Preexisting Conditions of the Pregnant Person Placing the Delivery at Risk

Core Concepts

Pregnancy as a stress test

By the third trimester the cardiovascular system is working at much higher output: blood volume expands substantially and cardiac output rises to supply the placenta and growing fetus. The placenta produces hormones that raise insulin resistance, so the pancreas must secrete more insulin to keep glucose normal. Oxygen demand rises with fetal needs. Any preexisting condition that reduces the body's reserve — a stiff heart valve, damaged kidneys, chronic lung disease — has less room to absorb these changes, which is why previously "quiet" conditions can surface or worsen in pregnancy. This is why the nurse must know not just the diagnosis, but how well the condition was controlled before pregnancy.

Cardiac disease

Cardiac conditions (congenital heart defects, valvular disease, cardiomyopathy, arrhythmias) are a leading category of serious pregnancy risk because the heart must sustain a large increase in workload. During labor, each contraction shifts blood back toward the heart, and pushing adds strain. Nursing priorities are conceptual: know the client's baseline and warning symptoms, position for comfort and cardiac workload, monitor closely for shortness of breath, chest pain, or rapid decompensation, and communicate immediately with the obstetric and cardiac teams. Management is highly individualized — the safe plan for one cardiac condition is wrong for another — so institutional protocols and specialist input govern care. (Flag for SME review: specific cardiac conditions carry condition-specific guidelines.)

Pre-gestational diabetes

Diabetes present before pregnancy (as opposed to gestational diabetes arising in pregnancy) exposes the fetus to high glucose from conception onward. Because fetal insulin rises in response, the fetus grows large (macrosomia), which raises the risks of cephalopelvic disproportion, shoulder dystocia, and cesarean birth. The pregnant person faces higher rates of hypertensive disorders, and the newborn is at risk for hypoglycemia after birth when the placental glucose supply is suddenly cut off. In labor the nurse monitors glucose, fetal status, and progress — and prepares for a larger newborn and a neonatal team at birth. Timing of birth (induction or planned cesarean) is usually decided collaboratively based on glucose control, fetal size, and overall status.

Chronic hypertension

Chronic hypertension (elevated blood pressure before pregnancy or early in it) increases the risk of superimposed preeclampsia — preeclampsia on top of existing hypertension — and of placental insufficiency, which can restrict fetal growth. In labor the nurse watches blood pressure trends, fetal heart rate patterns, and any new signs of preeclampsia (see the monitoring topic in this chapter). Some blood pressure medications are continued in pregnancy and some are changed, so the nurse verifies the current medication list against the plan rather than assuming.

Obesity

Obesity affects nearly every step of the birth process: fetal size, labor progress, venous access, anesthesia dosing and placement, cesarean rates, wound healing, and postpartum recovery. Positioning in labor and surgery takes planning, and equipment must fit the client. The nurse's role is dignified, individualized care: more difficult monitoring and IV access are nursing challenges to solve, not reasons to treat the client differently.

Asthma and pulmonary disease

Asthma may be stable before pregnancy but worsen with the respiratory changes of pregnancy, and an asthma exacerbation during labor threatens fetal oxygenation directly — when the pregnant person can't get oxygen, neither can the fetus. Clients usually continue their asthma medications in pregnancy (with provider direction), and the nurse watches respiratory effort, oxygen saturation, and fetal response, alerting the team early at the first sign of wheezing or distress.

Seizure disorders

Seizure disorders require careful medication management throughout pregnancy, because both seizures and some medications carry risks. In labor the nurse must know the client's usual triggers and warning signs, keep the environment safe, and know the unit's plan for a seizure during labor (protect the client, call for help, monitor the fetus). Safety at the bedside — padding the bed, staying with the client — is the immediate nursing concern.

Renal, autoimmune, and hematologic conditions

Chronic kidney disease reduces the body's ability to handle the increased blood flow and waste load of pregnancy and is associated with preterm birth and hypertensive complications. Autoimmune conditions such as systemic lupus erythematosus can flare in pregnancy, sometimes involving the placenta. Hematologic conditions include the anemias (less oxygen-carrying reserve and less tolerance for blood loss) and thrombophilias (increased clotting risk). These conditions all share one lesson: the labor nurse must know the baseline, know the target for this specific client, and report deviations promptly rather than relying on memory of "normal" values.

Infectious diseases: HIV and hepatitis B

HIV is managed in pregnancy to suppress the viral load, which dramatically reduces the chance of passing the virus to the fetus during labor and birth. The labor plan — including whether the mode of birth is vaginal or cesarean and how the newborn is protected — depends on the person's viral load and other factors, and follows current guidelines. Hepatitis B is transmitted at birth primarily through blood exposure; newborn immunization/prophylaxis programs are the cornerstone of prevention. Nursing care includes administering ordered care, protecting confidentiality, and supporting the client without stigma.

Substance use and mental health conditions

Substance-use disorders and mental health conditions affect labor in complex ways: withdrawal can be dangerous for both the pregnant person and the newborn, some substances cross the placenta, and the newborn may need specialized monitoring after birth. Fear of judgment is a real barrier to care, so the nurse's job includes building trust, coordinating with social work and addiction specialists, and treating the client with the same respect as anyone else on the unit. Opioid and other substance-use care plans are highly protocolized and institution-specific — never improvise.

Collaborative care and birth planning

Because these clients have complex needs, care is a team sport: obstetricians, maternal-fetal medicine, anesthesia, cardiology or other specialists, neonatal providers, pharmacists, social workers, and nurses. Preconception counseling (optimizing the condition before pregnancy) is the ideal starting point, and the birth plan should be written before labor starts: mode of birth, monitoring, medications, anesthesia preferences, newborn plan, and who to call. The labor nurse is often the one who executes that plan at 3 a.m., so the plan must be documented, current, and understood.

Common Confusions