In the first trimester, which statement best describes the concept of maximum fetal size?

• A. There is a fixed maximum crown-rump length for dating.
• B. The maximum size is fixed at a particular CRL (for example, 84 mm).
• C. Growth continues with gestational age; there is no fixed maximum.
• D. Fetal size is capped at 60 mm CRL in the first trimester.

Answer: (C)

In the first trimester, fetal growth progresses with gestational age and there isn’t a fixed cap on size. Crown-rump length (CRL) is used to date the pregnancy, and while there’s a typical range for each week, individual fetuses vary in size. Because growth continues as the pregnancy advances, there is no universal maximum CRL in the first trimester. Values like 84 mm or 60 mm are approximate points associated with certain gestational ages, not hard limits, and applying a single cap would ignore normal variability.