Department of Obstetrics and Gynaecology, Children's and Women's Health Centre, University of British Columbia, Vancouver, BC, Canada. slisonkova@cfri.ca
We compared perinatal mortality, preterm birth (35-year-old women. Further, we examined whether older maternal age effects were modified by parity or otherwise affected by chorionicity.
We carried out a population-based retrospective cohort study including all twin births in British Columbia (BC), Canada, from 1999 to 2003. The BC perinatal database registry was used to obtain clinical, behavioral and demographic data. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated using generalized estimating equation models.
Overall, twins of older women were more likely to be born preterm (