Gestational Diabetes Management

Introduction

Gestational diabetes mellitus (GDM) is a condition that requires careful management to reduce the risk of adverse perinatal outcomes, as recommended by the American Diabetes Association 1, 2
Untreated GDM significantly increases the risk of serious perinatal complications for the infant, including increased risks of perinatal mortality, macrosomia, and metabolic complications, with a 2-4 fold higher morbidity rate compared to treated cases 3, 4, 5

If high-risk factors present, screen for pre-existing diabetes in the first trimester, as recommended by the American Diabetes Association 2
Gestational diabetes screening should be performed between 24-28 weeks of gestation for optimal outcomes, as delayed diagnosis can lead to increased risks, according to the American College of Obstetricians and Gynecologists 4
The risk of congenital anomalies is slightly increased in GDM, likely due to undiagnosed pre-existing type 2 diabetes, and pre-existing diabetes carries higher risks than gestational diabetes, with obesity compounding risks independent of diabetes status 5

Patients with GDM should undergo ultrasound measurement of fetal abdominal circumference starting in the second and early third trimesters and repeated every 2-4 weeks to guide management decisions and reduce risk of adverse perinatal outcomes, as recommended by the American Diabetes Association 1
Fetal ultrasound screening for congenital anomalies is recommended for women with GDM who present with A1C ≥ 7.0% or fasting plasma glucose ≥ 120 mg/dl, according to the American Diabetes Association 1
Mothers should monitor fetal movements during the last 8-10 weeks of pregnancy and report any reduction immediately, as advised by the American Diabetes Association 1
Beyond 40 weeks, intensify fetal surveillance if pregnancy continues, as recommended by the American Diabetes Association 1

Begin ultrasound assessment in the second trimester and continue into the early third trimester, with every 2-4 weeks starting from second trimester, as recommended by the American Diabetes Association 1
After GDM diagnosis, begin serial growth ultrasounds every 2-4 weeks, according to the American Diabetes Association 1

Randomized controlled trials have demonstrated that modification of metabolic management based on fetal growth measurements can improve perinatal outcomes, as reported by the American Diabetes Association 1
Do not rely solely on maternal glucose levels; fetal growth parameters provide crucial additional information for management, as emphasized by the American Diabetes Association 1
Avoid inadequate ultrasound surveillance in GDM patients, even when glucose control appears adequate, as warned by the American Diabetes Association 1
Strict control of glucose levels in women with GDM is recommended, with a strength of evidence rated as high, according to the American Diabetes Association 1
Tight glycemic control through diet, exercise, and insulin if necessary, with target blood glucose levels of fasting <95 mg/dl and 1-hour postprandial <140 mg/dl, can reduce the risk of fetal macrosomia and its associated complications 6, 7

The following guidelines are recommended for delivery:

Estimated Fetal Weight (EFW)	Recommendation
<5,000g	Labor and vaginal delivery are not contraindicated, allow trial of labor with close monitoring
>5,000g	Consider prophylactic cesarean delivery, particularly recommended for primiparous women
<4,500g	Trial of labor is appropriate, delivery at 38 weeks is recommended to prevent further fetal growth
>4,500g	Consider prophylactic cesarean delivery, with EFW >4,500g, a prolonged second stage or arrest of descent is an indication for cesarean delivery

1, 7, 8

Immediate blood glucose monitoring in the first hour of life, continued monitoring every 2-3 hours during the first 24 hours, and early initiation of feeding, preferably breastfeeding, are crucial for newborns of mothers with GDM 9, 5
The American Academy of Pediatrics recommends early monitoring of glucose levels in the first hour of life and every 2-3 hours during the first 24 hours, with a strength of evidence rated as high 10

Long-term follow-up is recommended to monitor growth and development during childhood, educate parents about future risks of obesity and diabetes, and promote healthy lifestyle habits from an early age 5
Children of mothers with GDM are at increased risk of childhood obesity, developing type 2 diabetes in adolescence and adulthood, and metabolic syndrome and cardiovascular disease 6, 1