The fundal height is the distance between the pubic bone and the top of the uterus. It gives clues as to a developing fetus’s position and growth rate.

At 28 weeks, the fundal height is usually around 28 centimeters.

The main purpose of measuring fundal height is to check whether the fetus is growing as expected. This article explores this measurement in more detail, including what it can tell someone about their pregnancy.

A pregnant female's abdomen being measured with a tape measure.Share on Pinterest
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Measuring fundal height helps healthcare professionals screen for any irregularities in fetal growth.

The first measurement typically takes place after 24 weeks of gestation. This simple, affordable method can help healthcare professionals tell whether further investigation into fetal growth is necessary.

It can be a useful way of checking fetal growth in areas where access to medical equipment is difficult. Also, a doctor may gain a more accurate understanding by considering this measurement alongside an ultrasound scan.

A healthcare professional measures the distance from the pubic bone to the top of the uterus.

First, they may ask the person to empty their bladder, as having a full bladder may alter the measurement.

Next, they locate the upper border of the pubic symphysis, a joint between the left and right parts of the bottom section of the pubic bone. Then, they locate the uterine fundus, the uppermost, rounded part of the uterus.

They then use a tape measure to check the distance between these areas and record the measurement in centimeters (cm).

The first fundal measurement typically takes place after 24 weeks. The care team then takes more measurements as the pregnancy progresses and compares these with the average for a healthy pregnancy.

Fundal height generally corresponds with weeks of pregnancy, give or take 2 cm. For example, at 28 weeks, a person’s fundal height is usually within 2 cm of 28 cm.

Fundal height measurements can give information about the position and growth of a fetus.

Learn about the stages of fetal growth.

Various factors can lead to inaccurate fundal height measurements. For example, if a pregnant person has obesity, their fundal height may be greater than that of the average for the gestation week. This can mean that the measurement is a less accurate way of checking fetal growth.

On the whole, fundal height is an accurate tool. The American College of Obstetricians and Gynecologists, for example, recommends it alongside ultrasound scans.

Here are some frequently asked questions about fundal height.

What if fundal height is low?

There are several reasons for a low fundal height. It indicates that the fetus is small, considering its gestational age. This may be no cause for concern.

However, in other cases, it may suggest that there is intrauterine growth restriction. Without effective treatment, this can cause mortality for the fetus and the pregnant person.

Another possible cause of a low fundal height is oligohydramnios. This refers to having too little amniotic fluid around the fetus. Without treatment, this can cause complications.

What if fundal height is high?

This can show that the fetus is growing too fast, which can carry risks for the fetus and the pregnant person.

A high fundal height can also stem from polyhydramnios, which means having too much amniotic fluid. This is not directly dangerous, but it can cause complications that put the pregnancy at risk.

However, it is important to note that a high fundal height may simply indicate that a person has multiple pregnancies, such as twins or triplets.

What if fundal height is ‘behind schedule’?

This can indicate that the fetus naturally grows at a rate that is slower than average.

But it can also indicate that a complication is restricting fetal growth. A healthcare professional can then check for complications with an ultrasound scan.

A healthcare professional uses a tape measure to check the distance between the pelvic bone and the top of the uterus. This measurement, in cm, is the fundal height. It can give information about the growth of a fetus.

The measurement typically aligns with the number of weeks that the person has been pregnant, give or take 2 cm.

Having a low or high reading may be no cause for concern, or it may point to a pregnancy complication. To assess this, a doctor uses other tools, such as an ultrasound scan.