Overview
Babies can be small because of the placenta, high blood pressure, smoking, infections, or simply small parents.
Doctors watch growth and blood flow with ultrasounds and may plan an earlier delivery.
Symptoms
Common signs:
- Baby measuring small
Less common
- Baby measures small
Look up a symptom: Pregnant or recently gave birth
When to get medical care
Call 911Heavy bleeding, severe belly pain, a seizure, or fluid that's green or brown with fewer baby movements: call 911 or go to labor and delivery.
Get care todayFewer baby movements.
See a doctor soonGrowth concerns.
Causes
Placenta, smoking, genes.
Does it spread or run in families?
- It isn't contagious. You can't catch it from someone else.
Who is more likely to get it
- Smoking
- High blood pressure
Diagnosis
Ultrasound measures growth.
Tests
Tests, if needed:
- Ultrasound:
Treatment
Follow the plan.
Self-care
- Count kicks in pregnancy
- Feed often after birth
- Don't smoke
- Keep all ultrasound visits
Prevention
To lower your risk or prevent problems:
- Don't smoke
- Don't smoke or drink alcohol
- Keep prenatal visits
Which doctor treats this
- Start with your child's pediatrician.
- They may send you to a pediatric specialist: an OB-GYN or a maternal-fetal medicine doctor.
Children, pregnancy, and older adults
- After birth: Baby's blood sugar and temperature are checked.
For caregivers
- Learn the warning signs and when to call the doctor or 911.
- Keep a list of your child's medicines, doses, and doctors on your phone.
- Tell teachers, coaches, and sitters what to watch for and what to do.
- Take breaks and ask for help. Caregivers need care too.
Outlook
Many catch up.
Many small babies catch up in growth.
Getting ready for your visit
Bring a list of your symptoms and medicines.
Questions to ask
- How often will we check the baby?
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Sources
Last updated 2026-11-12.