3.1 Perinatal Risk Factors

Why Risk Assessment Matters Before Birth

Approximately 10% of newborns need some assistance to begin breathing at birth, and about 1% require extensive resuscitation measures such as intensive positive-pressure ventilation, intubation, chest compressions, or medications. Those numbers are small in absolute terms, but they are large enough that no delivery room can safely treat newborn transition as an afterthought. The Neonatal Resuscitation Program (NRP) therefore places anticipation and preparation at the front of the algorithm: skilled people and working equipment must already be in the room when the baby arrives.

Risk-factor assessment is not fortune-telling. Many high-risk deliveries produce vigorous infants who need only routine care, and occasional low-risk term births still require urgent ventilation. The clinical purpose of listing risks is practical: risk changes who must attend and what equipment is staged and checked. A scheduled, low-risk term vaginal birth still needs a qualified newborn attendant and a ready warmer and bag-mask (or T-piece) setup. A 26-week twin delivery with Category III tracing and meconium needs a full resuscitation team, preterm-specific thermal protection, and advanced airway and medication capability standing by.

Think of perinatal risk as a staffing and logistics signal, not a guarantee of outcome. On the NRP exam and in real practice, the correct mental model is: identify risk → match personnel and supplies → brief the team → reassess if conditions change.

Maternal (Antepartum) Risk Factors

Maternal conditions that impair placental gas exchange, increase preterm birth risk, or signal systemic illness raise the probability that the newborn will need help. High-yield maternal factors include:

1. Hypertensive disorders of pregnancy, including chronic hypertension, gestational hypertension, preeclampsia, and eclampsia. Reduced placental perfusion can produce growth restriction, abruption risk, and a stressed fetus that tolerates labor poorly.
2. Diabetes mellitus (pregestational or gestational). Infants of diabetic mothers may be large for gestational age with birth trauma risk, or they may have delayed lung maturity and polycythemia/hypoglycemia risk after birth. Either pattern can complicate transition.
3. Maternal infection and signs of intra-amniotic infection (fever, maternal tachycardia, uterine tenderness, foul fluid). Fetal inflammatory response and early-onset sepsis risk increase the chance of depression, respiratory distress, and need for support.
4. No or limited prenatal care. Unknown dating, unrecognized anomalies, untreated infections, and unmanaged medical disease all degrade the quality of the pre-birth plan.
5. Substance use (opioids, stimulants, alcohol, and others). Neonatal respiratory depression, withdrawal physiology later, and associated social/medical complexity can appear; opioid exposure especially can contribute to poor tone and respiratory effort at birth if recent maternal dosing occurred.
6. Other classic antepartum flags: previous fetal or neonatal death, significant anemia, oligohydramnios or polyhydramnios, placenta previa or known abruption risk, maternal age extremes in some contexts, and major maternal cardiorespiratory disease.

When you hear these on handoff, translate them into action. Maternal diabetes plus macrosomia should make you think about shoulder dystocia readiness and a second skilled person. Severe preeclampsia with growth restriction should make you think about possible preterm physiology, thermal vulnerability, and a depressed infant after operative delivery.

Fetal Risk Factors

Fetal factors describe the baby’s intrinsic vulnerability:

• Prematurity is the single most powerful predictor of needing support. Preterm lungs, weak respiratory drive, thin skin, and immature thermal control make warming, airway positioning, and careful ventilation especially important.
• Intrauterine growth restriction (IUGR) or small-for-gestational-age status often reflects chronic placental insufficiency. These infants may tolerate labor poorly and can present with low reserves, polycythemia, or hypoglycemia risk after birth.
• Known congenital anomalies (airway malformations, congenital diaphragmatic hernia, abdominal wall defects, complex heart disease, hydrops) demand anomaly-specific equipment and specialists, not a generic one-person plan.
• Multiple gestation multiplies the problem: more babies, higher preterm rates, higher malpresentation rates, and the possibility that two resuscitations occur at once. Multiples are a staffing problem as much as a medical one.
• Other fetal flags: hydrops, decreased fetal movement, non-reassuring antenatal testing, and known fetal anemia or twin-twin transfusion physiology.

Fetal risk should change both who is called (neonatology, respiratory therapy, pediatric surgery when relevant) and what is opened (smaller masks and endotracheal tubes, plastic wrap, temperature probe, surfactant pathway readiness in very preterm births).

Intrapartum Risk Factors

Intrapartum events can convert a previously “routine” birth into a high-risk resuscitation within minutes. NRP expects you to recognize these as prompts to add people and recheck equipment, not merely to document them later:

• Category II or Category III fetal heart-rate tracing — ongoing concern for fetal hypoxia or acidemia.
• Meconium-stained amniotic fluid — marker of fetal stress; management of the baby still follows vigor-based assessment (routine tracheal suctioning of non-vigorous meconium-stained newborns is not the default), but personnel readiness increases.
• Prolonged rupture of membranes and chorioamnionitis — infection/inflammation risk and possible neonatal depression or early sepsis physiology.
• Emergency cesarean delivery — compressed timeline, possible general anesthesia effects, and higher chance of a non-vigorous infant.
• Shoulder dystocia — birth trauma, asphyxia risk, and need for immediate airway/breathing support after delivery of the body.
• Breech presentation and other malpresentations — higher trauma and asphyxia risk, especially if extraction is difficult.
• Forceps or vacuum-assisted delivery — instrumented vaginal birth associated with higher rates of need for resuscitation compared with uncomplicated spontaneous birth.
• Other high-yield intrapartum events: cord prolapse, significant antepartum hemorrhage/abruption, maternal general anesthesia, uterine rupture, and prolonged second stage with progressive tracing deterioration.

Matching Risk to People: Minimum vs Escalated Teams

NRP’s staffing rule has two layers.

Layer 1 — every birth: At least one qualified person whose only responsibility is the newborn and who can initiate resuscitation, including positive-pressure ventilation. Advanced help must be immediately available. A nurse who is primarily managing the mother does not satisfy this requirement if the baby needs simultaneous focused care.

Layer 2 — anticipated high-risk birth: Assemble additional skilled team members before delivery. Ideal composition includes people who can manage airway/PPV, chest compressions and monitoring, vascular access and medications, and documentation/timekeeping, with a clear team leader. Presence of risk does not mean an automatic “full code team for every listed factor” in a mechanical sense—clinical judgment still scales the response—but high-risk anticipation should never default to a lone attendant hoping someone wanders in after the baby is born.

Exam trap: confusing “risk present” with “resuscitation guaranteed,” or the opposite error—treating risk lists as optional paperwork. Correct answer pattern: risk informs preparation and team size; it does not replace ongoing assessment of the baby after birth.