Chapter 15: Pre-Existing Conditions in Pregnancy

Pre-Existing Conditions in Pregnancy lesson examines the complexities of managing chronic health conditions during the prenatal, intrapartum, and postpartum periods, emphasizing the collaborative role of the interprofessional healthcare team in optimizing outcomes for both the parent and the fetus. A significant portion of the material is dedicated to metabolic disorders, particularly pregestational diabetes, where normal physiological shifts like increased insulin resistance in the later trimesters require precise glycemic control to avoid complications such as fetal macrosomia, ketoacidosis, and congenital anomalies. We explore the fluctuating insulin needs from conception through lactation and the vital role of preconception counseling to stabilize vascular complications and establish a healthy A1C. The discussion extends to thyroid dysfunction, contrasting the management of hyperthyroidism with propylthiouracil or methimazole against the hormone replacement therapy required for hypothyroidism to prevent impaired neurological development in the fetus. Cardiovascular health is another critical focus, as the natural expansion of blood volume during pregnancy can lead to cardiac decompensation in patients with congenital or acquired heart diseases; we categorize these risks using the New York Heart Association functional classification and outline specific protocols for conditions like mitral valve stenosis, peripartum cardiomyopathy, and Marfan syndrome. The rising prevalence of obesity is addressed, highlighting its link to gestational hypertension, the need for specialized equipment, and the increased risk of stillbirth. Hematological issues, including various forms of anemia such as iron deficiency, sickle cell disease, and thalassemia, are reviewed regarding their impact on oxygen-carrying capacity and the risk of preterm birth. Respiratory management focuses on maintaining oxygenation in patients with asthma or cystic fibrosis, while neurological considerations involve balancing seizure control in epilepsy against the potential for birth defects caused by certain anticonvulsant medications. Autoimmune conditions like systemic lupus erythematosus and myasthenia gravis are analyzed for their unpredictable courses and the necessity of monitoring for flares and neonatal passive immunity issues. Furthermore, the care of patients with spinal cord injuries involves preventing life-threatening autonomic dysreflexia during labor, while HIV management centers on the strict use of antiretroviral therapy and the avoidance of breastfeeding to minimize perinatal transmission. Finally, the material advocates for a trauma-informed, harm-reduction approach when supporting pregnant individuals experiencing substance use, emphasizing stabilization and community resources over stigmatization to ensure a safe environment for the growing family.