As you advance to the later stages of pregnancy, you will find that your doctor measures your growing belly vertically with the help of a measuring tape. What your doctor is measuring is called Fundal Height, which is the measure of the size of uterus. Measured from the uterus of the expecting mother to the top of her pubic bone, fundal height is useful in evaluating fetal growth and development. Fundal height is measured in centimeters and starting from the second trimester fundal height in centimeters must match the gestational age of the fetus in terms of the number of weeks.
Sometimes fundal height measures 2-3 centimeters less than the gestational age and this variation is considered normal, not indicative of any major problem with the fetus.
Though an ultrasound is the most accurate method to determine fetal growth and development, fundal height can be a useful indicator too. Since ultrasounds cannot be performed at every pre-natal visit, many doctors use fundal height to monitor the proper growth of the fetus.
A rapidly increasing fundal height varying more than 2-3 centimeters from the gestation age in weeks is a cause of concern. This may be due to a very rapidly growing fetus growth often attributed to gestational diabetes in the mother.
A rapidly increasing fundal height may also be indicative of excess amniotic fluid, which signals genetic or anatomical problems with the baby.
Uterine fibroids which cause pre-term labor and lead to miscarriages can also lead to higher than usual fundal height measurements. Your doctor will order ultrasound or other tests to determine the cause of increased fundal height measurements.
Similarly, if the fundal height is much smaller than the gestational age of the fetus, this too can signal problems with the baby or the pregnancy. Very little amount of amniotic fluid can cause shorter than normal fundal height measurements.
This problem may indicate a problem with the baby’s development and growth. The baby in “breech” position, sitting high up in the uterus can also lead to very small fundal height measurements.
Though fundal height is not the most accurate indicator of fetal growth, it does give a high-level view of the health of the baby and the pregnancy.