Gestational Diabetes

Gestational diabetes is a pregnancy-induced blood sugar disorder that affects as many as 9.2% of all pregnancies. The disorder usually presents itself in the third trimester, when babies begin to grow at a faster rate.  During pregnancy, the placenta produces hormones that can affect the body’s ability to process glucose. These hormones are vital for the development of a child in utero, but may simultaneously (and detrimentally) cause insulin resistance, which increases the mother’s blood sugar levels and can lead to gestational diabetes.

When gestational diabetes occurs, the mother’s pancreas creates excess insulin that is not effective in reducing blood sugar levels. Instead, the extra glucose that is not broken down will cross the placental barrier and be transferred to the child. In turn, the fetus will begin to create extra insulin of its own. The excess energy created by this process is stored as fat and causes a child to grow bigger than expected, known as fetal macrosomia.

A gestational diabetes test is a standard procedure during the end of the second trimester, but pregnant mothers may be screened as early as 13 weeks’ gestation if medical providers believe that a mother is at greater risk of developing the disorder. Typically, healthcare providers will perform a 1-hour glucose tolerance test. If the test results are abnormal, a 3-hour glucose tolerance test will be ordered.

The goal of treatment for mothers with gestational diabetes is to prevent the risks that accompany the condition, including fetal macrosomia. Usually, a doctor will recommend a change of diet along with exercise, and/or prescribe oral medication to manage the risks. If the condition is not managed with these interventions, insulin therapy is typically administered.

Due to the risk of fetal macrosomia, it is recommended that babies be delivered at 38 weeks of gestation. A study out of the University of New Mexico found that prolonging a pregnancy past 38 weeks does not decrease the cesarean rate and delivery after 38 weeks increases the risk of fetal macrosomia.

At birth, infants born to mothers with gestational diabetes are predisposed to complications. These complications may include a higher risk of shoulder dystocia, instrumental delivery by forceps or vacuum, birth by caesarian section, very low blood glucose levels, jaundice, hypocalcemia, breathing problems, and other issues. A study out of the University of Colorado School of Medicine found that babies born to mothers with gestational diabetes have a higher risk of developing obesity and type 2 diabetes due to the increased amount of insulin they produce.

One of the most compelling reasons that children born to mothers with gestational diabetes should be closely monitored in utero is the risk of cephalopelvic disproportion, or when a baby’s head is too large to fit through the mother’s pelvis. Babies that are too large to be born vaginally may experience complications if a trial of labor is attempted, including a loss of fetal oxygenation and subsequent hypoxic-ischemic injury. Injuries from attempted vacuum or forceps deliveries are more common with macrosomic infants as well. Careful management and monitoring of babies both prenatally and during labor and delivery can help minimize these types of complications.