Read on to learn about preterm birth, risk factors for preterm birth, and the important growth and development that occurs inside the womb.
In The News
- 2018 Premature Birth Report Cards March of Dimes
- Association Between Moderate and Late Preterm Birth and Neurodevelopment and Social-Emotional Development at Age 2 Years JAMA Pediatrics
- Births: Final Data for 2016 National Center for Health Statistics
What is Preterm Birth?Preterm birth is the delivery of a baby less than 37 weeks of pregnancy.2 The last weeks of pregnancy are critical to a baby's growth and development. Click below to understand the definitions week by week.
Click labels below to learn definitions.
Preterm birth is more common than you may think. In the United States, approximately 400,000 babies are born too early—or preterm—each year.6 More than 70% of all preterm births in the United States are late preterm births, a time in which important developments are still happening.7
Babies Continue Important Development,
Even in those Final Weeks of Pregnancy
Explore inside the womb through this interactive 360° video, and discover the growth you can’t see and what a baby has to gain by reaching full term.
Important developments occur during the last weeks of pregnancy. Babies need every week inside the womb, as the brain, lungs, and liver are among the last organs to develop. Regardless of birth weight, babies born early are also more likely to be re-hospitalized.8 That's why getting to full term is important.
Compared to term infants, late preterm infants were:8
It's important to know and understand the risk factors for preterm birth. Preterm birth is often unexpected. Some women may have an early delivery due to a medical situation, and sometimes one may have a greater chance of preterm birth due to known risk factors.1,2
Leading Risk Factors
- Prior preterm birth (unexpectedly delivered a baby before 37 weeks in the past)
- Pregnant with twins, triplets, or other multiples
- Problems with uterus or cervix
- African-American heritage
Other Risk Factors
- High blood pressure, stress, diabetes, or being overweight or underweight
- Smoking, drinking alcohol, or using drugs
- Short time between pregnancies
- Certain infections during pregnancy
Are You At Risk?
If you think you may be at risk for preterm birth, seek early prenatal care. Bring the risk factors checklist to your healthcare provider and talk with him or her about ways you can reduce your risk, including possible treatment options.
Signs & Symptoms of
Pregnant women should be familiar with the signs of preterm labor.12 If any signs or symptoms of preterm labor occur before a baby's due date, contact a healthcare provider as soon as possible.
Contractions, or tightening of the belly muscles, every ten minutes or less
Belly cramps with or without diarrhea
Low, dull backache
Cramps resembling menstrual cramps
Feeling of pressure in the pelvic area
A change in vaginal discharge
A Message from Moms to Moms
Hear how other moms learned about their preterm risk through these stories and video.
Learn More About Preterm Birth: Free Educational Resources
If you’re a healthcare provider, patient advocacy organization, insurance company, or someone interested in sharing educational materials, you can order free The Growth You Can’t See materials to help bring the importance of the last six weeks to life. Materials for order include a postcard to share with your patients to go inside the womb for a virtual reality experience, as well as an educational brochure and poster. You can also download a free digital toolkit of all the materials offered in the resource center below. Some materials are available in multiple languages.
Preterm Birth Resource Center
Health & Family Segment
Hear from a Maternal-Fetal Medicine specialist on preterm birth and its risk factors, and from a mom of two premature babies who also shares her experiences. At the time of video filming, Dr. Biggio was a consultant of AMAG Pharmaceuticals, Inc.