Fundal Height

What Fundal Height Measures

The fundus is the top of the uterus. As pregnancy progresses the uterus grows upward, so the distance from the pubic bone to the fundus is a rough proxy for how the pregnancy is growing.^[1] That's the whole idea: one tape, one number, no machine.

How It's Measured

A clinician runs a tape measure from the pubic symphysis up over the belly to the top of the uterus and records the distance in centimeters.^[1] UK guidance describes it as part of routine appointments in the later part of pregnancy, with measurements plotted on a growth chart against gestational age.^[3] The chart works because of a simple population fact: across thousands of healthy pregnancies, fundal height climbs almost in a straight line as the weeks pass.^[2]

Why People Track It

Fundal height is one of the few pregnancy measurements that arrives as a plain number at nearly every visit, which makes it easy to record. Logging each measurement with its date builds your own curve across the pregnancy, the same shape your clinician plots on their chart. The interpretation stays with them. What you keep is the record.

For how pregnancy tracking apps handle appointment data like this, see our guide to the best pregnancy tracking apps.

How Go Go Gaia Tracks It

Go Go Gaia has a fundal height log built in. After a visit, you enter the measurement in one tap and the app charts it on your pregnancy timeline, next to fetal heart rate and the rest of your record. Months of appointments become one curve instead of scattered notes.

What the Research Shows

The INTERGROWTH-21st project measured fundal height serially in 4,321 healthy pregnancies across eight countries and found the measurements "increased almost linearly with gestational age," which is what makes week-based reference curves possible.^[2]

The evidence on how well it works as a screen is thinner than its ubiquity suggests. A Cochrane review found just one trial, of 1,639 women, comparing tape measurement with palpation by hand, and concluded there wasn't enough evidence to say whether fundal height measurement detects growth problems.^[1] The UK's guideline committee reviewed the same question in 2021, noted how little accuracy data exists, and kept the measurement in routine care anyway because it's quick, cheap, and essentially without downsides.^[3]

The measurement itself is also noisy. A study of inter-observer variation found that while summary statistics looked reassuring, the limits of agreement between different examiners were very wide, and different observers couldn't reliably agree on which measurements were small.^[4] Two clinicians measuring the same person on the same day can land on different numbers. That's a property of the tape, not of the pregnancy.

Related Terms

Frequently Asked Questions

Educational information based on published sources. Not medical advice. For personal concerns, please consult your doctor.

How is fundal height measured?

A clinician runs a tape measure from the pubic bone (the pubic symphysis) up to the top of the uterus (the fundus) and records the distance in centimeters. It takes seconds, needs no equipment beyond the tape, and is a routine part of prenatal appointments in the second half of pregnancy.

Why do fundal height measurements vary between appointments?

Partly because the pregnancy is growing, and partly because the measurement itself is imprecise. A study of inter-observer variation found the limits of agreement between different examiners were very wide, meaning two clinicians measuring the same person can land on noticeably different numbers. That's a known property of the tool, and it's one reason clinicians look at the trend rather than any single value.

What is fundal height used for?

Clinicians use it as a quick, low-cost screen for how the uterus is growing, plotted against gestational age. The evidence behind it is thin. A Cochrane review found only one trial and concluded there wasn't enough evidence to say how well it detects growth problems, and UK guidance keeps it in routine care largely because it's easy, cheap, and harmless.