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The accuracy of ultrasound scans for measuring baby's size in pregnancy: How reliable are they?

In pregnancy, the anticipation and excitement of meeting your little one often comes with a lot of questions. Recently, the labels of 'big' and 'small' babies have been echoing in the conversations with my clients and expecting parents. However, the truth is, determining the actual size of your baby is a mystery until they make their grand entrance into the world!


a woman having an ultrasound scan in pregnancy

Ultrasound scans can be used for assessing fetal development including size, and are promoted to be accurate about 70% of the time. Not perfect stats but sounds reassuring, right? Well, here's the catch - there's a 15% discrepancy in either direction! So, imagine expecting that perfect 8lb bundle of joy, and it turns out they could weigh anywhere between 6lb 8oz and 9lb 2oz and still be classed as "accurate"


Understanding this information on ultrasound accuracy can be a game-changer when it comes to the decisions you make during pregnancy. Is your baby's size and weight tracking as expected? Are there other risk factors to consider? It might just be your baby's unique disposition to be a certain size!


Being armed with this knowledge empowers you to make informed decisions. Take a moment to reflect on whether your baby's size aligns with expectations and consider any potential risk factors.


This insight not only gives you a clearer picture but also allows you to approach your pregnancy journey with a clear understanding and knowledge to go forward.


As you navigate the twists and turns of pregnancy, remember that the joy of meeting your baby is an experience like no other. Embrace the uncertainty, stay informed, and make decisions that align with the unique journey you and your little one are on.



Holly - Doula and hypnobirthing teachers signature

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