Fasting Versus Fed: Effect of Oral Intake Prior to the Glucose Tolerance Test in Pregnancy

Studies suggest that the timing interval between oral intake and the 1-hour gestational diabetes screen may have a significant impact on gestational diabetes screening glucose levels. The investigators plan to conduct a prospective randomized trial comparing a 6-hour fast versus liberal oral intake within 2 hours prior to the glucose tolerance test in pregnancy in order to evaluate the effect of the fasting versus the fed state on routine gestational diabetes screening results.

Study Overview

• Status: Completed
• Conditions: Diagnoses Disease; Gestational Diabetes; Glucose, High Blood; Pregnancy in Diabetic
• Intervention / Treatment: Behavioral: Fasting before gestational diabetes screen; Behavioral: Per oral intake of food and drink

Detailed Description

Gestational diabetes (GDM) complicates approximately 400,000 pregnancies in the United States annually and is associated with significant adverse pregnancy outcomes, including increasing the lifetime risk of type 2 diabetes. The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women undergo GDM screening between 24-28 weeks gestation utilizing a 1-hour oral glucose tolerance test that was designed to be administered without regard to the last meal or time of day. However, studies suggest that the timing of one's last meal prior to the 1-hour GDM screen may have a significant impact on GDM screening glucose levels. In addition, providers routinely alter the timing of the 1-hour GDM screen based on patients' self reported oral intake prior to the exam. The investigators plan to conduct a prospective randomized trial comparing a 6-hour fast versus liberal oral intake within 2 hours prior to the glucose tolerance test in pregnancy in order to evaluate the effect of the fasting versus the fed state on routine GDM screening results.

• Study Type: Interventional
• Enrollment (Actual): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

1. Pregnant patients 18 years and older
2. Singleton gestation
3. Pregnancy managed at Lucile Packard Children's Hospital (LPCH) Stanford outpatient obstetrics clinic
4. Planned delivery at Lucile Packard Children's Hospital (LPCH) Stanford Labor and Delivery unit

Exclusion Criteria:

1. Pregestational diabetes
2. Gestational diabetes diagnosed in the 1st trimester
3. Less than 18 years of age
4. Planned delivery outside LPCH
5. Diabetes medication use prior to pregnancy
6. Inability to give informed consent
7. Chronic steroid use in pregnancy
8. Less than 24 weeks of gestation at the time of the 1 hour oral glucose tolerance test
9. Prior history of bariatric surgery
10. Multifetal gestation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: DIAGNOSTIC
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Fasting before gestational diabetes screen; Fasting for at least 6 hours prior to the 1-hour gestational diabetes screen.	Behavioral: Fasting before gestational diabetes screen; Fasting for at least 6 hours before 1-hour gestational diabetes screen.
ACTIVE_COMPARATOR: Fed before gestational diabetes screen; Liberal per oral intake within 2 hours of the 1-hour gestational diabetes screen.	Behavioral: Per oral intake of food and drink; Per oral intake of food and drink within 2 hours of gestational diabetes screen

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With a Positive Gestational Diabetes Mellitus (GDM) Screen (>= 140 mg/dL) on the 1 Hour 50-g Oral Glucose Tolerance Test (OGTT)	Number of positive GDM screen (>= 140 mg/dL) on the 1 hour 50-g oral glucose tolerance test conducted between 24-28 weeks gestation This outcome was assessed in pregnant participants.	Day of GDM screen (occurring between 24-28 weeks gestation)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Gestational Age at OGTT Screen		Day of GDM screen (occurring between 24-28 weeks gestation)
Mean Glucose Level at the OGTT Screen		Day of GDM screen (occurring between 24-28 weeks gestation)
Number of Participants With Positive GDM Diagnosis Based on the OGTT	This outcome was assessed in pregnant participants.	Day of GDM screen (occurring between 24-28 weeks gestation)
Average Time of Last Oral Intake Prior to the OGTT Screen	Average number of hours since the participant's last oral intake prior to OGTT screen	Day of GDM screen (occurring between 24-28 weeks gestation)
Number of Participants With Positive GDM Diagnosis	GDM diagnosis based on 1-hour OGTT ≥ 180 mg/dL or 2 elevated values on the 3-hour OGTT using Carpenter and Coustan criteria. This outcome was assessed in pregnant participants Carpenter and Coustan Criteria is as follows (if 2 or more values are elevated, this is gestational diabetes): Fasting glucose < 95;; One hour glucose < 180;; Two hour glucose < 155;; Three hour glucose < 140	Day of OGTT (occurring at 24-28 weeks gestation up to 42 weeks gestation)
Mean Gestational Age at Delivery		At time of delivery (Up to 42 weeks' gestation)
Number of Participants Who Delivered Vaginally	This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Who Delivered Via Operative Vaginal Birth	This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Who Delivered Vaginally After a Prior Cesarean Section	This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Who Delivered Via a Primary Cesarean Section	Primary = first Cesarean section for participant. This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Who Delivered Via a Repeat Cesarean Section	This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Complicated by Shoulder Dystocia at Delivery	Shoulder dystocia is a birth injury (also called birth trauma) that happens when one or both of a baby's shoulders get stuck inside the mother's pelvis during labor and birth. This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants Complicated by Third or Fourth Degree Perineal Laceration	A third degree tear is a tear or laceration through the perineal muscles and the anal sphincter. A fourth degree tear goes through the anal sphincter all the way to the anal canal or rectum. This outcome was assessed in pregnant participants.	At time of delivery (up to 42 weeks' gestation)
Number of Participants With Post-partum Hemorrhage	This outcome was assessed in pregnant participants after delivery.	Up to 6 weeks after delivery
Number of Participants Diagnosed With a Hypertensive Disorder of Pregnancy	This outcome was assessed in pregnant participants.	From time of GDM screen up to 6 weeks after delivery
Length of Postnatal Stay From Delivery to Discharge	Average number of days admitted in the hospital after delivery up to discharge	Up to 1 week after delivery
Number of Participants Who Had a Postpartum Readmission	This outcome was assessed in pregnant participants post-delivery.	From initial hospital discharge up to 6 weeks post-partum
Number of Participants With Type 2 Diabetes Mellitus Diagnosis Post-partum	This outcome was assessed in pregnant participants after delivery.	From time of delivery up to 6 weeks post-partum
Mean Neonatal Birthweight		Day of delivery (Within approximately 2 hours after delivery)
Number of Neonates With Birth Weight More Than 4000 Grams		Day of delivery (Within approximately 2 hours after delivery)
Number of Neonates Considered Large for Gestational Age (LGA)	LGA refers to neonatal birth weight larger than the 90th percentile for gestational age.	Day of delivery (Within approximately 2 hours after delivery)
Number of Neonates Considered Small for Gestational Age (SGA)	SGA are infants whose weight is < the 10th percentile for gestational age.	Day of delivery (Within approximately 2 hours after delivery)
Number of Neonates Admitted to the Neonatal Intensive Care Unit (NICU)		Up to 28 days after delivery
Number of Neonates With Hyperbilirubinemia		Up to 28 days after delivery
Number of Neonates With Hypoglycemia		Up to 28 days after delivery
Number of Neonates Diagnosed With Respiratory Distress Syndrome		Up to 28 days after delivery
Number of Neonates Exclusively Breastfeeding at Time of Hospital Discharge		Up to 28 days after delivery

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Investigators: Principal Investigator: Yair Blumenfeld, MD, Associate Professor

Study record dates

Study Major Dates

• Study Start (ACTUAL): November 2, 2020
• Primary Completion (ACTUAL): June 21, 2021
• Study Completion (ACTUAL): November 1, 2021

Study Registration Dates

• First Submitted: September 4, 2020
• First Submitted That Met QC Criteria: September 4, 2020
• First Posted (ACTUAL): September 14, 2020

Study Record Updates

• Last Update Posted (ACTUAL): November 21, 2022
• Last Update Submitted That Met QC Criteria: October 26, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Diabetes Mellitus; Pregnancy Complications; Diabetes, Gestational; Pregnancy in Diabetics
• Other Study ID Numbers: 57772; P30DK116074 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No