Skip to main navigation Skip to main content Skip to footer For Medicare For Providers For Brokers For Employers Español For Individuals & Families: For Individuals & Families
Shop for Plans

Shop for Plans
Shop for your own coverage
Medical Dental Other Supplemental
Plans through your employer

Learn about the medical, dental, pharmacy, behavioral, and voluntary benefits your employer may offer.

Explore coverage through work
Learn
How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics
Looking for Medicare coverage?
Shop for Medicare plans
Member Guide
Find a Doctor
Medical Dental Other Supplemental Explore coverage through work How to Buy Health Insurance Types of Dental Insurance Open Enrollment vs. Special Enrollment See all topics Shop for Medicare plans Member Guide Find a Doctor Log in to myCigna
Home Knowledge Center Wellness Library Physical Development, Ages 1 to 12 Months

Physical Development, Ages 1 to 12 Months

Overview

Babies grow quickly during the first year of life. Weight, length, and head circumference measurements are plotted on growth charts to monitor your baby's growth over time. Most babies:

  • Grow about 3 in. (7.5 cm) to 4 in. (11 cm) in length by 4 months of age. Growth may slow slightly between 4 and 7 months of age. But by 12 months of age most babies have grown a total of about 10 in. (25 cm) in length since birth and are about 28 in. (71 cm) to 32 in. (81 cm) long.
  • Gain an average of about 4 lb (2 kg) to 6 lb (2.7 kg) by 4 months of age. Birth weight usually doubles by 6 months of age. It triples sometime between 9 and 12 months of age.

The soft spots, or fontanelles, on top of a baby's skull start to close at 6 months.

When your baby is about 6 months old, teething may start. Teeth may not yet break through the gums at this age. But your baby may drool, chew on objects or hands, and act fussy from the pressure of new teeth coming in.

Keep in mind that each baby is different. Growth patterns can change between routine well-child checkups. If you have concerns, talk to your doctor about the many things that can affect your baby's growth.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

To learn more about Ignite Healthwise, LLC, visit webmdignite.com.

© 2024-2025 Ignite Healthwise, LLC.

Related Links

Feeding Your Infant Teething Growth and Development, Ages 1 to 12 Months Failure to Thrive

<cipublic-spinner variant="large"><span>Loading…</span></cipublic-spinner>

Page Footer

I want to...

Get an ID card File a claim View my claims and EOBs Check coverage under my plan See prescription drug list Find an in-network doctor, dentist, or facility Find a form Find 1095-B tax form information View the Cigna Glossary Contact Cigna

Audiences

Individuals and Families Medicare Employers Brokers Providers

Secure Member Sites

myCigna member portal Health Care Provider portal Cigna for Employers Client Resource Portal Cigna for Brokers

The Cigna Group Information

About Cigna Healthcare Company Profile Careers Newsroom Investors Suppliers The Cigna Group Third Party Administrators International Evernorth

 Cigna. All rights reserved.

Privacy Legal Product Disclosures Cigna Company Names Customer Rights Accessibility Non-Discrimination Notice Language Assistance [PDF] Report Fraud Sitemap Cookie Settings

Disclaimer

Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., Cigna HealthCare of Georgia, Inc., Cigna HealthCare of North Carolina, Inc., Cigna HealthCare of South Carolina, Inc., and Cigna HealthCare of Texas, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see a listing of the legal entities that insure or administer group HMO, dental HMO, and other products or services in your state). Accidental Injury, Critical Illness, and Hospital Care plans or insurance policies are distributed exclusively by or through operating subsidiaries of Cigna Corporation, are administered by Cigna Health and Life Insurance Company, and are insured by either (i) Cigna Health and Life Insurance Company (Bloomfield, CT); (ii) Life Insurance Company of North America (“LINA”) (Philadelphia, PA); or (iii) New York Life Group Insurance Company of NY (“NYLGICNY”) (New York, NY), formerly known as Cigna Life Insurance Company of New York. The Cigna name, logo, and other Cigna marks are owned by Cigna Intellectual Property, Inc. LINA and NYLGICNY are not affiliates of Cigna.

All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.

Selecting these links will take you away from Cigna.com to another website, which may be a non-Cigna website. Cigna may not control the content or links of non-Cigna websites. Details