Gestational Diabetes and Premature Birth

A diabetic pregnant woman is checking her blood sugar level (self glycemia).
GARO/PHANIE/Canopy/Getty Images

People with diabetes can have healthy pregnancies and healthy babies. The key is to keep diabetes under control to minimize or prevent complications. The more complicated diabetes is, the more problems it can cause.

While gestational diabetes needs to be followed closely, if it is controlled well with diet, exercise, and medications if necessary, it is not usually as serious as having pregestational diabetes (having type 2 or type 1 diabetes before becoming pregnant). Of course, there are still risks. Gestational diabetes, just like other types of diabetes, can lead to premature birth as well as other complications, especially if it goes untreated.

What Is Gestational Diabetes?

Your body uses sugar for energy. The sugar goes from your blood into your body's cells with the help of a hormone called insulin. Once the sugar is in the cells, it's converted to energy or stored. But, if the body doesn't make enough insulin, or it can't use the insulin well, then the sugar has trouble moving into the cells and stays in the blood instead. High levels of sugar in the blood is called diabetes mellitus.

Gestational diabetes mellitus (GDM) is diabetes that develops during pregnancy. After the pregnancy ends, gestational diabetes usually goes away, and blood sugar levels typically return to normal.

Risk of Preterm Labor

The complications caused by elevated blood sugar levels can increase the risk of premature birth. Studies show that the risk of premature delivery due to gestational diabetes is greater if a mother develops diabetes before the 24th week of pregnancy. After the 24th week, the chances of preterm birth go down.

How GDM Affects Babies

There are a number of complications that can result from gestational diabetes, some more serious for your baby than others:

  • Placental insufficiency: Problems with the placenta and the transfer of oxygen and nutrients are not likely to occur in gestational diabetes, as these are usually only seen in pregestational diabetes. But, in rare cases, if gestational diabetes comes on early and is not controlled, placental issues can lead to a smaller-than-average baby and intrauterine growth restriction (IUGR).
  • Macrosomia: Extra sugar in the pregnant parent's blood passes to the child. It can lead to excessive growth and a larger-than-average baby.
  • Delivery complications: Because of a baby's larger size, injuries during childbirth such as the shoulders getting stuck (dystocia) in the birth canal, bleeding in the head (subdural hemorrhage), or low oxygen (hypoxia) can occur. The delivery may also require the use of forceps or a vacuum, and the chances of a C-section are much higher.
  • Respiratory distress: In the weeks before a child is born, the lungs mature and produce something called surfactant. Surfactant coats the little sacs in the lungs and keeps them inflated when the baby breathes. If a baby is born early, their lungs may be immature and without enough surfactant. But, since diabetes also causes a decrease in the production of surfactant, even full-term babies can have breathing issues.
  • Hypoglycemia (low blood sugar): The baby makes extra insulin to handle all the sugar that the parent passes to the baby during pregnancy. After birth, the supply of sugar is cut off, but the child still makes extra insulin. The additional insulin is too much so it brings their blood sugar levels down too low (known as hypoglycemia)
  • Feeding problems: Prematurity, low blood sugar after birth, and difficulty breathing can make feedings more difficult.
  • Jaundice: The breakdown of red blood cells creates bilirubin. When there is a lot of bilirubin or the body cannot get rid of it fast enough, the level of bilirubin in the blood increases, causing the skin and eyes to look yellow. In cases of GDM, babies may take longer to get the extra bilirubin out of their body if they are premature, larger than average, or have low blood sugar.
  • Polycythemia: Sometimes a baby will be born with a high level of red blood cells as a result of a mom having diabetes. It can make the blood thick, and it can also contribute to breathing problems and jaundice.
  • Long-term concerns: Along with the complications of prematurity or a birth injury, there is also a greater chance of developing diabetes and being overweight later in life.

How GDM Affects Parents

There are several potential complications of gestational diabetes for the pregnant person.

  • Greater chance of delivering a preemie
  • Greater risk of getting gestational diabetes again with another pregnancy
  • Higher risk of developing other health issues such as high blood pressure and preeclampsia
  • Increased chance of type 2 diabetes following the pregnancy
  • More likely to have a C-section due to premature birth, complications, or a big baby

Risk Factors

Gestational diabetes can develop in anyone at any time during pregnancy. However, chances increase if you have risk factors, including:

  • Family history of diabetes
  • History of polycystic ovary syndrome (PCOS)
  • Previous child who was large for gestational age
  • Ethnic background with a higher rate of diabetes such as African American, Native American, Pacific Islander, Asian, or Hispanic
  • Gestational diabetes in a previous pregnancy
  • Multiple gestation (pregnant with more than one child)
  • Over 25 years old
  • Overweight


Since studies show that gestational diabetes affects about 9% of pregnancies, screening takes place during routine prenatal care. These screenings include:

  • Glucose blood test: A fasting blood sugar of more than 126 mg/dL, a non-fasting blood sugar of more than 200 mg/dL, or a hgb A1c of 6.5% or higher points toward gestational diabetes and usually means you'll need additional testing.
  • Glucose challenge test: Somewhere between the 24th and 28th week of pregnancy, your doctor will order a screening test. You will drink some liquid sugar, then you'll have a blood test an hour later to see how your body handles the sugar. If the results show the need for more testing, you'll have a similar but longer test called an oral glucose tolerance test (OGGT).
  • Physical examination: A thorough physical exam can give the doctor clues about your medical health and reveal any of the signs and symptoms of high blood sugar or insulin resistance.
  • Medical history: Your doctor will talk to you about your family and medical history to determine if you're at a higher risk.


If your doctor tells you that you have gestational diabetes, you will be monitored more closely to prevent complications. The most important thing you can do is try to keep your blood sugar levels under control.

  • Exercise and eat healthy to keep your sugar down.
  • Go to all of your prenatal appointments and follow the advice and instructions that your healthcare provider gives you.
  • Learn how to test your blood sugar levels.
  • You may have to take medication if your blood sugar levels cannot be controlled by diet and exercise alone.

Postpartum Care

After the birth, follow these guidelines to take care of yourself and your baby.

  • Breastfeed. Breastfeeding is safe even if your blood sugar levels remain high after pregnancy. Diabetes doesn't harm breast milk. Plus, breastfeeding is good for you and your baby. Not only can it help you lose weight, but it can also reduce the risk of type 2 diabetes for both you and your child later in life.
  • Maintain a healthy lifestyle. Continue to eat healthy foods and work out regularly. Diet and exercise can keep your blood sugar at healthy levels and reduce the risk of obesity and developing type 2 diabetes in the future.
  • See your doctor. Continue to follow up with your doctor to be sure your gestational diabetes goes away. If it doesn't, your doctor will continue to monitor your sugar and treat you for type 2 diabetes.
6 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wilcox G. Insulin and insulin resistanceClin Biochem Rev. 2005;26(2):19–39.

  2. Buchanan TA, Xiang AH, Page KA. Gestational diabetes mellitus: risks and management during and after pregnancyNat Rev Endocrinol. 2012;8(11):639–649. doi:10.1038/nrendo.2012.96

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Pregnancy if you have diabetes.

  4. Jaundice in newborns. Paediatr Child Health. 2007;12(5):409–420. doi:10.1093/pch/12.5.409

  5. Herath H, Herath R, Wickremasinghe R. Gestational diabetes mellitus and risk of type 2 diabetes 10 years after the index pregnancy in Sri Lankan women-A community based retrospective cohort studyPLoS One. 2017;12(6):e0179647. doi:10.1371/journal.pone.0179647

  6. Jäger S, Jacobs S, Kröger J, et al. Breast-feeding and maternal risk of type 2 diabetes: a prospective study and meta-analysisDiabetologia. 2014;57(7):1355–1365. doi:10.1007/s00125-014-3247-3

Additional Reading

By Donna Murray, RN, BSN
Donna Murray, RN, BSN has a Bachelor of Science in Nursing from Rutgers University and is a current member of Sigma Theta Tau, the Honor Society of Nursing.