Fetal ear development

During the fifth month, a baby’s outer ears are almost fully developed. Ear formation starts from a few small lumps during the second month. Let’s go and take a look.

Here we see a baby during the fifth week of development. Those small bulges are called branchial arches. During month three, the branchial arches formed the lower face and neck. The ears developed from them, too, between those two branchial arches. Let’s take a closer look. In the fifth week, they were smooth. But a week after that, tiny bumps called auricular hillocks formed on each branchial arch. Now here’s the fascinating part. Watch what happens from the sixth week until the end of the fifth month...As you can see, the auricular hillocks grew and joined together to form the baby’s outer ears.

During the fifth month, the inner and middle part of the baby’s ears are also developing, but they won’t be completely finished until birth. And here’s what they’ll look like at that time.

Review Date: 8/23/2023

Reviewed By: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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