Understanding Growth Scans in the Third Trimester: Expert Insights

As a perinatal educator and birth professional based in Bristol and Somerset, I understand the concerns that come with growth scans in the third trimester. It’s important to recognize that while these scans provide helpful insights, they have a significant margin of error. Fetal weight estimates can vary by as much as 300g to 550g, making them unreliable in determining the size of your baby at birth.

Baby Size Variations:
Every pregnancy is unique, and your body is perfectly capable of growing babies of all shapes and sizes. In the absence of complications such as uncontrolled gestational diabetes, your baby’s size will not impact your birth experience as much as you might think. Growth scans simply cannot predict how your baby will enter the world.

The Limitations of Growth Scans:
Though helpful for monitoring health concerns, growth scans are not definitive when it comes to determining your baby’s birth weight. The clinical evidence shows that these scans are often inaccurate, with some studies indicating they can be off by as much as 1.2 pounds. The result? A lot of unnecessary worry for expectant families.

As a professional working closely with pregnant families, I always encourage my clients to trust their bodies and to remember that your baby's growth is natural and part of your unique journey. Your body knows what to do.

Listen to Real Big Baby Birth Stories:
If you want to hear empowering real-life stories about big baby births, We highly recommend checking out the Talk Birthy With Us podcast. We discuss birth stories, including experiences with big babies, to show that no matter your baby’s size, you are capable of an amazing birth experience.

Listen here: Talk Birthy With Us

For families in Bristol, Somerset, and beyond, remember: your body, your baby, and your birth experience are unique—and no scan can change that.