ABOG Maternal-Fetal Medicine key terms

A hypertensive disorder of pregnancy with new-onset blood pressure of at least 160/110 mm Hg, or elevated liver enzymes, low platelets, renal insufficiency, pulmonary edema, or visual or cerebral symptoms, indicating risk of maternal organ injury.

A variant of severe preeclampsia defined by hemolysis, elevated liver enzymes, and low platelet count, which can cause hepatic rupture and requires prompt delivery and blood product support.

Glucose intolerance first recognized during pregnancy, diagnosed by a two-step or one-step oral glucose tolerance test, and managed with diet, exercise, and insulin or oral agents to reduce macrosomia and hypertensive complications.

Heart failure with reduced ejection fraction presenting in late pregnancy or the months after delivery in a person without prior cardiac disease, requiring standard heart failure therapy and delivery planning.

The product of heart rate and stroke volume, which rises substantially in pregnancy and falls during labor and after delivery, so that fluid shifts and anesthesia can destabilize patients with cardiac disease.

Fluid accumulation in the lungs from cardiogenic causes, preeclampsia, tocolytics, or fluid overload, presenting with dyspnea, hypoxemia, and crackles and requiring oxygen, diuresis, and treatment of the underlying cause.

Widespread activation of coagulation that consumes platelets and clotting factors, causing bleeding and thrombosis, often triggered by placental abruption, amniotic fluid embolism, or severe infection.

A rare, sudden obstetric emergency in which amniotic fluid enters the maternal circulation, causing hypotension, hypoxemia, coagulopathy, and seizures, managed with supportive critical care and rapid delivery.

Administration of magnesium sulfate to patients at risk of preterm birth before 32 weeks to reduce the risk of cerebral palsy in the offspring, given as a bolus followed by infusion.

Betamethasone or dexamethasone given to patients at risk of preterm delivery between roughly 24 and 34 weeks to accelerate fetal lung maturation and reduce neonatal respiratory distress, intraventricular hemorrhage, and mortality.

Use of medications such as nifedipine or indomethacin to temporarily inhibit uterine contractions and allow time for corticosteroids or transfer, without reliably prolonging pregnancy long term.

Delivery before 37 completed weeks of gestation, classified by gestational age and cause, and the leading contributor to neonatal morbidity and mortality worldwide.

A suture placed around the cervix to reinforce it in patients with cervical insufficiency or a history of mid-trimester loss, with cerclage types including history-indicated, ultrasound-indicated, and emergency placement.

Transvaginal ultrasound measurement of the closed cervix used to estimate preterm birth risk and guide interventions such as cerclage or progesterone in patients with a shortened cervix.

Failure of a fetus to reach its growth potential, often defined by estimated fetal weight below the 10th percentile or by abnormal umbilical artery Doppler findings, and associated with stillbirth and neonatal complications.

Doppler ultrasound assessment of umbilical artery blood flow, where absent or reversed end-diastolic flow signals placental insufficiency and guides timing of delivery in growth-restricted fetuses.

A fetal assessment combining nonstress testing with ultrasound evaluation of fetal breathing, movement, tone, and amniotic fluid volume, each scored, to identify fetuses at risk of acidemia.

A fetal heart rate monitoring test that is reactive when accelerations meet gestational-age criteria, indicating an intact fetal autonomic nervous system and adequate oxygenation.

A tracing with absent baseline variability plus recurrent late decelerations, recurrent variable decelerations, bradycardia, or a sinusoidal pattern, requiring immediate evaluation and often expedited delivery.

More than five contractions in ten minutes averaged over 30 minutes, which can impair fetal oxygenation and often requires reducing or stopping uterotonic agents and repositioning the patient.

Failure to deliver the fetal shoulders after the head with routine traction, managed with maneuvers such as McRoberts and suprapubic pressure, and associated with brachial plexus injury and neonatal depression.

Excessive fetal size, commonly defined as estimated or actual birth weight above 4,000 to 4,500 grams, increasing the risk of shoulder dystocia, operative delivery, and neonatal hypoglycemia.

Cumulative blood loss of at least 1,000 mL or bleeding with hemodynamic instability after delivery, most often from uterine atony and managed with uterotonics, tranexamic acid, and escalation to surgery.

An intrauterine balloon catheter inflated to apply pressure to the uterine cavity and control atony-related postpartum hemorrhage when uterotonics alone fail.

A sonographic estimate calculated from head, abdominal, and femur measurements, with accuracy limited by gestational age and fetal position, used to guide growth assessment and delivery planning.

A maternal blood test that analyzes placental DNA fragments to screen for trisomies 21, 18, and 13 and sex chromosome differences, with high sensitivity but a positive result requiring diagnostic confirmation.

Prenatal diagnostic procedure that samples placental villi, typically between 10 and 13 weeks, for karyotype, microarray, or molecular testing, with a small procedure-related pregnancy loss risk.

Prenatal diagnostic procedure that aspirates amniotic fluid, usually after 15 weeks, for fetal karyotype, microarray, or infection testing, with a small procedure-related pregnancy loss risk.

A genomic test that detects submicroscopic deletions and duplications across the genome, offering higher diagnostic yield than karyotype in fetuses with structural anomalies.

Use of maternal serum markers, ultrasound markers, or cell-free DNA to estimate fetal trisomy risk, distinguishing screening tests from diagnostic tests that establish a diagnosis.

The sonographic measurement of fluid behind the fetal neck between 11 and 14 weeks, increased in trisomies, congenital heart disease, and genetic syndromes, and used in first-trimester risk assessment.

Intrapartum penicillin or ampicillin given to carriers of group B Streptococcus to prevent early-onset neonatal sepsis, guided by culture screening at 36 to 37 weeks or risk-based indications.

Intraamniotic infection presenting with maternal fever plus uterine tenderness, foul discharge, or fetal tachycardia, treated with broad-spectrum antibiotics and delivery, and a risk factor for neonatal sepsis.

Rupture of membranes before 37 weeks and before labor onset, managed with antibiotics, corticosteroids, and expectant monitoring for infection and abruption, with delivery timed by gestational age and fetal status.

The most common congenital viral infection, often asymptomatic in the mother but capable of causing fetal hearing loss, microcephaly, and neurodevelopmental impairment after primary maternal infection.

A group of infections including toxoplasmosis, other agents, rubella, cytomegalovirus, and herpes simplex that can cross the placenta and cause congenital anomalies, growth restriction, and neurologic injury.

A mosquito-borne flavivirus infection that can cause fetal microcephaly and brain anomalies, prompting avoidance of endemic travel and serial fetal imaging after maternal exposure.

A coordinated team response to maternal cardiac arrest that includes left uterine displacement, continuous high-quality CPR, airway management, and perimortem cesarean delivery within about four minutes if resuscitation fails.

Cesarean delivery performed during maternal cardiac arrest, ideally within four minutes of arrest, to relieve aortocaval compression and improve the chance of maternal and neonatal survival.

Labor pain relief delivered through an epidural or combined spinal-epidural technique, with risks including hypotension, inadequate block, and rarely epidural hematoma or infection.

Injection of the patient's own blood into the epidural space to seal a dural puncture and relieve postdural puncture headache after neuraxial procedures.

Neurologic and cardiac toxicity from local anesthetic absorbed into the circulation, presenting with seizures or arrhythmia and treated with lipid emulsion rescue in addition to standard resuscitation.

The reciprocal of the absolute risk reduction, expressing how many patients must receive an intervention for one additional patient to benefit.

The arithmetic difference in event rates between control and treatment groups, which conveys the actual magnitude of benefit unlike a relative risk reduction.

A range of values that plausibly contains the true effect estimate, with width reflecting precision and a range crossing the null value indicating a statistically non-significant result.

The process of disclosing material risks, benefits, and alternatives to a patient with decision-making capacity and obtaining voluntary agreement before a procedure or treatment.

A collaborative process in which the clinician presents evidence and the patient's values guide the choice, exemplified by counseling about mode of delivery after prior cesarean.

A patient safety framework that distinguishes human error from at-risk or reckless behavior, encouraging error reporting while holding individuals accountable for intentional unsafe acts.

A structured, non-punitive review of severe maternal events and deaths to identify system failures and implement changes that improve obstetric care.

Unexpected outcomes of labor and delivery that cause significant short- or long-term health consequences, such as transfusion, hysterectomy, or organ failure, tracked as a quality measure.

Planned vaginal delivery attempt after a prior cesarean, requiring counseling about the chance of success and the risk of uterine rupture, with continuous monitoring during labor.

A full-thickness tear of the uterine wall, often at a prior cesarean scar, presenting with fetal bradycardia, loss of station, or abdominal pain and requiring immediate cesarean delivery.