Chapter 99: Comorbid Disorders in Pregnancy

INTRODUCTION

This chapter reviews the most common comorbid conditions encountered in pregnant women in the ED environment: diabetes and hypoglycemia; thyroid disorders; cardiac disorders and dysrhythmias; thromboembolism; asthma; urinary tract infections; headache; seizures; substance abuse; and intimate partner violence. Drug risk during pregnancy, lactation, and fetal effects of radiation are summarized based on currently available data. Resuscitation is covered in Chapter 25, “Resuscitation in Pregnancy.”

DIABETES IN PREGNANCY

The growing prevalence of gestational diabetes mellitus reflects the increase in obesity, sedentary lifestyles, and type 2 diabetes in the general population. Due to this increased prevalence and proposed new diagnostic criteria, it is estimated that any type of diabetes affects between 8% and 17% of pregnancies,¹ with 86% categorized as gestational diabetes mellitus.^2,3 Because many women do not receive screening for diabetes before pregnancy, it can be challenging to distinguish gestational from preexisting diabetes. Pregnant diabetics are at increased risk for several pregnancy complications, including pregnancy-induced hypertension, preeclampsia, preterm labor, spontaneous abortion, pyelonephritis, and diabetic ketoacidosis (DKA). The goal of treatment during pregnancy is to prevent spontaneous abortions, hyperglycemia-induced congenital abnormalities, and ketoacidosis and hypoglycemia.

The American College of Obstetricians and Gynecologists recommends the following goals for maintaining euglycemia in pregnant diabetic patients: a fasting blood glucose concentration of ≤95 milligrams/dL (5.27 mmol/L) and a 2-hour postprandial glucose concentration ≤120 milligrams/dL (6.66 mmol/L).³

A significant portion of gestational diabetics can be managed with diet alone if they can maintain glycemic goals with frequent glucose monitoring. When pharmacologic treatment is indicated, insulin is the preferred treatment for diabetes in pregnancy.

Among patients with preexisting type 1 and type 2 diabetes, the need for insulin increases throughout the course of pregnancy. In general, during the first trimester, the initial insulin requirement is 0.7 unit/kg/d. By late pregnancy, patients generally require 1 unit/kg/d.⁴

For basal insulin coverage, intermediate-acting neutral protamine Hagedorn (NPH) insulin has historically been considered first-line therapy and has been widely studied in this patient population. There is also recent literature supporting the use of long-acting insulin analogues, particularly insulin detemir (Levemir®), as an alternative. Insulin detemir is approved by the U.S. Food and Drug Administration for use in pregnancy and is category B. Compared to NPH insulin, it improves fasting plasma glucose and decreases hypoglycemic events. There is a strong evidence base to recommend insulin detemir in pregnancy, but the lack of definitive fetal benefit means that there is no pressing need to switch a woman whose diabetes is well controlled by NPH insulin to insulin detemir.

Insulin glargine (Lantus®) was previously a pregnancy category C medication and was ...