Gestational diabetes mellitus (GDM) is one of the most common clinical conditions in pregnancy, with an increasing incidence due to the rise in overweight women and the postponement of motherhood. It is associated with perinatal complications and an increased risk of developing prediabetes and type 2 diabetes after delivery. Therefore, it is recommended that a 75g oral glucose tolerance test (OGTT-75g) be performed between 6 and 12 weeks postpartum. Despite its relevance, the rate of adherence to the test is low. Recent studies also indicate that measuring blood glucose one hour after the overload may be more sensitive than the traditional two-hour measurement in the early detection of dysglycemia. This study aims to evaluate strategies for qualifying the screening of metabolic changes in the postpartum period among women with GDM. The objectives are: (1) to analyze the impact of sending reminders via WhatsApp on the attendance rate for the 75g OGTT; and (2) to compare the frequency of prediabetes and diabetes diagnoses using two different diagnostic strategies applied to the same test-the traditional (fasting and 2-hour blood glucose) and the alternative (fasting and 1-hour blood glucose).

Gestational diabetes is one of the most common complications during pregnancy. With the increase in obesity and overweight in the population, as well as the postponement of motherhood, its incidence has been steadily increasing.

It is associated with complications such as polyhydramnios, macrosomia, premature labor, fetal death, hypoglycemia, and neonatal respiratory distress. Given the increase in the incidence of gestational diabetes and its clinical and epidemiological importance, a better understanding of the disease can promote improved care and prevention of its complications.

Women diagnosed with gestational diabetes mellitus (GDM) are at increased risk of developing prediabetes and type 2 diabetes in the years following childbirth. For this reason, national and international guidelines recommend performing a 75g oral glucose tolerance test (OGTT-75g) in the postpartum period, usually between six and 12 weeks after delivery, as a strategy for reclassifying glycemic status and early identification of persistent metabolic changes.

Despite the clinical relevance of the OGTT-75g in the follow-up of women with GDM, the rate of attendance for the test is notoriously low, especially in public health services. The reasons are multifactorial and include task overload in the postpartum period, logistical barriers, low risk perception, and the absence of systematic strategies to reinforce attendance. Simple interventions, such as sending reminders via electronic messages, have shown promise.

Considering the clinical and epidemiological relevance of GDM and these two complementary challenges-low attendance rates for screening and the diagnostic limitations of the current protocol-we propose two lines of investigation in this study:

1. to evaluate the impact of sending reminders via WhatsApp on the return rate for performing the 75g OGTT in the postpartum period; and
2. to compare the prevalence of glycemic changes identified by two different diagnostic strategies: the traditional one (fasting and two-hour blood glucose) and the new one (fasting and one-hour blood glucose). The results obtained may contribute to the qualification of care protocols and the prevention of adverse metabolic outcomes in women with a history of GDM.

Inclusion Criteria:

• Diagnosis of gestational diabetes mellitus, according to diagnostic criteria proposed by the IADPSG, namely:
• initial fasting blood glucose ≥ 92mg/dL OR
• 75g oral glucose tolerance test with fasting ≥ 92mg/dL or after 1h ≥ 180mg/dL or after 2h ≥ 153mg/dL Delivery performed at HC-FMUSP Scheduling of the 75g oral glucose tolerance test between 6 and 12 weeks after delivery Agreement with the informed consent form

Exclusion Criteria:

Withdrawal of consent Failure to complete the TOTG exam due to vomiting (exclusion from analysis 2 only)