Gestational Diabetes in Primary Care

Paul Hicks, MD

Introduction

For every physician who provides care to pregnant women, a time will come when the challenges of both pregnancy and diabetes need to be addressed with a patient. Many physicians will make an immediate referral to a perinatologist. However, specialist referral is at best difficult, if not impossible, in many settings. This review is intended for those physicians who will be responsible for the ongoing care of an occasional patient with gestational diabetes and for all physicians who wish to expand their understanding of this disease.

The information in this review was obtained through a Medline search using the keywords "diabetes, gestational" for the period January 1990 through August 1999. Articles reviewed were limited to those with human subjects and published in English. Case-control and cohort studies, review articles, and technical bulletins were included, and additional articles were identified through review of the bibliographic references.

1 2 3 4 5 6 7 8 9

Next Section

Cite this: Gestational Diabetes in Primary Care - Medscape - Feb 23, 2000.

Table 1. Composition of Study Population by Race/Ethnicity With 50-g Oral Glucose Screening Test and 3-Hour Glucose Tolerance Test Results
Race/Ethnicity	N	Third-Trimester GST Result* (mg/dL)	Third-Trimester GST Result > 140 mg/dL	GDM Diagnosed in Patients With GST > 140 mg/dL	Prevalence of GDM Diagnosed in Third Trimester
White	654 (71%)	123.2±28.4	27.4%	17.3%	6.0%
Hispanic	512 (56%)	123.2±28.3	26.8%	18.2%	6.3%
Non-Hispanic	142 (15%)	123.5±28.5	29.6%	14.3%	4.9%
Black	120 (13%)	116.4±31.6	17.5%	42.9%	7.5%
Filipino	83 (9%)	127.6±26.3	31.3%	11.5%	3.6%
Asian^†	64 (7%)	134.7±25.0	40.6%	11.5%	4.7%

GST = to-g oral glucose screening test
*Mean + SD.
^†Asian includes subjects of Chinese, Japanese, Korean, Vietnamese, Thai, Cambodian, and Laotian ethnicity.; Reprinted with permission from Nahum and Huffaker.^[14]

Table 2. Recommended Race-Specific Glucose Screening Test Thresholds for Initiating 3-Hour Glucose Tolerance Testing, With Expected Yields of Positive Results by Race
	Blacks	Whites	Filipinos	Asians
Recommended upper limit threshold for normalcy of GST result (mg/dL)*	130	140	145	150
Expected proportion of gravidas exceeding threshold limit	24.2%	27.4%	27.7%	23.4%
Expected percentage of gravidas diagnosed with GDM in third trimester	7.5-8.3%	4.7%	3.6%	3.1%

*Plasma glucose oxidase values; Reprinted with permission from Nahum and Huffaker.^[14]

Table 3. Detection of Gestational Diabetes*
100-g oral glucose tolerance test	O'Sullivan Criteria	Carpenter Conversion
Fasting	105	95
1-hour	190	180
2-hour	165	155
3-hour	145	140

*Diagnosis of gestational diabetes is made when any 2 values are met or exceeded.; Reprinted with permission from American College of Obstetricians and Gynecologists.^[1]

Table 4. Caloric Restrictions in Obese and Nonobese Women With GDM
Distribution of Calories in a Diabetic Diet
Breakfast = 20% total kcal/day
Lunch = 25%
Supper = 25%
3 snacks, after each meal = 5% each
1 snack before bed = 15%

Adapted from Langer and Hod.^[29]

Table 5. Low-Dosage Constant Insulin Infusion for the Intrapartum Period*
Blood Glucose (mg/100 mL)	Insulin Dosage (U/hr)	Fluids (125 mL/hr)
< 100	0	Dextrose/Lactated Ringer's
100-140	1.0	Dextrose/Lactated Ringer's
141-180	1.5	Normal saline
181-220	2.0	Normal saline
> 220	2.5	Normal saline

*Dilution is 25 U of regular insulin in 250 mL of normal saline with 25 mL flushed through line administered intravenously. A finger-stick glucose test is performed every 1-2 hours. The insulin pump and intravenous solution are adjusted accordingly.; Adapted from Hollingsworth and Moore.^[62]

Table 6. Postpartum Evaluation for Carbohydrate Intolerance
Plasma glucose level*(mg/dL) in
Time Tested	No Diabetes	Impaired Glucose Tolerance	Diabetes Mellitus
Fasting	< 110	>/= 110 and < 126	>/= 126
2 h	< 140	140-199	>/= 200

*Values are based on a 2-h, 75-g oral glucose tolerance test.; Reprinted with permission from the American Diabetes Association.^[16]

Comments

Commenting is limited to medical professionals. To comment please Log-in.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....

Gestational Diabetes in Primary Care

Introduction

Tables

Tables

Tables

Tables

Tables

Tables

References

Authors and Disclosures

Authors and Disclosures

Comments

Email This

Feedback