<prompt> Best time to do USG in pregnancy, if it is to be done once in entire pregnancy, would be: March 20116-8 weeks10-12 weeks18-22 weeks34-36 weeks  <response>: Ans. C: 18-22 weeks Routine USG at 18-22 weeks gestation has the following effects 1 reduces the incidence of post-term pregnancy 39 and rates of induction of labour for post-term pregnancy, 2 increases early detection of multiple pregnancy 92, 3 increases early detection of major fetal anomalies when termination is possible, 4 no significant differences in the clinical outcomes such as perinatal moality and 5 reduces neonatal admission to special care baby unit 14 