Two main reasons
If a pregnancy
has accurate dating from early sonogram
which is in agreement with lmp (last menstrual period
) and one sees a greater than 2 week lag in growth from the expected, it could signal iugr (intrauterine growth restriction).
This may be due to a placental problem or a genetic/developmental problem. Close monitoring of growth, amniotic fluid, and nst (nonstress test) is indicated.