Not yet recruitingNAINTERVENTIONAL

Ultrasound Estimation of Fetal Macrosomia at Term: Diagnostic Accuracy Within 24 Hours of Delivery

This study aims to improve how we estimate a baby's size before birth, especially if they are thought to be larger than average, a condition called macrosomia. Doctors use ultrasound scans to estimate a baby's weight, which helps them decide on the safest way for the baby to be born, such as whether to suggest inducing labour or having a C-section. However, these estimates aren't always completely accurate. We want to find out if doing an ultrasound scan very close to the time of birth, within 24 hours, gives a more precise weight estimate. The idea is that a more accurate estimate could help avoid unnecessary procedures for both mum and baby, making sure they get the best care.

At a glance

Status

Not yet recruiting

Phase

Sponsor

Centre Hospitalier Henri Duffaut - Avignon

Enrolment target

285

Start

01 Mar 2026

Estimated completion

01 Sep 2028

Macrosomia Fetal Weight

What is this study about?

When you're expecting a baby, regular ultrasound scans are a really important way for doctors and midwives to check on your baby's growth and wellbeing. In the UK, these scans help keep an eye on how your baby is developing. One of the things they measure is your baby's estimated weight. This helps healthcare professionals see if your baby is growing as expected or if there might be any concerns.

Sometimes, a baby might be growing larger than average, which doctors call 'macrosomia'. This means their birth weight is expected to be 4000g (about 8 pounds 13 ounces) or more. If a baby is estimated to be very large, there can be a slightly higher chance of certain difficulties during birth for both mum and baby. Doctors usually use a specific formula, based on measurements from the ultrasound scan, to estimate your baby's weight. This estimate has a small margin of error, but it's usually good enough to help them make important decisions, like whether to suggest inducing labour (starting labour artificially) or planning a C-section (a surgical birth).

This study wants to see if we can make these weight estimates even more precise. Currently, baby weight is often estimatedweeks before birth. But babies continue to grow, and their growth rate can change. Researchers are wondering if doing an ultrasound scan much closer to the birth – within 24 hours – would give a more accurate picture of the baby's actual birth weight. If we can get a better estimate, it could help doctors make more informed choices, potentially reducing the need for interventions that might not be necessary, and ultimately leading to better outcomes for both mum and baby.

Key takeaways

The study explores if ultrasounds closer to birth give more accurate baby weight estimates.
Better weight estimates could help doctors make more informed decisions about delivery.
It aims to reduce unnecessary medical procedures for mums and babies.
Participation involves an ultrasound scan potentially within 24 hours of birth.
The study focuses on babies suspected of being larger than average (macrosomia).

Who may be eligible?

To be part of this study, you would need to be at least 18 years old and pregnant with one baby. Your healthcare team would have already had an ultrasound where your baby was thought to be larger than average (macrosomia). This would have happened during your third trimester, usually between 32 and 34 weeks of pregnancy.

You would also need to be coming in for a follow-up ultrasound around 36 weeks of pregnancy specifically because of this suspected larger baby size.

There are some reasons why you wouldn't be able to join. For example, if your baby's weight was estimated at 36 weeks outside of the hospital, or if there's any doubt about how far along you are in your pregnancy. If you're pregnant with twins or more, or if your baby has any known significant health problems, you also wouldn't be able to take part.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you 18 years old or older?
Are you pregnant with only one baby?
Has an earlier ultrasound suggested your baby might be larger than average (macrosomia)?
Are you having a follow-up ultrasound around 36 weeks of pregnancy for this reason?
Is your pregnancy overall healthy, without known serious problems with the baby?

Answer every question to see your result.

What does participation involve?

Information about what taking part involves is not fully detailed in the provided brief summary. However, based on the study's aim, it is likely that participation would involve receiving an ultrasound scan within 24 hours before your baby is born. This would be in addition to any routine scans you're already having. The study is comparing the accuracy of ultrasounds done at different times, so it would involve your healthcare team using the information from this close-to-delivery scan to see how well it predicts your baby's actual birth weight. There's no mention of new medications or extra visits beyond the ultrasounds. The total duration of your direct participation would likely be brief, focused around the time of the additional ultrasound and your baby's birth.

Potential risks and benefits

Taking part in this study may offer the benefit of potentially contributing to improved care for pregnant women and their babies in the future, by helping doctors make more accurate decisions based on better weight estimates. The primary intervention is an additional ultrasound scan, which is generally considered safe for both mother and baby. However, all medical procedures carry some very small, inherent risks, such as minor discomfort during the scan. You are always free to change your mind and withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Centre Hospitalier d'Avignon, Hôpital Henri Duffaut
Verified postcode
Avignon, France

Common questions

What is macrosomia?

Macrosomia means a baby is expected to be born larger than average, usually weighing 4000g (about 8 pounds 13 ounces) or more at birth.

Why is it important to know if a baby is macrosomic?

Knowing a baby's estimated size helps doctors plan for a safer birth. Very large babies can sometimes have a higher chance of certain difficulties during delivery for both mum and baby.

How do doctors estimate a baby's weight?

Doctors use measurements from ultrasound scans, like the size of the baby's head, tummy, and thigh bone, along with a special formula to estimate the baby's weight.

What does 'inducing labour' mean?

Inducing labour means doctors give you medicine or do procedures to start your labour artificially if it hasn't started on its own.

Will taking part in this study change my care?

The study aims to see if an ultrasound closer to birth gives a more accurate estimate. Any decisions about your care, like inducing labour or having a C-section, will still be made by your medical team in discussion with you, based on all the information available.

How to find out more

Marilyne Grinand, PhD

grinand.marilyne@ch-avignon.fr (+33)432759392 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.