- 1st trimesteric pregnancy loss with gestational age 12 weeks or less (diagnosis was confirmed using transvaginal ultrasound according to the following criteria: Crown-rump length {CRL} of 7 mm or more and no heartbeat, Mean sac diameter {MSD} of 25 mm or more and no embryo, absence of embryo with heartbeat 2 wk or more after a scan that showed a gestational sac without a yolk sac and absence of embryo with heartbeat 11 days or more after a scan that showed a gestational sac with a yolk sac)