Author(s): ANDREASSEN, S., LAINE, K., EVENSON, K., VANGEN, S., SØRBYE, L., OWE, K., Institution: OSLO UNIVERSITY HOSPITAL, Country: NORWAY, Abstract-ID: 2003

INTRODUCTION:
Twin pregnancy has historically been a contraindication to physical activity. Despite higher incidences of preeclampsia and gestational hypertension (PE/GH) in twin pregnancies, women pregnant with twins have been excluded from studies on physical activity and PE/GH. Hence, we aimed to estimate the association of leisure-time physical activity (LTPA) on risk of PE/GH in women with twin pregnancy.
METHODS:
We included 1,760 women with twin pregnancies in the Norwegian Mother, Father and Child Cohort Study (1999-2008). Type and frequency of LTPA during pregnancy were prospectively self-reported using a validated questionnaire around gestational week 17. LTPA during the three months before pregnancy was recalled in the same questionnaire. The diagnosis of PE/GH was obtained from the Medical Birth Registry of Norway. We used multiple Poisson regression and restricted cubic splines to examine the associations between weekly frequencies of LTPA and the risk of PE/GH. We stratified the analyses by parity in a secondary analysis.
RESULTS:
The incidence of PE/GH was 14.3% (n=252), of which preeclampsia constituted 11.4% (n=201). Pre-pregnancy LTPA was not associated with risk of PE/GH in any analysis. The association between LTPA in gestational week 17 and PE/GH was U-shaped with the lowest risk observed among women reporting LTPA twice a week (relative risk (RR): 0.68, 95% confidence interval (CI): 0.48-0.98 [reference: no LTPA]). When stratified by parity, the association was strengthened among parous women during pregnancy, observing the lowest risk of PE/GH for women reporting LTPA three times per week (RR: 0.48, 95% CI: 0.26-0.87). This association attenuated among nulliparous women with the lowest risk observed at LTPA twice a week (RR: 0.85, 95% CI: 0.53-1.38).
CONCLUSION:
We are not aware of prior studies that examined the association between LTPA and PE/GH in twin pregnancies. The findings from this population-based study suggest that LTPA during twin pregnancy is safe and may lower the risk of PE/GH, particularly at low and moderate levels. Replication in other settings and study populations is warranted to avoid unnecessary activity restriction and develop evidence-based recommendations for physical activity in twin pregnancies.