The effect of cigarette smoking on first‐trimester crown–rump length

Objectives: Does cigarette smoking impact the embryonic growth rate in the first trimester? Methods: This is a retrospective multicentre observational study of 2912 pregnancies. Women who presented to the early pregnancy and perinatal ultrasound units between 2010 and 2019 were included in the study. The data collected included the following: smoking status, the crown-rump length (CRL) of the pregnancy at the first ultrasound that showed an …