Preterm Labor and Newborn

Preterm Labor What is preterm labor?

Regular contractions with cervical effacement or dilation changes, OR regular contractions with cervical dilation of 2 cm, according to the lecture.

What is preterm birth?

Birth between 20 0/7 and 36 6/7 weeks of gestation.

How does the lecture classify preterm birth by gestational age?

Very preterm: before 32 weeks. Moderately preterm: approximately 32–34 weeks. Late preterm: approximately 34–36 weeks.

How does preterm birth differ from low birth weight?

Preterm birth describes gestational age below 37 weeks. Low birth weight describes weight at birth. A term infant may have low birth weight because of growth restriction.

Why is gestational age important beyond birthweight?

Gestational age reflects organ maturity. A heavier infant can still have immature body systems if born early.

What does the pregnancy-growth infographic emphasize at 35, 37, and 39 weeks?

At 35 weeks, the brain needs more time to develop. At 37 weeks, the brain, lungs, and liver are still developing. In a healthy pregnancy without an indication for earlier delivery, the infographic encourages waiting until at least 39 weeks.

What practice changes are associated with reduced preterm birth rates in the lecture?

Fewer high-order multiple pregnancies from fertility treatment, fewer scheduled late-preterm or near-term births, improved recurrent-preterm-birth prevention, and declining teen birth rates.

What is the strongest historical risk factor for spontaneous preterm birth?

A previous spontaneous preterm birth. Box 17.1 specifically lists a previous birth between 16 and 36 weeks.

What infection-related and structural factors increase spontaneous preterm labor risk?

Genital tract colonization, infection or instrumentation, periodontal disease, uterine anomalies, and unexplained pregnancy bleeding.

What pregnancy and weight factors increase spontaneous preterm labor risk?

Assisted reproduction, multifetal pregnancy, prepregnancy underweight with BMI below 19.6, and obesity with BMI above 30.

What behavioral and social factors are associated with preterm birth?

Smoking, substance use, high stress, limited education or income, and late or absent prenatal care.

What additional factors appear in the preterm-birth infographic?

Teenage pregnancy, age over 35, prior preterm birth, infection, multiple gestation, low income, tobacco, substance use, and stress. Black race is listed as a population disparity, rather than an individual biological cause.

What factors does the newborn lecture add to preterm-birth risk assessment?

Environmental exposures such as toxic chemicals, radiation, teratogens, certain medications, and illicit drugs; maternal age or parity extremes; maternal infection; fetal anemia; and nonreassuring fetal heart rate patterns.

What causes spontaneous preterm labor?

Causes are multifactorial. The lecture emphasizes infection and also identifies uterine or cervical structural abnormalities, bleeding at the placental implantation site, and decreased progesterone.

What is indicated preterm birth?

Planned early delivery because a maternal or fetal condition makes continuing pregnancy unsafe. The lecture states approximately 25% of U.S. preterm births are indicated.

What maternal and obstetric conditions may indicate preterm birth?

Diabetes, chronic hypertension, preeclampsia, placental abruption or previa, cholestasis, and a previous vertical or T-shaped uterine incision.

What additional maternal disorders appear in the indicated-birth textbook box?

Seizures, thromboembolism, connective tissue disorders, asthma or chronic bronchitis, maternal HIV or active herpes, obesity, smoking, and advanced maternal age.

What fetal conditions may indicate preterm birth?

Poor growth, abnormal NST or BPP, polyhydramnios or oligohydramnios, hydrops, ascites, blood group alloimmunization, birth defects, and multifetal complications such as twin-to-twin transfusion.

What cervical length finding makes preterm birth less likely in the lecture?

Cervical length greater than 30 mm.

What is fetal fibronectin?

A glycoprotein that acts like adhesive between fetal and maternal tissues. Its presence during the late second or early third trimester may be associated with inflammation or disruption.

Why is a negative fetal fibronectin result especially useful?

Its negative predictive value is high. The lecture states a negative result is associated with less than a 1% chance of delivery within two weeks.

What discharge changes may indicate preterm labor?

Increased discharge or a change to watery, mucus-like, or bloody discharge.

What pain or pressure symptoms may indicate preterm labor?

Pelvic or lower abdominal pressure, a constant low dull backache, and mild abdominal cramps with or without diarrhea.

Do preterm contractions have to be painful?

No. Regular or frequent uterine tightening may be painless. Ruptured membranes are another warning sign.

Does a patient need every warning sign to have preterm labor?

No. The textbook box states a patient may have only one sign or several.

What self-care steps are listed in the lecture’s preterm-labor teaching box?

Stop activity, lie on the side, drink 2–3 glasses of water or juice, and reassess after one hour. The box advises contacting the provider for worsening or recurring symptoms. Suspected fluid leakage, bleeding, or decreased fetal movement warrants prompt contact.

What early interventions are listed for recognized preterm labor?

Transfer to a higher level of care, antibiotics when indicated, antenatal corticosteroids, and magnesium sulfate before 32 weeks for fetal neuroprotection.

What prevention and lifestyle measures appear in the lecture?

Address risk factors, teach warning signs, and provide home-care education. The slides also list progesterone injections and activity or sexual restrictions; these are older lecture recommendations.

What is the purpose of tocolytic therapy?

Suppress uterine contractions to delay birth. The lecture states the listed drugs are not FDA approved specifically for this use and do not reduce the overall preterm birth rate.

How does terbutaline work, and what major caution is listed?

It is a beta-adrenergic agonist that relaxes smooth muscle, suppressing uterine activity and causing bronchodilation. Avoid it in patients with known or suspected heart disease.

How does indomethacin work, and what gestational limit is listed?

It inhibits prostaglandin synthesis to relax uterine smooth muscle. The lecture limits use to gestational age below 32 weeks.

How does nifedipine suppress contractions?

It blocks calcium entry into smooth muscle cells, relaxing the uterus. The lecture cautions against concurrent use with other tocolytics.

Why is magnesium sulfate administered before 32 weeks in threatened preterm birth?

For fetal neuroprotection. This purpose differs from the fetal lung maturation provided by corticosteroids.

How does the lecture describe magnesium sulfate’s action?

It is a CNS depressant that also relaxes smooth muscle, including uterine muscle.

Why are antenatal betamethasone or dexamethasone given?

To accelerate fetal lung maturation and surfactant production, reducing the severity of neonatal respiratory distress syndrome.

What additional benefits are listed for antenatal corticosteroids?

Reduced likelihood of intraventricular hemorrhage, necrotizing enterocolitis, and neonatal death. They also promote maturation of other organs.

What gestational range is listed in the embedded corticosteroid guide?

24–34 weeks. The guide identifies this obstetric use as off label.

What is the betamethasone regimen in the medication guide?

12 mg IM for two doses, 24 hours apart.

What is the dexamethasone regimen in the medication guide?

6 mg IM for four doses, 12 hours apart.

How do tocolytics, corticosteroids, and magnesium differ?

Tocolytics suppress contractions. Corticosteroids promote fetal maturation. Magnesium before 32 weeks provides fetal neuroprotection.

What is PROM?

Prelabor rupture of membranes: spontaneous rupture and leakage of amniotic fluid before labor begins, at any gestational age.

What is PPROM?

Preterm prelabor rupture of membranes: rupture before labor and before 37 0/7 weeks.

What history and cervical findings increase PPROM risk?

Previous preterm PROM and cervical length below 25 mm on transvaginal ultrasound.

What additional PPROM risks appear in Box 17.6?

Second- or third-trimester bleeding, low socioeconomic status, BMI below 19.8, smoking, and illicit drug use.

What is the most common complication of PROM or PPROM emphasized in the lecture?

Chorioamnionitis.

What competing concerns guide PPROM management?

The benefits of additional fetal maturation versus the risk of infection from prolonged membrane rupture.

How does the lecture summarize management after membrane rupture by gestational age?

At term: delivery, with induction if necessary. At 32–36 weeks: immediate birth versus expectant management. Below 32 weeks: conservative management with steroids, antibiotics, and magnesium as indicated.

What is chorioamnionitis?

Bacterial infection of the amniotic cavity.

What clinical findings suggest chorioamnionitis?

Maternal fever, maternal and fetal tachycardia, uterine tenderness, and foul-smelling amniotic fluid.

What increases chorioamnionitis risk?

Long labor, prolonged membrane rupture, multiple vaginal examinations, and internal monitoring.

What maternal complications can result from chorioamnionitis?

Bacteremia, sepsis, dysfunctional labor, cesarean birth, wound infection, and pelvic abscess.

What newborn complications can result from chorioamnionitis?

Pneumonia, bacteremia, sepsis, respiratory distress, and cerebral palsy associated with fetal inflammatory response syndrome.

How is chorioamnionitis treated?

Broad-spectrum IV antibiotics and delivery.

What does the preterm-labor professor emphasize for the exam?

Definitions, textbook boxes, PROM versus PPROM, tocolytic risks and benefits, chorioamnionitis complications, and the different purposes of magnesium and betamethasone. The Preterm Newborn Why are preterm infants vulnerable during transition after birth?

What does the birthweight and gestational-age chart demonstrate?

Mortality generally decreases as gestational age and birthweight increase. Its historical bands range from greater than 50% to less than 4%; they are course illustrations rather than individual survival predictions.

What are the newborn lecture’s birthweight classifications?

LBW: below 2,500 g. VLBW: below 1,500 g. ELBW: below 1,000 g.

Why should the gram cutoffs be used when studying birthweight?

Some pound-and-ounce equivalents in the slides are inconsistent. For reference, 2,500 g is approximately 5 lb 8 oz.

How does the growth chart distinguish SGA, AGA, and LGA?

SGA is at or below approximately the 10th percentile, AGA is between the 10th and 90th percentiles, and LGA is above the 90th percentile for gestational age.

How do symmetric and asymmetric IUGR differ?

Symmetric: head size, length, and weight are all below the 10th percentile. Asymmetric: weight is below the 10th percentile while head size and length are relatively preserved.

Why may asymmetric IUGR have a better developmental outlook?

It reflects compromise later in pregnancy with relative brain sparing, increasing the chance of normal growth and development.

What factors may explain an infant being small for gestational age?

Small parental size or genetics, as well as growth-affecting conditions such as infection, teratogen exposure, or chromosomal abnormalities.

What maternal and placental factors increase IUGR risk?

Preeclampsia, placental problems, asthma, hypertension, and smoking.

How does placental insufficiency cause complications in growth-restricted infants?

Reduced oxygen delivery causes chronic hypoxia and asphyxia risk. Chronic hypoxia increases RBC production, leading to polycythemia and later hyperbilirubinemia.

Why are growth-restricted infants vulnerable to hypothermia and hypoglycemia?

They have less brown fat and relatively greater surface area. Heat loss increases metabolic demand and glucose use.

What respiratory immaturity occurs in preterm infants?

Fewer functional alveoli, fragile pulmonary capillaries, weak or absent gag reflexes, irregular breathing, and inadequate surfactant.

Why does a weak gag reflex increase respiratory risk?

It increases the chance of aspirating secretions.

What does inadequate surfactant do to the lungs?

It promotes alveolar collapse, or atelectasis, and increases the pressure needed to expand the lungs.

What gestational age is associated with insufficient surfactant in the lecture?

Surfactant may be inadequate before approximately 34 weeks.

How does surfactant deficiency produce RDS?

Alveolar collapse impairs gas exchange, causing hypoxemia, carbon dioxide retention, and acidosis.

What risk factors for RDS are listed?

Prematurity, perinatal asphyxia, maternal type 1 or type 2 diabetes, cesarean without labor, male sex, and White race as a lecture-listed population association.

What chest radiograph appearance is associated with RDS?

A ground-glass appearance.

What breathing signs suggest neonatal respiratory distress?

Retractions, seesaw breathing, tachypnea, grunting, nasal flaring, and apnea.

What additional respiratory-distress findings appear in the infographic?

RR above 60/min, HR above 160/min, cyanosis, and suprasternal, intercostal, or subcostal retractions.

What oxygenation findings are listed with RDS?

Central cyanosis and PaO₂ below 60 mmHg.

How does the lecture define apnea?

No spontaneous breathing for more than 20 seconds, usually associated with bradycardia. It differs from periodic breathing.

What is the first intervention listed for apnea and bradycardia?

Gentle tactile stimulation while assessing the infant.

What care is needed if an infant does not respond to tactile stimulation?

Provide respiratory support, including PPV when breathing is absent or ineffective, according to neonatal protocols. Continue heart rate and respiratory monitoring.

What other problems should be considered if the infant does not respond to oxygen?

The lecture identifies hypovolemic shock and congenital cardiac defects as possibilities.

What respiratory support methods are listed for preterm infants?

CPAP, oxygen by hood or nasal cannula, mechanical ventilation, and high-frequency ventilation.

What does administered surfactant accomplish?

Improves lung compliance and oxygen–carbon dioxide exchange.

What additional respiratory therapies are listed?

Nitric oxide and extracorporeal membrane oxygenation; the lecture lists ECMO for infants above 34 weeks.

What assessments support care for impaired gas exchange?

Blood gases, acid–base balance, oxygen saturation, respiratory rate and pattern, breath sounds, airway patency, and signs of increased work of breathing.

What positioning guidance is listed for respiratory care?

Avoid neck hyperextension. The lecture includes prone or supine positioning in monitored care; home sleep positioning is supine.

Why do preterm infants lose heat easily?

Low brown fat, low glycogen and subcutaneous fat stores, limited heat production, low tone with extended posture, and a large surface area relative to weight.

What skin finding is illustrated with hypothermia?

Mottling.

What nursing interventions help prevent hypothermia?

A neutral thermal environment, prewarmed radiant warmer or servo-controlled incubator, appropriate swaddling and hat, and skin-to-skin when tolerated.

What cold exposures should be avoided?

Drafts, cool air, cold scales, cold stethoscopes, cold examination surfaces, and prolonged bathing.

What benefits of skin-to-skin care are listed beyond warmth?

Improved parent–infant bonding, decreased respiratory distress, and increased breast milk production.

What feeding methods may be used for preterm infants?

Oral feeding, gavage feeding, or parenteral nutrition. Enteral feeding may not always be possible.

What nourishment options are listed?

The parent’s human milk, donor human milk, and infant formula.

What nutritional and fluid assessments are important?

Weight, fluid balance, insensible water loss, elimination patterns, and strict intake and output.

What nonfeeding sucking intervention appears in the nutrition lecture?

Nonnutritive sucking.

What is necrotizing enterocolitis?

An inflammatory disease involving injured gastrointestinal mucosa.

Why is hypoxia a major NEC risk?

Blood is preferentially directed to the heart and brain, reducing intestinal perfusion and causing gut ischemia.

What perfusion and cardiopulmonary conditions increase NEC risk?

Asphyxia, hypoxia, RDS, hypovolemia, shock, PDA, congenital heart disease, and polycythemia.

What additional NEC risks are listed?

Umbilical artery catheterization, exchange transfusion, early enteral formula feeding, GI infection, and cocaine exposure.

What gastrointestinal findings may suggest NEC?

Abdominal distention, discoloration, pain, and residual gastric aspirate.

What systemic findings may suggest NEC?

Decreased activity, temperature instability, pallor or mottling, recurrent apnea and bradycardia, metabolic acidosis, and respiratory distress.

What nursing assessments are emphasized for NEC?

Measure abdominal girth, inspect for visible bowel loops, assess abdominal pain, and evaluate emesis and stools for green bile or blood.

What feeding approach is associated with lower NEC risk?

Breastfeeding or expressed parent or donor human milk.