Diabetes in pregnancy (GDM, T1DM, and T2DM): Clinical sciences

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Introduction0:00–0:51

Diabetes in pregnancy is characterized by hyperglycemia during gestation. Diabetes that initially arises during pregnancy is called gestational diabetes mellitus, or GDM.
GDM develops in at-risk patients due to worsening insulin resistance that occurs in the second and third trimesters. Individuals might also present to obstetric care with type 1 or type 2 diabetes, which is referred to as pregestational diabetes.
All types of diabetes in pregnancy increase the risk of complications, including fetal macrosomia, shoulder dystocia, preeclampsia, and cesarean birth.
Pregestational diabetes has additional risks of congenital malformations, spontaneous abortion, and stillbirth. Your first step in evaluating a patient with a chief concern suggesting diabetes in pregnancy is to obtain a focused history.

Focused History0:51–1:42

Start by determining if the patient has GDM or pregestational diabetes, and then review recent blood glucose measurements.
Patients with diabetes in pregnancy usually check a fingerstick glucose four to five times daily, including fasting; postprandial, or after each meal; and sometimes at bedtime.
Most patients keep a glucose log, or you can scroll through glucose readings on their glucometer. Target glucose levels include a fasting glucose of less than 95 and either a one-hour postprandial glucose of less than 140 or a two-hour postprandial glucose that’s less than 120.Individuals with GDM who consistently achieve target glucose levels with diet and exercise have A1GDM.

A1GDM1:42–3:49

A1GDM is also called diet-controlled GDM because blood glucose levels are adequately controlled without medication. During the antepartum period, a patient with A1GDM should continue previously prescribed lifestyle modifications, including a carbohydrate-controlled diet and 30 minutes of moderate-intensity aerobic exercise at least 5 days per week, such as walking 10 to 15 minutes after each meal.
Advise the patient to continue self-monitoring of fasting and postprandial glucose levels to assess the response to lifestyle interventions.
You can modify the frequency of glucose monitoring if a patient’s glucose remains well controlled with diet and exercise.Because of the higher risk of fetal macrosomia and shoulder dystocia, you should assess fetal growth by ultrasound in the late third trimester.
If the estimated fetal weight is 4,500 grams or greater, counsel the patient regarding the risks and benefits of a scheduled cesarean delivery to reduce the risk of birth trauma.
Patients with A1GDM should deliver from 39 to 40 and 6/7 weeks. Once the patient with A1GDM is admitted for delivery, check their initial glucose level and repeat as indicated.
Most patients with A1GDM remain euglycemic throughout labor. After delivery, hyperglycemia associated with both types of GDM frequently resolves.
However, up to one-third of patients with GDM will have impaired glucose metabolism at postpartum screening. Therefore, all patients with GDM should undergo screening for diabetes at 4 to 12 weeks postpartum with a 2-hour oral glucose tolerance test.
Even if hyperglycemia is not noted, patients with GDM are at risk for developing diabetes years later. On the flip side, patients with GDM who don’t consistently achieve target glucose levels after lifestyle changes have A2GDM.
A2GDM requires the addition of pharmacotherapy along with diet and exercise to maintain blood glucose at target levels. Insulin is first-line therapy because it doesn’t cross the placenta and it can achieve tight metabolic control.

A2GDM3:49–5:31

Metformin is a second-line option, but it crosses the placenta, and the long-term effects after fetal exposure are unknown.
Metformin is a reasonable choice for patients who decline, can’t afford, or are unable to safely administer insulin. Patients with A2GDM should continue a carbohydrate-controlled diet and regular exercise.
Additionally, individuals should monitor fasting and postprandial glucose so pharmacotherapy can be titrated to achieve target glucose levels.
Suboptimal glucose control increases the risk of fetal demise. Therefore, all patients who require pharmacotherapy should undergo antepartum fetal surveillance, usually starting at 32 weeks of gestation.
As before, assess fetal growth by ultrasound in the late third trimester, and counsel the patient on the risks and benefits of elective cesarean birth if the estimated fetal weight is 4,500 grams or more.
The timing of delivery for patients with A2GDM depends on the response of glucose levels to diet, exercise, and pharmacotherapy.
If a patient with A2GDM consistently achieves target glucose levels, schedule delivery between 39 and 39 and 6/7 weeks. On admission, check the glucose level, and repeat during intrapartum as indicated to ensure glucose levels remain below 110, minimizing the risk of neonatal hypoglycemia.

A2GDM adequate response5:31–6:10

Some patients may need a sliding scale of insulin. After delivery, patients with A2GDM should undergo a 2-hour oral GTT at 4 to 12 weeks postpartum to evaluate for diabetes.
On the other hand, if a patient with A2GDM doesn’t consistently achieve target glucose levels despite diet, exercise, and pharmacotherapy, schedule delivery from 37 to 38 and 6/7 weeks.
Delivery as early as 34 weeks can be appropriate for patients with abnormal antepartum fetal testing or failed in-hospital improvement of glucose control.Check glucose on admission and every 1 to 2 hours in active labor, and administer insulin from a sliding scale as needed to maintain the patient’s glucose below 110.

A2GDM inadequate response6:10–7:01

After delivery, insulin can be discontinued. Be sure to order a 2-hour oral GTT between 4 and 12 weeks postpartum to evaluate for diabetes.
Now that we’re done with GDM, let’s talk about patients with pregestational diabetes. At the first prenatal visit, review the patient’s current medications and adjust as necessary to ensure that all medications are acceptable for treatment in pregnancy.
Next, obtain initial labs, including a hemoglobin A1c to confirm recent average blood glucose levels; thyroid function tests; baseline kidney function evaluation with serum creatinine, and a 24-hour urine test for total protein and creatinine clearance.
Be sure to repeat these tests at regular intervals to assess for changes. Also, refer the patient to an ophthalmologist for a comprehensive dilated eye exam in the first trimester, and monitor closely throughout pregnancy if retinopathy is present.

Pregestational diabetes7:01–10:06

Now, since pregestational diabetes is a risk factor for myocardial infarction in pregnancy, consider ordering a baseline ECG, especially in patients with longstanding diabetes complicated by nephropathy and chronic hypertension.
Pregestational diabetes also puts a patient at a higher risk for spontaneous abortion, so you should order a first-trimester ultrasound to confirm viability and to accurately date the pregnancy.
Finally, educate the patient and their family about the signs and symptoms of hypoglycemia and diabetic ketoacidosis. Here’s a clinical pearl!
Preconception counseling for patients with pregestational diabetes is essential because hyperglycemia adversely affects organogenesis, which occurs at 3 to 8 weeks of gestation.
Patients should be counseled to maintain their HbA1c under 7 before conception to reduce the risk of congenital malformations.Antepartum management of patients with pregestational diabetes usually includes insulin pharmacotherapy administered subcutaneously or with an insulin pump.
Metformin is a second-line option, but only for patients with type 2 diabetes. Lastly, because pregestational diabetes increases the risk of preeclampsia, start low-dose aspirin between 12 to 28 weeks.Next, patients should continue a carbohydrate-controlled diet and perform regular exercise in addition to recording daily fasting, postprandial, and bedtime glucose measurements.
Also, obtain a detailed fetal anatomical ultrasound with fetal echocardiography at 18 to 20 weeks to evaluate for congenital anomalies, and start antepartum fetal surveillance at 32 weeks.
Finally, order an ultrasound in the late third trimester for fetal growth and amniotic fluid volume. Consider cesarean birth if the estimated fetal weight is 4,500 grams or greater.
It’s important to assess the response to therapy by reviewing glucose logs every 1 to 2 weeks. Patients who consistently meet target glucose levels and have no other comorbidities can deliver between 39 to 39 and 6/7 weeks.
Check the glucose at admission and recheck every hour intrapartum to maintain a blood glucose of less than 110, using a sliding scale of insulin.
After delivery, insulin requirements decrease rapidly, so give one-third to one-half of the pre-delivery insulin or metformin regimen, and adjust based on postpartum glucose levels.
Patients can resume routine diabetes management after hospital discharge. Now, If a patient with pregestational diabetes has not consistently achieved target glucose levels, or if vasculopathy, nephropathy, or a history of prior stillbirth is present, the patient should undergo delivery from 36 to 38 and 6/7 weeks.

Adequate response10:06–10:45

Note that delivery as early as 34 weeks is considered only for individuals with abnormal antepartum fetal testing or failed in-hospital improvement of glucose control.
Also, monitor the patient’s glucose at admission and hourly during active labor, using an insulin sliding scale to keep glucose levels below 110.
After delivery, reduce the insulin dosage and adjust as needed. These patients can subsequently return to routine diabetes care.
Alright, as a quick recap…. Diabetes mellitus, either gestational or pregestational, is a common medical condition encountered during pregnancy.

Inadequate response10:45–11:37

Antepartum management for all patients with diabetes in pregnancy includes a carbohydrate-controlled diet and regular exercise.
Further care depends on how well blood glucose is controlled as the pregnancy progresses. Timing of delivery should balance the risks of preterm birth with the risks of fetal demise.
Postpartum, for patients with gestational diabetes, be sure to perform a 2-hour GTT, while patients with pregestational diabetes may return to their routine medical management.
These patients can subsequently return to routine diabetes care All right As a quick recap diabetes mellitus either gestational or pre gestational is a common medical condition encountered during pregnancy Antepartum management for all patients with diabetes in pregnancy includes a carbohydrate control diet and regular exercise Further care depends on how well blood glucose is controlled As the pregnancy progresses timing of delivery should balance the risks of preterm birth with the risks of fetal demise postpartum for patients with gestational diabetes Be sure to perform a two hour G TT while patients with preg investigational diabetes may return to their routine medical management

Review11:37–12:18