The influence of maternal smoking and LBW incidence is studied. Detailed smoking history is taken at first AN visit and smoking history and bih weight were studied later. The type of study is-
prospective coho studies is one which the outcome has not yet occurred at the time the investigation begins.most prospective studies begin in the present and continue into future. ref:park&;s textbook,ed 22,pg no 73
Retrospective coho study
Cross sectinal study
Clinical trial
Prospective coho study
Epidemiology