--- title: "Third Trimester Fetal Development at Sutter Health" description: "Explore your baby’s development during months 7 to 9 of pregnancy, including key growth milestones and exciting changes as birth approaches." url: "https://www.sutterhealth.org/health/third-trimester-fetal-development" --- 1. [Home](https://www.sutterhealth.org/) / 2. [Health and wellness](https://www.sutterhealth.org/health) / 3. Third Trimester Fetal Development # Fetal Development: Third Trimester  Learn how babies grow during weeks 28-40 of pregnancy. * * * August 18, 2025Medically reviewed by [Carrie C. Yiakis, M.D.](https://www.sutterhealth.org/find-provider/dr-carrie-c-yiakis-1046233432) In the final trimester, your baby is busy growing and getting ready for life outside the womb. Each month brings new changes and milestones, bringing you closer to meeting your little one. Here’s a quick look at what’s happening in months 7 through 9. (Sizes and weights are approximate.) ![fetal-development-third-trimester-1664a](https://edge.sitecorecloud.io/sutterhealt962c-sutterhealt8fce-production57cc-4860/media/Project/SutterHealth/SutterHealth/Images/health-topics/birth-babies/fetal-development-third-trimester-1664a.jpg) ## Month 7 By the end of month 7: - Baby is 14 to 16 inches long - Fat layers are forming - If born at this time, the baby will be considered premature and require special care - Organs are maturing - Skin is still wrinkled and red - Taste buds have developed - Weight is about 2½ to 3½ pounds  ## Month 8 By the end of month 8: - Baby is 16½ to 18 inches long - Fingernails now extend beyond fingertips - Kidneys are mature - Most body organs are now developed, except for the lungs - Movements or “kicks” are strong enough to be visible from the outside - Overall growth is rapid this month - Skin is less wrinkled - Tremendous brain growth occurs at this time - Weight is about 4 to 6 pounds  ## Month 9 By the end of month 9: - Baby is 19 to 20 inches long - Baby is now fully developed and can survive outside the mother’s body - Skin is pink and smooth - The baby settles down lower in the abdomen to prepare for birth and may seem less active - The lungs are mature - Weight is about 7 to 7½ pounds  This final stretch of pregnancy is filled with anticipation as your baby gets ready for their big debut. Each kick and hiccup brings you one step closer to holding them in your arms.  ## Explore related topics [Pregnancy](https://www.sutterhealth.org/health/articles?facets=%5B%7B%22i%22%3A%22c_healthTopics.name%22%2C%22v%22%3A%5B%22Pregnancy%22%5D%7D%2C%7B%22i%22%3A%22builtin.entityType%22%2C%22v%22%3A%5B%22Sutter+Health+Page%22%5D%7D%5D&limit=10&verticalKey=health-and-wellness)[Fetal Development](https://www.sutterhealth.org/health/articles?facets=%5B%7B%22i%22%3A%22c_healthTopics.name%22%2C%22v%22%3A%5B%22Fetal+Development%22%5D%7D%2C%7B%22i%22%3A%22builtin.entityType%22%2C%22v%22%3A%5B%22Sutter+Health+Page%22%5D%7D%5D&limit=10&verticalKey=health-and-wellness)[Third Trimester](https://www.sutterhealth.org/health/articles?facets=%5B%7B%22i%22%3A%22c_healthTopics.name%22%2C%22v%22%3A%5B%22Third+Trimester%22%5D%7D%2C%7B%22i%22%3A%22builtin.entityType%22%2C%22v%22%3A%5B%22Sutter+Health+Page%22%5D%7D%5D&limit=10&verticalKey=health-and-wellness) ## Support at Every Step From conception to delivery and after, our [pregnancy and childbirth](https://www.sutterhealth.org/services/pregnancy-and-childbirth) providers put you first. [Book an Appointment](https://www.sutterhealth.org/find-provider-results?facets=%5B%7B%22i%22%3A%22c_providerSpecialties.specialty.name%22%2C%22v%22%3A%5B%22Infertility%22%2C%22Nurse+Midwife%22%2C%22Obstetrics+and+Gynecology%22%2C%22Reproductive+Endocrinology%22%5D%7D%5D&limit=10&verticalKey=healthcare_professionals) ## Meet our care team ![Carrie C. Yiakis, M.D.](http://a.mktgcdn.com/p/GYp7jSrCOf82lVHju3PkcCDSIlQibu4M32TkVOMEN1M/480x480.jpg) [Carrie C. Yiakis, M.D.](https://www.sutterhealth.org/find-provider/dr-carrie-c-yiakis-1046233432) Obstetrics and Gynecology ```json {"@context":"https://schema.org","@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org","logo":"https://www.sutterhealth.org/static/images/sutter-health-logo.svg","address":{"@type":"PostalAddress","streetAddress":"2200 River Plaza Drive","addressLocality":"Sacramento","addressRegion":"CA","postalCode":"95833","addressCountry":"US"},"areaServed":{"@type":"AdministrativeArea","name":"California"},"sameAs":["https://www.facebook.com/SutterHealth","https://www.instagram.com/sutterhealth/","https://x.com/SutterHealth","https://www.youtube.com/sutterhealth","https://www.linkedin.com/company/sutter-health","https://en.wikipedia.org/wiki/Sutter_Health"]} ``` ```json {"@context":"https://schema.org","@type":"WebPage","name":"Third Trimester Fetal Development at Sutter Health","description":"Explore your baby’s development during months 7 to 9 of pregnancy, including key growth milestones and exciting changes as birth approaches.","url":"https://www.sutterhealth.org/health/third-trimester-fetal-development","breadcrumb":{"@id":"https://www.sutterhealth.org/health/third-trimester-fetal-development#breadcrumblist"}} ``` ```json {"@context":"https://schema.org","headline":"Fetal Development: Third Trimester ","alternativeHeadline":"Third Trimester Fetal Development at Sutter Health","description":"Explore your baby’s development during months 7 to 9 of pregnancy, including key growth milestones and exciting changes as birth approaches.","datePublished":"2025-08-18T00:00:00Z","dateModified":"2026-10-23T16:03:49Z","publisher":{"@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org"},"image":{"@type":"ImageObject","url":"https://edge.sitecorecloud.io/sutterhealt962c-sutterhealt8fce-production57cc-4860/media/Project/SutterHealth/SutterHealth/Images/health-topics/birth-babies/fetal-development-third-trimester-1664a.jpg?h=1109&iar=0&w=1664","width":"1664","height":"1109","caption":"fetal-development-third-trimester-1664a"},"@type":"MedicalWebPage","breadcrumb":{"@id":"https://www.sutterhealth.org/health/third-trimester-fetal-development#breadcrumblist"},"reviewedBy":[{"@context":"https://schema.org","@type":"Person","name":"Carrie C. 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