Materials and Methods
This retrospective cohort study was conducted
by reviewing medical records of pregnant women who
presented for antenatal care and delivered in our
institution between December 2009 and August 2012.
Eligibility criteria were term, singleton pregnant women
who had their first antenatal booking at gestational age
(GA) less than or equal to 13 weeks. These women
must have certain GA by their last menstrual period or
by early ultrasound at an initial visit.