analyzed using t-tests, Chi-square tests or Fisher's exact tests. Multivariate analysis was conducted to control for confounders. RESULTS: We included 254 cases and 247 controls. Of the cases, 90 (35.4%) were vaccinated, compared to 87 (35.2%) of the controls (OR:1.009, 95% CI:0.70-1.46, p:0.961). The majority (73.5%) had been vaccinated in second and third trimester. In multivariate analysis, there were no confounders influencing these results. Exploratory subgroup analysis did not show an association between vaccination status in subgroups of women with either PE or IUGR. CONCLUSION: Our study showed no association between adjuvanted H1N1/09 vaccination and PE and/or IUGR.