Fetal growth problems occur when your baby isn't growing as expected and is either too small or too large for their gestational age. Small babies may have health problems at birth, while large babies may cause complications during delivery.
Babies who are small or large for their gestational age rarely cause noticeable symptoms. It’s important to attend all of your scheduled ob-gyn appointments so your doctor can take accurate measurements to estimate your baby’s gestational age and size.
Related services:
Fetal growth problems occur when your baby isn't growing as expected. They may be either too small or too large for their gestational age.
Gestational age is a term that describes how far along a pregnancy is. Gestational age measurements are in weeks, from the first day of the woman's last menstrual period to the current date. A normal pregnancy ranges from 38 to 42 weeks.
Babies that are small for their gestational age are at an increased risk of certain health problems, including:
Small babies also can have trouble maintaining their body temperature after birth.
When a baby is too large for their gestational age, it could indicate gestational diabetes. Gestational diabetes can cause your baby to grow too big for you to deliver them vaginally. Your doctor may need to do a cesarean section or induce an early labor.
Approximately 24% of all babies born are small for their gestational age, according to the National Institutes of Health (NIH). Gestational diabetes affects between 2% and 10% of pregnancies each year, according to the Centers for Disease Control and Prevention (CDC), and is the primary cause of large gestational size babies.
Sometimes, a fetus grows in an unexpected way — either smaller or larger than expected for its gestational age.
The term for when fetuses are small in gestational size is intrauterine growth restriction (IUGR). Very small babies may not develop properly and have problems at birth.
Several factors during pregnancy may cause a small gestational size baby, including:
When a baby is large for its gestational age, the mother may have gestational diabetes. This can cause complications during labor or preterm labor.
The exact cause of gestational diabetes is unknown, but lifestyle and genetics each play a role.
When you’re pregnant, your growing baby’s size and weight depend on many factors.
These include your:
Risk factors for a small baby include factors that are both in and out of your control.
Lifestyle choices within your control include:
There are also risk factors you can't control, like family history, genetics, and inborn chromosomal or birth defects.
Risk factors for a large baby include:
Left undiagnosed or untreated, you may give birth to a low-birthweight baby. Certain health problems that may affect small newborns include:
If your baby is too large, you may have trouble delivering vaginally. Your doctor may recommend a C-section or induce your labor early and prevent the baby from getting too big.
The best way to promote a healthy birth weight while your baby is still in the womb is to eat healthy foods so you both get plenty of nutrients.
Of particular importance is protein, which is critical for your baby’s growth. Good sources of protein include lean meats, seafood, and eggs. Beans, nuts, peas, seeds, and soy products are also great options.
Fetal growth problems may not cause any noticeable symptoms for you, but your doctor will notice any measurements that differ from your baby’s estimated gestational age. That’s why it’s so important for you to attend all of your scheduled ob-gyn appointments.
During your pregnancy, your doctor will monitor your baby’s growth by measuring your fundal height. This is the distance from your pubic bone to the top of your uterus.
Before birth, your provider also will use ultrasound to measure the size of your baby's head, abdomen, and thighbone. These measurements provide a picture of how well your baby is growing in the womb. Measurements that are smaller or larger than expected for your baby’s gestational age might indicate fetal growth problems.
Measurements that help screen for fetal growth problems are just one key reason why you should never skip ob-gyn appointments during or after your pregnancy.
According to the NIH, the weight for full-term infants born at the appropriate gestational age is usually between 2,500 grams (about 5.5 pounds or 2.6 kilograms) and 4,000 grams (about 8.75 pounds or 4 kilograms).
If your baby is larger than expected for its gestational age, your doctor will screen you for gestational diabetes with a glucose challenge test. All pregnant people receive a glucose test.
Glucose screening tests may vary slightly depending on your doctor. They generally include an initial challenge test that involves drinking a syrupy sweet glucose solution. An hour later, you'll have blood drawn to measure your blood sugar level.
A blood sugar level of 190 milligrams per deciliter, or 10.6 millimoles per liter, indicates gestational diabetes. A blood sugar level below 140 milligrams per deciliter (7.8 millimoles per liter) is usually considered within the standard range on a glucose challenge test.
If your blood sugar level is higher than expected, you'll need another glucose tolerance test to determine if you have gestational diabetes. Similar to the initial test, the follow-up test solution will have even more sugar.
Your doctor will check your blood sugar every hour for three hours. If at least two of the blood sugar readings are higher than expected, you'll get a diagnosis of gestational diabetes.
If your risk of getting gestational diabetes is average, your ob-gyn usually will order the glucose screening test during your second trimester. If you’re at higher risk due to family history, being overweight, or having had gestational diabetes with a prior pregnancy, they may order the screening earlier in your pregnancy.
Your doctor also may order an ultrasound to check the size of the baby. This is because a large baby getting stuck in the birth canal is a complication during vaginal delivery.
If your baby gets a diagnosis of fetal growth problems, your doctor will monitor your baby’s growth and development closely using ultrasound exams and other tests. They'll recommend measures you can take to minimize your and your baby's health risks.
If your baby is too small, your doctor may recommend more testing to determine whether your baby has health problems that require immediate treatment after birth.
If your baby is big for its gestational age and you have gestational diabetes, managing your condition with diet and exercise may help reduce your risk of having a larger baby. Your doctor also may induce labor early or recommend a cesarean section to prevent complications.
Last reviewed by a UPMC medical professional on 2024-09-05.
