If in the first trimester the rate of abdominal enlargement is determined only by individual characteristics, then as pregnancy progresses, a deviation in the size of the abdominal circumference from the norm may signal complications or an incorrectly set period.
Starting around the 12th week, your doctor will measure the height of the fundus of the uterus (the distance from the symphysis pubis to the edge of the uterus) and abdominal circumference at each appointment. It is believed that after the 12th week the belly should increase by an average of 1 cm per week. Thus, a woman of average build will have an abdominal circumference of 100-110 cm by the end of pregnancy.
There are special tables that obstetricians-gynecologists use to determine whether your abdominal circumference is normal, but they cannot give an accurate picture; it all depends on your initial waist circumference and the characteristics of pregnancy. That is why doctors pay more attention to the dynamics of abdominal enlargement.
Let’s say right away that how the belly looks and grows during pregnancy depends on many reasons: the woman’s physique, the structure of the pelvis, the condition of the muscles, the growth of the uterus and child, the amount of amniotic fluid. Therefore, for some, the belly grows faster, for others slower, for some mothers it is large, for others it can be almost invisible. But still, there are some general patterns in the growth and size of the abdomen during pregnancy.