Comparison of the Screening Tests for Gestational D.M One Step and Two Step Methods among the Pregnant Women

Research Article

Austin J Obstet Gynecol. 2022; 9(1): 1200.

Comparison of the Screening Tests for Gestational D.M One Step and Two Step Methods among the Pregnant Women

Zeinab Mahmoud Elbaz*

Department of Gynecology, Alexandria University, Egypt

*Corresponding author: Zeinab Mahmoud Elbaz, Department of Gynecology, Alexandria University, Alexandria, Egypt

Received: June 27, 2022; Accepted: July 25, 2022; Published: August 01, 2022


Gestational Diabetes Mellitus (GDM) has defined by the World Health Organization (WHO) in 1999 as any degree of carbohydrate intolerance resulting in hyperglycemia of variable severity, with onset or first recognition during pregnancy, excluding overt diabetes in early pregnancy [1]. Its prevalence varies worldwide and also with the testing method and diagnostic criteria used [2]. Extensive research has demonstrated that GDM is associated with short- and longterm complications concerning both mother and child. Screening and treating GDM are an effective means to prevent short term complications and a significant opportunity for intervention in order to avoid long term ones [3]. Short term complications of GDM such as macrosomia, shoulder dystocia, birth trauma, increased rate of cesarean section, in uterine fetal death, neonatal hypoglycemia, congenital anomalies, and respiratory distress syndrome, and to the occurrence of maternal hypertensive disorders [4]. Long term complications include maternal increased risk of developing Type 2 Diabetes (T2DM) later in life and major potential metabolic pattern disorders in the offspring, which would lead to increased risks of abnormal glucose tolerance, obesity and metabolic syndrome [5].

The American College of Obstetricians and Gynecologists (ACOG) recommends a two-step approach for screening and diagnosis of GDM in moderate and high-risk population, first screening with the 50-g Glucose Challenge Test (GCT), those individuals meeting or exceeding the screening threshold (>140 mg/d) undergo a 100-g 3-h diagnostic oral glucose tolerance test [2]. On the other hand, World Health Organization (WHO) recommends a single-step 75-g 2-h OGTT to be performed in fasting state [6].

The International Association of Diabetes and Pregnancy study groups (IADPSG) in 2010 is an international consensus group with representatives from multiple obstetrical and diabetes organizations, has proposed guidelines relied on a study of Hyperglycemia and Adverse Pregnancy Outcomes (HAPO study) to reach a single consensus and suggested new criteria for the diagnosis of diabetes in pregnancy based on the association of maternal glycaemia with perinatal outcomes [7]. It recommends screening high-risk women at the first visit, to screen universally at 24- to 28-week gestation, with use of the 75-g oral glucose tolerance test for the diagnosis of gestational diabetes (one-step approach) [8,9].

Applying IADPSG criteria invariably increases the prevalence of GDM, since it includes milder cases of GDM [10,11]. This approach has not been endorsed by ACOG [5]. ACOG emphasizes that 18 percent of all pregnant women will be diagnosed with GDM using the IADPSG criteria due to a lower threshold. They believed that the one-step approach with new criteria would increase health care costs in the absence of solid evidence for improvements in maternal or neonatal outcomes [12].

ADA guidelines now leave the choice between the one-step IADPSG screening strategy and the two-step screening strategy [13]. Since the new strategy using 75 g OGTT as one-step screening is still controversial, present study was undertaken to compare the onestep screening procedure (IADPSG recommended) with two-step procedure (ACOG recommended) in addition to incidence, maternal and fetal outcome of patients with GDM.

Materials and Methods

A prospective randomized study was conducted on 600 pregnant women attending antenatal care clinic (ANC), at Shatby University hospital between March 2019 and December 2019, were counseled and written informed consent was taken.

Inclusion criteria included women between 18-38years, singleton pregnancy with low or average risk for GDM which was defined by any pregnancies that had no criteria for the high risk for GDM as mentioned later, and gestational age between 24 and 28 weeks of gestation, based on regular menstrual period and ultrasound examination in the first half of pregnancy.

Exclusion criteria were pregnant women with high risk for GDM, including known cases of pre-gestational diabetes or high risk for gestational diabetes mellitus such as previous child birth weight of more than 4,000 grams, previous diagnosis of GDM, obesity or BMI 30 kg/m2 or more, previous neonatal hypoglycemia, and first degree relatives with diagnosed DM or glucosuria.

According to computer-generated random number table; group A comprised of300 patients screened with one-step approach for GDM and group B included 300 women screened by two-step approach.

Group A One-step screening procedure (IADPSG recommended) was based on 75 gram two-hour oral glucose tolerance test (75 g OGTT) with at least one abnormal result: fasting plasma glucose ≥92 mg/dl, but <126 mg/dl or one-hour OGTT ≥180 mg/dl or two-hour OGTT ≥153 mg/dl. If any one of the above values was abnormal, then subjects were labeled as having GDM.

Group B The two-step approach was as follows: firstly, a 50 g oral Glucose Challenge Test (GCT) was performed regardless of the fasting status. If the plasma glucose level after 1 h was of ≤140 mg/ dl, it was considered as negative and needed no further test. If the level was>140 mg/dl, then 100 g OGTT was performed. The plasma glucose was measured after 100 g load at fasting, 1-, 2-, and 3-hour interval. The cut-off values were as follows: fasting ≥105 mg/dl, 1 h ≥ 188 mg/d, 2 h ≥ 165 mg/dl, and 3 h ≥ 140 mg/dl. A diagnosis of GDM was made if at least two values exceeded above plasma glucose concentration.

In cases of normal results, routine standard antenatal care was instituted, while women diagnosed as ‘gestational diabetes’ were followed in an antenatal clinic, the patients were taken care as a standard guideline for diabetic patients during pregnancy. At each antenatal visit, records of weight, blood pressure and obstetric examination were taken. BMI was measured at first ANC visit. Blood sugar profile which includes fasting blood sugar and post-meal blood sugar (2 h after meal) was monitored weekly in third trimester. Ultrasound for congenital malformation was done between 18 and 20 weeks. Blood glucose was usually controlled with diabetic diet and exercise. Insulin was used only when fasting glucose was more than 105 mg/dl, the target was to maintain fasting glucose <95 mg/dl or 2-hour postprandial glucose <120 mg/dl. Ultrasound monitoring for fetal well-being in the form of biophysical profile was done after 34 weeks on weekly basis. Women controlled on insulin were allowed to go in spontaneous labor till 38 weeks if there was no fetal or maternal indication of termination of pregnancy. Elective termination of pregnancy was done at 38 weeks if they did not go in labor. Further, women controlled on MNT alone were allowed to go in spontaneous labor up to 40 weeks, if antenatal period was uncomplicated.

The main outcome was the prevalence of GDM, and the secondary outcomes included birth weight, gestational age at delivery, rates of preterm birth (delivery before completed 37weeks), large-for gestational age (birth weight of greater than 90th percentile for each gestational week), cesarean section, pregnancy-induced hypertension and neonatal complications.


A total of 600 pregnant women were included in the study, 300 pregnant women were screened by one-step procedure group (A) and300 were screened by two-step procedure group (B). As regard baseline characteristics for all 600 women in both groups, which included maternal age, pre-pregnancy weight, maternal weight, BMI, gestational age at screening, and parity, fasting blood glucose were not statistically significantly difference including normal and GDM as shown in (Table 1). But as regard prevalence of GDM was higher in group A (one-step procedure) than in group B (two-step procedure) with statistically significantly difference (Table 2).