From the Guidelines
The most appropriate intervention for this patient is to start a prenatal vitamin containing at least 400 mcg of folic acid immediately and schedule glucose screening between 24-28 weeks gestation. Despite her concern that the prenatal vitamin caused her nausea, adequate folic acid supplementation is crucial during pregnancy to prevent neural tube defects, especially since she is already at 16 weeks gestation. The patient should be advised that her nausea is likely improving naturally as she enters the second trimester, and she could try taking the vitamin with food or before bedtime to minimize gastrointestinal side effects. Additionally, given her history of cold knife conization for cervical intraepithelial neoplasia 3, she should be monitored for cervical insufficiency during pregnancy, as this procedure can weaken the cervix and potentially lead to preterm birth. Serial cervical length measurements via transvaginal ultrasound may be warranted. Her family history of gestational diabetes also indicates that she should undergo glucose screening between 24-28 weeks gestation, though this is standard care for all pregnant women, as recommended by the most recent guidelines 1. The two-step approach for glucose screening, which includes a 50-g glucose challenge test followed by a 100-g oral glucose tolerance test (OGTT) if the initial test is abnormal, is a commonly used method for detecting gestational diabetes, as outlined in the guidelines 1. However, the choice between the one-step and two-step approach may depend on regional preferences and the prevalence of gestational diabetes in the population, as noted in the guidelines 1. The prenatal vitamin is the most immediate intervention needed, as other routine prenatal care elements like genetic screening and anatomy ultrasound would be scheduled as part of standard care. It is also important to note that the patient's risk factors, including her family history of gestational diabetes, should be taken into account when determining the best course of care, as recommended by the guidelines 1.
Some key points to consider in the management of this patient include:
- Starting prenatal vitamins with at least 400 mcg of folic acid immediately
- Scheduling glucose screening between 24-28 weeks gestation
- Monitoring for cervical insufficiency due to her history of cold knife conization
- Considering her family history of gestational diabetes when determining the best course of care
- Following the most recent guidelines for the diagnosis and management of gestational diabetes, as outlined in 1 and 1.
From the Research
Patient Assessment and Interventions
The patient is a 28-year-old woman, gravida 1 para 0, at 16 weeks gestation with a history of cervical intraepithelial neoplasia 3 and a family history of gestational diabetes mellitus. Given her family history, she is at increased risk for developing gestational diabetes mellitus (GDM) 2.
Screening for Gestational Diabetes
- The American College of Obstetricians and Gynecologists (ACOG) recommends screening for gestational diabetes between 24 and 28 weeks' gestation unless pregestational diabetes is present 2.
- The 1-step method is diagnostic and consists of a 75-g, 2-hour oral glucose tolerance test (OGTT), while the 2-step method consists of a 50-g, 1-hour glucose challenge test, followed by a 100-g, 3-hr OGTT if initial test results are positive 2.
- A study found that the 50-g glucose challenge test is acceptable to screen for GDM, but cannot replace the OGTT 3.
Prenatal Vitamins and Blood Glucose
- Ingestion of prenatal vitamins produces a rise in blood glucose greater than that seen following ingestion of sucrose equal to the carbohydrate content of prenatal vitamins 4.
- It would appear prudent to prescribe a prenatal vitamin with a low relative glycemic index (RGI) 4.
Patient History and Physical Examination
- Taking a thorough patient history is fundamental for the accurate diagnosis and effective management of health conditions 5.
- The patient's history of cervical intraepithelial neoplasia 3 and subsequent negative Pap tests, as well as her family history of gestational diabetes mellitus, should be considered in her prenatal care 6.