Fundal height is generally defined as the distance from the pubic bone to the top of the uterus measured in centimeters. After 20 weeks of pregnancy, your fundal height measurement often matches the number of weeks you've been pregnant. For example, if you're 27 weeks pregnant, your health care provider would expect your fundal height to be about 27 centimeters.
A fundal height measurement might be less accurate, however, if you:
- Are obese
- Have a history of fibroids
- Are carrying twins or other multiples
A fundal height that measures smaller or larger than expected — or increases more or less quickly than expected — could indicate conditions such as:
- Slow fetal growth (intrauterine growth restriction)
- A significantly larger than average baby (fetal macrosomia)
- Too little amniotic fluid (oligohydramnios)
- Too much amniotic fluid (polyhydramnios)
Depending on the circumstances, your health care provider might recommend an ultrasound to determine what's causing the unusual measurements or more closely monitor your pregnancy.
But fundal height is only a tool for gauging fetal growth — it's not an exact science. Typically, fundal height measurements offer reassurance of a baby's steady growth. If you're concerned about your fundal height measurements, ask your health care provider for details.