Gestational diabetes mellitus (GDM) has a range of risk factors and is associated with a frightening spectrum of maternal and neonatal possible outcomes.

The recognized risk factors for GDM are higher body mass index (BMI) before pregnancy, higher BMI at 28 weeks of gestation, maternal age over 25 years, family history of diabetes mellitus, past history of GDM, multiparity, twin/multiple pregnancy, polycystic ovarian syndrome, and ethnicities such as Asian, Hispanic, or African-American [1] [2] [3] [4]. Of note, the pre-pregnancy BMI of Asian women have a higher bearing on insulin resistance than that of Caucasian women and they experience insulin resistance at much lower BMIs than do their European counterparts [5].

Women who suffer from GDM experience a range of adverse effects during pregnancy. This is generally because GDM places them at a higher risk of experiencing pregnancy-related complications such as the need for caesarian/ operative vaginal delivery, pregnancy-induced hypertension, preeclampsia, and eclampsia. These women also experience adverse effects following pregnancy, most notably the increased likelihood of developing type 2 diabetes mellitus.

The undesirable effects faced by the child due to maternal GDM are macrosomia, shoulder dystocia, neonatal hypoglycemia, hyperbilirubinemia, increased risk of stillbirth, and increased risk of developing diabetes mellitus and obesity in early life [6] [7].

GDM has a number of guidelines for screening and diagnosing, with striking heterogeneity between the different recommendations. The recommendations from the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) have been endorsed by a number of professional bodies [8].

The recommendations put forth by IADPSG suggest universal screening for GDM. Pregnant women need to be screened at the first antenatal visit with the standard criteria used in the non-pregnant state i.e. a diagnosis of GDM is made by fasting plasma glucose (FPG) level ≥ 7.0 mmol/l (126 mg/dl), random plasma glucose ≥ 11.1 mmol/l (200 mg/dl), or HbA1c (glycosylated hemoglobin) ≥ 6.5%. The aim of screening at this time is to diagnose women with pre-existing diabetes.

If the results at this stage are negative, screening needs to be repeated at 24-28 weeks of gestation with the use of oral glucose tolerance test (OGTT). The following cut off values in the OGTT point towards the diagnosis of GDM: FPG (5.1 mmol/l [92 mg/dl]), one hour plasma glucose (10 mmol/l [180 mg/dl]), and two hour plasma glucose (8.5 mmol/l [153 mg/dl]). These cut off values have been endorsed by the World Health Organization (WHO).

Following the diagnosis of GDM, there are other associated tests that need to be performed in each trimester to identify risks to the mother or child. Regular blood glucose testing needs to be done, either with HbA1c testing or capillary blood glucose.

Important tests in the first and second trimester are spot urine protein to creatinine ratio and ultrasonography (US). US in the first trimester is important for dating and establishing viability while a second trimester US is essential for assessing anatomical abnormalities. Furthermore, US remains important in the third trimester to assess fetal growth.

The primary goal of treating gestational diabetes is to maintain normal blood sugar levels. This is often achieved through lifestyle modifications such as a balanced diet and regular physical activity. In some cases, medication or insulin therapy may be necessary. Regular monitoring of blood sugar levels is crucial to ensure effective management. Healthcare providers work closely with patients to develop personalized treatment plans.

With proper management, most women with gestational diabetes can have healthy pregnancies and babies. However, if left untreated, it can lead to complications such as high birth weight, preterm birth, and increased risk of developing type 2 diabetes later in life for both mother and child. Postpartum follow-up is important to monitor and manage any long-term health risks.

The exact cause of gestational diabetes is not fully understood, but it is believed to be related to hormonal changes during pregnancy. These changes can affect the body's ability to use insulin effectively, leading to insulin resistance. Factors such as obesity, a family history of diabetes, and advanced maternal age can increase the risk of developing gestational diabetes.

Gestational diabetes affects approximately 2-10% of pregnancies worldwide. The prevalence varies based on factors such as ethnicity, age, and lifestyle. It is more common in women of certain ethnic backgrounds, including Hispanic, African American, Native American, and Asian populations. The increasing rates of obesity and sedentary lifestyles contribute to the rising incidence of gestational diabetes.

During pregnancy, the placenta produces hormones that can lead to insulin resistance, a condition where the body's cells do not respond effectively to insulin. This resistance is normal to some extent, as it ensures adequate glucose supply to the growing fetus. However, in gestational diabetes, the resistance becomes excessive, leading to elevated blood sugar levels.

While gestational diabetes cannot always be prevented, certain lifestyle changes can reduce the risk. Maintaining a healthy weight before and during pregnancy, eating a balanced diet rich in whole grains, fruits, and vegetables, and engaging in regular physical activity are key preventive measures. Women with risk factors should discuss preventive strategies with their healthcare providers.

Gestational diabetes is a temporary form of diabetes that occurs during pregnancy. It requires careful monitoring and management to prevent complications for both mother and baby. With appropriate treatment, most women can have healthy pregnancies. Understanding the risk factors and adopting a healthy lifestyle can help reduce the likelihood of developing gestational diabetes.

If you are pregnant or planning to become pregnant, it's important to be aware of gestational diabetes. Regular prenatal check-ups and screenings are essential for early detection and management. If diagnosed, work closely with your healthcare team to develop a treatment plan that includes a healthy diet, regular exercise, and possibly medication. Remember, with proper care, you can have a healthy pregnancy and baby.

1. Metzger BE, Lowe LP, Dyer AR, et al. Hyperglycemia and adverse pregnancy outcomes. N Engl J Med. 2008;358:1991–2002.
2. Berkowitz GS, Lapinski RH, Wein R, Lee D. Race/ethnicity and other risk factors for gestational diabetes. Am J Epidemiol. 1992;135:965–973.
3. Cypryk K, Szymczak W, Czupryniak L, Sobczak M, Lewiński A. Gestational diabetes mellitus - an analysis of risk factors. Endokrynol Pol. 2008;59:393–397.
4. Callesen NF, Ringholm L, Stage E, Damm P, Mathiesen ER. Insulin requirements in type 1 diabetic pregnancy: do twin pregnant women require twice as much insulin as singleton pregnant women? Diabetes Care. 2012;35:1246–1248.
5. Retnakaran R, Hanley AJ, Connelly PW, Sermer M, Zinman B. Ethnicity modifies the effect of obesity on insulin resistance in pregnancy: a comparison of Asian, South Asian, and Caucasian women. J Clin Endocrinol Metab. 2006;91:93–97.
6. World Health Organization. Diagnostic criteria and classification of hyperglycaemia first detected in pregnancy: a World Health Organization Guideline. Diabetes Res Clin Pract. 2014;103:341–363.
7. O’Sullivan JB, Charles D, Mahan CM, Dandrow RV. Gestational diabetes and perinatal mortality rate. Am J Obstet Gynecol. 1973;116:901–904.
8. International Association of Diabetes and Pregnancy Study Groups Consensus Panel. Metzger BE, Gabbe SG, Persson B, Buchanan TA, Catalano PA, et al. International association of diabetes and pregnancy study groups recommendations on the diagnosis and classification of hyperglycemia in pregnancy. Diabetes Care. 2010;33:676–682.