Seven Common Reasons for Large Fundal Height Measurements

Fundal height is a measurement in centimeters from the top of the pelvic bone to the top of the uterus. Fundal height usually corresponds with the gestational age of a pregnant woman’s baby in weeks. For example, if a woman is 25 weeks pregnant a doctor would expect her fundal height to be 25 centimeters, or within 2 to 3 centimeters above or below that number. Sometimes a pregnant woman’s fundal height can run too large. This may or may not indicate a problem with the pregnancy. Here are seven common reasons why a pregnant woman’s fundal height may run large and whether or not it poses a risk to her developing baby:

1) Your Dates Are Off
Sometimes a woman miscalculates her last menstrual period and she may be further along than she thinks she is. A woman who miscalculates her dates may be six months pregnant rather than four. In this case, she may measure large for her miscalculated date. An ultrasound is the most accurate way to confirm how far along a pregnancy is.

2) Previous Pregnancies
Have you ever heard the saying that you show sooner with your second? This is true because the abdominal muscles were stretched from your previous pregnancy and may not “hide” your growing belly as well as the first time around. This can cause a woman to measure on the larger side.

3) Your Baby Is Large but Healthy
Many times a high fundal height just means your baby is large with no complications. These days it is not uncommon for babies to be born weighing more than 9 pounds. Consider your family history and ethnicity. Do large babies run in your family?

4) Breech Baby
Four in 100 babies are breech, meaning they are positioned head-up, during late pregnancy. A breeched position causes higher than normal fundal height. Your baby may turn head down on her own or may require a doctor to attempt to flip her, but babies that fail to flip are usually delivered by a c-section.

5) Uterine Fibroids
Uterine fibroids are generally harmless fibrous tumors that grow on the uterus and can cause a false high fundal height measurement.

6) Too Much Amniotic Fluid
Polyhydramnios is a pregnancy complication meaning you have a higher than normal amniotic fluid level. Polyhydramnios can be caused by maternal diabetes, genetic or fetal abnormalities, or fetal anemia. If your doctors confirm you have too much amniotic fluid, you may need to take some extra tests and precautions during labor.

7) Gestational Diabetes
Gestational diabetes is a condition relating to high blood sugar during pregnancy. A woman may or may not have had diabetes prior to becoming pregnant. All women in the U.S. are tested for gestational diabetes at some point in their pregnancy, typically around the beginning of their third trimester. If you find out you have gestational diabetes, your baby is likely to be on the larger than average size, and in some cases, it will require a c-section to deliver due to their size.

These are seven common reasons explaining your high fundal height measurements. Remember it is normal for fundal height to jump up and down from one appointment to the next. Your doctor may need to see your measurements run consistently high before he takes further action to determine the cause. Relax, because most of the time a higher than normal fundal height measurement is usually harmless for both mother and baby.