Pregnancy Week By Week. With rare exception, if a first-trimester ultrasound examination was performed, especially one consistent with LMP dating, gestational age should not be adjusted based on a second-trimester ultrasound examination.
Your baby's growth can slow down and then have spurts. Which in the grand scheme of things means nothing. Accordingly, in creating recommendations and the associated summary table, single-point cutoffs were chosen based on expert review. Some of the information in this article disagrees with everything we have studied so far regarding dating pregnancies and ultrasound accuracy. You don't necessarily conceive on the day you have sex.