# Fetal Growth Restriction ![](https://assets.bmc.org/transform/6416504b-77d1-442a-adaa-34943a4a85e9/8I0A4960?io=transform:fill,width:1000px&format=webp) Every pregnancy is unique, and babies grow at their own pace. Sometimes an unborn baby is smaller than expected or not growing at the normal rate. This is called **fetal growth restriction (FGR)** or **intrauterine growth restriction (IUGR)**. A baby has FGR when their estimated weight is **below the 10th percentile** for their **gestational age** (how many weeks they have developed, or the number of weeks of your pregnancy). This means that out of 10 babies at the same stage, your baby is estimated to weigh less than nine of them. FGR happens in about **one in every 10 pregnancies**. Most babies who measure small are born healthy, but FGR means your baby may need closer monitoring to make sure they are growing well and staying safe. ## What Causes Fetal Growth Restriction? Fetal growth restriction happens when your baby is having trouble getting enough oxygen and nutrients. The most common causes are problems with the placenta or umbilical cord. Other potential causes include: - Health conditions in the pregnant parent, like [high blood pressure](/bump-beyond/during-pregnancy/medical-care/high-blood-pressure-and-preeclampsia) or [diabetes](/bump-beyond/during-pregnancy/medical-care/gestational-diabetes-care) - Certain types of infection during pregnancy - Using [tobacco, alcohol, or drugs](https://www.bmc.org/bump-beyond/during-pregnancy/alcohol-cigarettes-and-street-drugs) during pregnancy - Genetic or chromosomal differences in the baby - Past pregnancy history (if you had a baby with growth restriction before, the risk can be higher in your later pregnancies) ## How Is Fetal Growth Restriction Diagnosed? During your prenatal visits, your provider checks how much weight you have gained overall, and also measures your belly (abdomen). A baby may have FGR if your belly measures smaller than the 10th percentile, even when your total weight is in the normal range. If your belly is smaller than expected, your provider may recommend an [ultrasound](/bump-beyond/during-pregnancy/medical-care/ultrasounds "Bump & Beyond: Ultrasounds | Boston Medical Center") to check your baby’s growth. Even with measuring and ultrasound, it can be hard to tell the difference between a baby who is small but healthy and a baby who is not growing well and needs closer care. About two out of every 10 babies who seem to have FGR on ultrasound are actually small but healthy and have no problems at birth. In addition to how large they look on the ultrasound, there are other signs that your baby might not be getting enough oxygen and nutrients to grow at the normal rate: - Changes in blood flow to the baby - [Lower levels of amniotic fluid](/bump-beyond/labor-and-birth/complications/what-oligohydramnios-low-amniotic-fluid) (the water around the baby) - Problems with your placenta ## What Can Happen if There Is Fetal Growth Restriction? **Content Warning: The next section talks about serious risks to babies.** ### Emergency C-Section During labor, babies with FGR may experience more stress and may be more likely to need a cesarean birth ([C-section](/bump-beyond/labor-and-birth/what-expect-during-labor/having-c-section)). ### Additional Medical Care Immediately after Birth After they are born, some babies with FGR need care in the neonatal intensive care unit (NICU), for problems like: - Low blood sugar - Infant jaundice - Infections - Trouble breathing **Be reassured that with close monitoring, most babies with FGR do well after birth.** ### Stillbirth Babies with fetal growth restriction (FGR) have a higher chance of **stillbirth** (being born dead), especially if they are very small or the placenta isn’t working well. The [risk of a stillbirth](https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2020/03/management-of-stillbirth) is also higher if you have high blood pressure, diabetes, or other health problems. Baby’s Size for Their Gestational AgeChance of a StillbirthNo fetal growth restriction (FGR)Six babies out of 1000 babies (0.64 percent)FGR: Baby in the 5th to 10th percentile15 babies out of 1000 babies (1.5 percent)FGR: Baby in the 3rd to 5th percentile25 babies out of 1000 babies (2.5 percent)FGR: Baby under the 3rd percentile50 babies out of 1000 babies (Five percent)## What Can I Do if My Baby Has Fetal Growth Restriction? ![](/sites/default/files/inline-images/Misc-Advocacy-2.png)If your baby is smaller than expected, your care team may recommend: - **More frequent checkups** to watch your baby’s health closely, including ultrasound imaging once or twice a week, to check: - Amniotic fluid levels (the water around the baby) - Baby’s growth and estimated weight - Baby’s heart rate - Blood flow - **Visits with specialists**, such as: - A doctor who specializes in high-risk pregnancies ([maternal–fetal medicine](/departments/obstetrics-and-gynecology/obstetrics/maternal-fetal-medicine "Department of Obstetrics & Gynecology: Division of Maternal–Fetal Medicine | Boston Medical Center")) - A [genetic counselor](/node/176736 "Genetic Services: Prenatal Genetics | Boston Medical Center"), if needed ## Delivering Your Baby Early **Most babies with growth restriction grow better after they are born than inside the womb.** Your care team may recommend that you [give birth before your due date](https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2020/03/management-of-stillbirth), either by [inducing labor](/node/177479 "Bump & Beyond: Everything You Need to Know about Inducing Labor | Boston Medical Center") or a planned [C-section](/node/177385 "Bump & Beyond: Having a C-Section | Boston Medical Center"). Some signs that you may need to give birth early: - The baby keeps growing slower than normal - There are signs your placenta isn’t working well - You have other health problems, like high blood pressure or diabetes Baby’s Estimated Size on the UltrasoundRecommendation for When to Give Birth- Baby (overall) is smaller than the 3rd percentile 37 weeks- Baby is normal-sized but their **abdomen is smaller** than the 10th percentile, *or* - Baby’s **overall size** is between the 3rd and 10th percentile 38–39 weeksIn addition to your baby’s size, if your provider sees other concerning things on the ultrasound, **they may recommend birth before 37 weeks**. This is fairly rare. You can ask your provider for more information.If your care team recommends that you give birth early, they will work with you to decide the best time and plan. The goal is for you to feel **informed and supported** every step of the way. ## A Final Note Estimating baby growth is a tricky process. Sometimes babies who look small early in the pregnancy can “catch up” later in the pregnancy, returning to normal growth. If this happens, you can go back to regular prenatal care. fetal-growth-restriction