Gestational diabetes mellitus and COVID-19: The epidemic during the pandemic

Table 1 Variations between type 2 diabetes mellitus and gestational diabetes mellitus

	Type 2 diabetes mellitus	Gestational diabetes mellitus
Occurrence	Generally, develops after age 40, but can occur at any age	Develops during pregnancy, typically after the 20th wk of gestation
Prevalence	Affects approximately 90% of people with diabetes	Affects approximately 2%-10% of pregnancies
Risk factors	Family history, obesity, physical inactivity, high blood pressure, and ethnicity	Family history, previous history of gestational diabetes, obesity, older maternal age, and certain ethnicities
Symptoms	Fatigue, increased thirst, frequent urination, blurred vision, slow healing wounds	Often asymptomatic, but may cause increased thirst, frequent urination, and increased hunger
Diagnosis	Blood tests measuring fasting blood glucose and hemoglobin A1C levels	Oral glucose tolerance test usually performed between 24-28 wk of gestation
Treatment	Lifestyle changes, medication, and/or insulin therapy	Lifestyle changes, close monitoring of blood glucose levels, and medication/insulin therapy if necessary
Potential complications	Cardiovascular disease, neuropathy, retinopathy, kidney disease, and foot ulcers	Preeclampsia, premature delivery, macrosomia, and increased risk of developing type 2 diabetes later in life

The table summarizes key differences between type 2 diabetes mellitus and gestational diabetes mellitus, including occurrence, prevalence, risk factors, symptoms, diagnosis, treatment, and potential complications.

Table 2 Risk factors for gestational diabetes mellitus

Risk factors for GDM	Description
Increasing maternal age	Increases in gestational diabetes were seen in each maternal age group, and rates rose steadily with maternal age; in 2021, the rate for mothers aged ≥ 40 yr (15.6%) was nearly six times as high as the rate for mothers aged < 20 yr (2.7%)[16,25]
Past medical history of GDM in a previous pregnancy OR family history of type 2 DM	The strongest risk factor for gestational diabetes mellitus, with reported recurrence rates of up to 84%[26]
Race/ethnicities at increased risk for development of GDM	Women of Hispanic[17], other than white European origin[18], Asian[19], and indigenous descent[17-20]
Prevalence of GDM by ethnicity	The highest prevalence using the 2000 ADA diagnostic criteria among Filipinas (10.9%) and Asians (10.2%), followed by Hispanics (6.8%), non-Hispanic Whites (4.5%), and Black Americans (4.4%)[28]

The table presents risk factors associated with gestational diabetes mellitus (GDM) and the prevalence of GDM by ethnicity. Factors include increasing maternal age, past history of GDM, family history of type 2 diabetes, and specific ethnicities at higher risk for GDM development. These factors aid in identifying individuals at risk for GDM. GDM: Gestational diabetes mellitus; ADA: American Diabetes Association; DM: Diabetes mellitus; OR: Operating room.

Table 3 Gestational diabetes mellitus trends and statistics from 2016 to 2020

Year	Total births	GDM cases	GDM rate (%)	Confidence interval	Not stated cases
2016	3945875	234847	6.0	5.9-6.0	3781
2017	3855500	244716	6.4	6.3-6.4	3711
2018	3791712	252522	6.7	6.6-6.7	2882
2019	3747540	258676	6.9	6.9-6.9	3284
2020	3613647	281789	7.8	7.8-7.8	4063
Change, %	-8.6	+19.8	+30.0	N/A	+7.5

GDM: Gestational diabetes mellitus; N/A: Not applicable.

Table 4 Dosing recommendations for insulin and oral agents in management of diabetes during pregnancy

Drug class	Drug	Dosing
	Insulin
Rapid-acting insulin	Insulin lispro	First trimester 0.7 units/kg/d. 14-18 wk 0.8 units/kg/d. 26-27 wk 0.9 units/kg/d. 36-37 wk until delivery 1 unit/kg/d[95]
	Insulin aspart
Short-acting insulin	Regular insulin	First trimester 0.7 units/kg/d. 14-18 wk 0.8 units/kg/d. 26-27 wk 0.9 units/kg/d. 36-37 wk until delivery 1 unit/kg/d[95]
Intermediate-acting insulin	NPH	Two thirds can be given prebreakfast and the remaining one third can be given during the pre-evening meal[95]
Long-acting insulin	Detemir	50% of total daily dose can be given in the pre-evening meal and the remaining 50% can be given as a basal insulin[95]
	Glargine
	Oral agents
Biguanide	Metformin	500 mg once or twice daily with an increase over 1 to 2 wk to a maximum daily dose of 2500 mg. 2000 mg if using metformin of extended release[90,92]
Sulfonylurea	Glyburide	Starting dose of 2.5 to 5 mg once daily with an increase to a maximum dose of 20 mg/d[96]

The table provides dosing information for various drugs in different drug classes used for the treatment of diabetes in pregnancy. The dosing recommendations include different trimesters and specific timeframes until delivery. NPH: Neutral protamine Hagedorn.