PRETERM LABOR Flashcards
Sub-categories of preterm birth, based on gestational age
- Extremely preterm : less than 28 weeks
- Very Preterm : 28-32 weeks
- Moderate to late preterm : 32-36 6/7 weeks
Refers to <37 weeks AOG but more than 20 completed weeks
Preterm
37-41 weeks AOG
Term
Sub-categories of term birth, based on gestational age:
- Early term (37-38 6/7 weeks)
- Full term (39-40 6/7 weeks)
- Late term (41-41 6/7 weeks)
- Post term (42 & onwards)
Defined as regular contractions resulting to cervical effacement & dilation that occurs before 37 completed weeks but after 20 completed weeks.
Preterm Labor
Risk Factors / Causes
- History of Premature birth
- Smoking & Drug Use
- Short interpregnancy interval
- Previous surgeries involving the cervix
- Congenital abnormalities of the uterus
- Cervical insuffiency
- Infections
- Maternal stress
- Dehydration
- Uterine distention
- Maternal factors
- Placental issues
Strongest risk factor for preterm labor
History of Premature birth
Why is smoking & drug use a risk factor
Vasoconstriction 🡪 decrease uterine / placental perfusion 🡪placental insufficiency
How does infections become a risk factor or a cause for preterm labor
Microbial invasion 🡪 causes inflammation on uterine muscles/weakening of amniotic sac 🡪 triggers release of prostaglandins 🡪 uterine contractions
2 reasons how dehydration is a risk factor / cause?
- Can lead to oligohydramnios 🡪 uterine irritation / fetal stress 🡪 contractions
- Can stimulate release of ADH to retain water 🡪 ADH has similar chemical structure as oxytocin 🡪 mistaken as oxytocin 🡪uterine contractions
How is maternal stress a risk factor / cause
oxytocin levels are high under stressful conditions 🡪 uterine contractions
How uterine distention can lead to premature labor
Excessive uterine stretch can send signals that the uterus is of adequate size & that fetus is already “term” 🡪uterine contractions
Predictors of Preterm Labor
1) Measurement of cervical length via UTZ
2) Fetal Fibronectin test
Cervical length that is a good predictor that woman can go into preterm labor
< 2-2.5 cm
Used to rule out preterm labor -In normal conditions, fFn is found at very low levels in cervico-vaginal secretions
Fetal Fibronectin test
Is a protein that is believed to help keep the amniotic sac “glued” to the lining of the uterus.
Fetal fibronectin
Elevated levels of fibronectin indicates preterm labor by how much.
greater than or equal to 50 ng/mL
A Positive fFN test means?
indicates that the “glue” has been disrupted and the woman is at increased risk of premature birth.
Signs of Preterm Labor
- Pelvic pressure & backache
- Regular uterine contractions
- Abdominal pain or cramps
- Vaginal spotting / light bleeding
- Cervical mucus discharge
- Leaking amniotic fluid from vagina
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of consistency.
- Cervical Mucus Discharge : Thick, sticky or stretchy
- Leaking Amniotic Fluid: Watery, thin, continuous
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of color
- Cervical Mucus Discharge : White, clear, yellowish (may have blood streaks)
- Leaking Amniotic Fluid: Clear, pale yellow
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of odor
- Cervical Mucus Discharge : no strong odor
- Leaking Amniotic Fluid: sweet-smelling
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of amount
- Cervical Mucus Discharge : small amounts
- Leaking Amniotic Fluid: continuous trickle or sudden gush
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of significant
- Cervical Mucus Discharge : normal or early sign of labor
- Leaking Amniotic Fluid: Possible water breaking (PROM/PPROM)
Best preventive measures to avoid preterm birth
Maintaning general health during pregnancy
Actions that can be helpful to prevent recurrence of preterm labor
- Remaining on bed rest except to use the bathroom (CBR w/ TP)
- Drinking 8-10 glasses of fluids daily to maintain hydration
- Avoiding activities that could stimulate labor
- Consulting OB-GYN regarding whether sexual contact should be restricted
- Immediately reporting signs of premature rupture of membranes or vaginal bleeding
- Report signs of urinary tract or vaginal infections
- Have women follow appointments for prenatal care.
What to do if uterine contractions recur?
- Emptying bladder to relieve pressure on uterus
- LLD Position to encourage uterine & placental perfusion
- Drinking 2-3 glasses of fluids to increase hydration
- Contacting HC provider to report the incident & ask for further care measures.
What to do if membranes are still intact
Emergency cerclage
Emergency cerclage is done to stop preterm labor. This may be considered in women whose cervix:
- has dilated to less than 4 cm
- w/o significant uterine contractions
- no heavy bleeding
- no evidence of infections
Are also given for treatment of infection, if present
- given as prophylaxis in case or PPROM
Antibiotics
Admnistered via IM to the mother
- Help accelerate Fetal Lung Maturity
- reduces the risk of serious newborn complications such as Respiratory Distress Syndrome
Antenatal Corticosteroids
Commonly used corticosteroids
Betamethasone and dexamethasone
When does effects begin for corticosteroids
after 24 hrs
Max effects of corticosteroids
2-7 days
Indicates how developed are the lungs of the baby in utero
- happens around 37 weeks of pregnancy
Fetal Lung Maturity
Key Factor of Fetal Lung Maturity
Surfactant
Is a slimy, slipper, gel-like substance which helps prevent the alveoli from collapsing during expiration/exhalation
Surfactant
How does surfactant work during inspiration (inhaling)
The lungs expand, and surfactant helps reduce the effort needed to inflate the alveoli.
How does the surfactant work during expiration (exhalation)?
Prevents the alveoli from collapsing by reducing surface tension. Without surfactat, the alveoli would shrink and stick together, making it difficult for the baby to take the next breath.
Helps determine if a baby’s lungs are mature enough for breathing outside the uterus.
- done on amniotic fluid, collected through amniocentesis
Tests for Fetal Lung Maturity
Tests for Fetal Lung Maturity
1) Lecithin - Sphingomyelin (L/S ratio)
L/S ratio of greater than or equal to 2.1 indicates that?
Lungs are mature
- lower risk of respiratory distress
-
L/S ratio of less than 2.1 indicates?
Lungs are immature
- high risk of respiratory distress syndorme
Preterm delivery is usually considered to be safe
What if woman is already in the active phase of preterm labor & steroids were not given. Surfactant (intratracheal route) is given to the newborn if?
- Extremely preterm (28 weeks AOG)
- Has signs of respiratory distess ( grunting, nasal flaring, retractions, etc)
Surfactant is not given to newborn if?
NB is stable & breathing on his own
- no signs of RDS
Anti-contraction medications or labor suppressants . used to inhibit uterine contractions
Tocolytics
Common tocolytics used
- Nifedipine
- Magnesium Sulfate (MgSO4)
- Indomethacin
First-line of tocolytics used. Also used as an antihypertensive agent in preeclampsia
Nifedipine
Is a calcium antagonist - competes with calcium entering the cells causing uterine muscle relaxation.
- also used to prevent seizures in worsening preeclampsia
Magnesium Sulfate
A prostaglandin synthesis inhibitor
- effective tocolytic but often prescribed with caused because of associated negative fetal outcomes
Indomethacin
Why is Indomethacin prescribed with caution?
Premature closure of the ductus arteriosus
It is a fetal blood vessel that connects the pulmonary artery to the aorta, allowing blood to bypass the lungs while the baby is in the wombs.
Ductus arteriousus
Why give tocolytics as a therapeutic management for preterm labor
- Delays labor by slowing or stopping uterine contractions
- give steroids time to work / take effect
When are tocolytics most effective?
- Generally advised between 24-34 weeks of gestation to delay preterm labor & improve neonatal outcomes
Why is tocolytics not usually recommended before 24 weeks?
- Baby is extremely premature, and survival chances are very low.
Why are tocolytics not given after 34 weeks?
Less beneficial since the baby’s lungs are quite developed, and the risks of keeping the baby inside may outweight the benefits
When is tocolytics not advised?
- < 24 weeks AOG
- < 34 weeks AOG and has:
- (+) Rupture of Membranes
- Maternal Complications
When is tocolytics advised?
- < 34 weeks
- If membranes are still intact
- If no identified maternal complications
- If not in active labor (< 4 cm cervical dilation)
- 4 cm dilation - tocolytics may still be attempted, but success is less likely
Nursing Responsibilities for a patient in preterm labor
1) Monitor Maternal and Fetal Status
2) Administer Medications as Prescribed
3) Provide comfort & emotional support
4) Prevent complications
5) Prepare for possible preterm delivery
Monitor Maternal and Fetal Status
- Uterine contractions & fetal heart rate
- rupture of membranes
- maternal vital signs
- assist with UTZ
Administer medications as prescribed
- Tocolytics
- Corticosteroids
- Antibiotics
- IV hydration
Nurse Olivia is caring for a client in preterm labor at 32 weeks who has been given magnesium sulfate, and her contractions have ceased. If the labor can be delayed for the next 2 days, which medication does Nurse Olivia expect to be prescribed?
A. Butorphanol tartrate (Stadol).
B. Fentanyl (Sublimaze).
C. Sufentanil (Sufenta).
D. Betamethasone (Celestone).
D. Betamethasone (Celestone).
During a prenatal visit, a client in her third trimester expresses concern to Nurse Ellen about frequent constipation. Nurse Ellen advises the client to:
A. Take laxatives regularly.
B. Reduce her fluid consumption.
C. Increase her intake of dietary fiber.
D. Use enemas daily.
C. Increase her intake of dietary fiber.
Nurse Emma is educating a group of expectant mothers about preterm labor. She explains that preterm labor is defined as:
A. Labor that starts after 24 weeks of gestation and before 28 weeks of gestation.
B. Labor that starts after 15 weeks of gestation and before 37 weeks of gestation.
C. Labor that starts after 28 weeks of gestation and before 40 weeks of gestation.
D. Labor that starts after 20 weeks of gestation and before 37 weeks of gestation.
D. Labor that starts after 20 weeks of gestation and before 37 weeks of gestation.
Nurse Emily is reviewing a patient’s prenatal history. Which finding would indicate a genetic risk factor?
A. The patient is 25 years old.
B. The patient has a history of preterm labor at 32 weeks’ gestation.
C. The patient has a child with cystic fibrosis.
D. The patient was exposed to rubella at 36 weeks’ gestation.
C. The patient has a child with cystic fibrosis.
Nurse Taylor is preparing to manage a patient in preterm labor. Which drug is commonly used to manage preterm labor by causing smooth muscle relaxation?
A. Prostaglandin
B. Estrogen
C. Ritodrine
D. Oxytocin
C. Ritodrine
Nurse Kelly is documenting the obstetrical history of a pregnant client who reports, “I had a son born at 38 weeks, a daughter born at 30 weeks, and I lost a baby at around 8 weeks.” How should Nurse Kelly record this history?
A. G3 P2
B. G4 P2
C. G3 P3
D. G4 P3
B. G4 P2
Nurse Harper is caring for a pregnant patient at 34 weeks of gestation who is showing signs of preterm labor. The physician has prescribed Betamethasone, and Nurse Harper understands that the medication is intended to:
A. Encourage the production of surfactant in the fetus.
B. Address any underlying infection.
C. Inhibit uterine contractions.
D. Lower the potential for hypertension.
A. Encourage the production of surfactant in the fetus.
Nurse Taylor is preparing a care plan for a patient admitted with a missed abortion at 29 weeks gestation. The treatment that the patient will most likely receive is:
A. Dinoprostone (Prostin E.).
B. Bromocriptine (Parlodel).
C. Magnesium sulfate.
D. Calcium gluconate.
A. Dinoprostone (Prostin E)
Nurse Grace is assessing a patient who is 28 weeks pregnant and believes she might be in labor. To confirm the diagnosis of preterm labor, Nurse Grace would expect the physical examination to reveal:
A. Irregular uterine contractions with no cervical dilation.
B. Regular uterine contractions without cervical dilation.
C. Painful contractions with cervical dilation.
D. Regular uterine contractions with cervical dilation.
D. Regular uterine contractions with cervical dilation.
Nurse Riley is managing a patient at risk of preterm labor. To prevent the progression of labor, the nurse anticipates the administration of which medications?
A. Magnesium sulfate and terbutaline.
B. Progesterone and estrogen.
C. Dexamethasone and prostaglandin.
D. Prostaglandin and oxytocin.
Nurse Riley is managing a patient at risk of preterm labor. To prevent the progression of labor, the nurse anticipates the administration of which medications?
A. Magnesium sulfate and terbutaline.
B. Progesterone and estrogen.
C. Dexamethasone and prostaglandin.
D. Prostaglandin and oxytocin.
