A charge nurse is teaching a newly licensed nurse about substance use disorders during pregnancy.
Which of the following statements by the newly licensed nurse indicates an understanding of the teaching?

Rationale for correct condition:
Ectopic pregnancy occurs when a fertilized ovum implants outside the uterine cavity, typically in the fallopian tube. The absence of an intrauterine pregnancy on transvaginal ultrasound at an hCG level of 2000 IU/L (above the discriminatory zone of 1500-2000 IU/L) strongly suggests ectopic pregnancy. The patient’s left lower quadrant pain and vaginal bleeding are classic signs. Progesterone >4 ng/dL indicates a potentially viable pregnancy, but no intrauterine gestation confirms ectopic risk. Early diagnosis is crucial to prevent tubal rupture and hemorrhagic shock.

Rationale for correct actions:
Intramuscular methotrexate is a folic acid antagonist used to medically manage unruptured ectopic pregnancies by inhibiting trophoblastic cell division. It is preferred when the patient is hemodynamically stable, avoiding surgery. CBC monitors for anemia from bleeding; liver function tests assess methotrexate toxicity risk, as the drug is hepatotoxic. Both are essential for safe medical management.

Rationale for correct parameters:
Hypotension indicates potential internal bleeding from tubal rupture requiring immediate intervention. Referred shoulder pain occurs from diaphragmatic irritation by blood in the peritoneal cavity, signaling intra-abdominal hemorrhage. Monitoring these signs allows early detection of complications.

Rationale for incorrect conditions:
Spontaneous abortion typically shows declining hCG and intrauterine findings of miscarriage, which are absent here. Molar pregnancy presents with markedly elevated hCG (>100,000 IU/L) and characteristic ultrasound “snowstorm” appearance, not seen. Cervical insufficiency causes painless cervical dilation in the second trimester, not early pregnancy pain with bleeding.

Rationale for incorrect actions:
Dilation and curettage is indicated in incomplete abortion, not ectopic pregnancy. Cervical cerclage treats cervical insufficiency, unrelated to this presentation. Oxytocic agents induce uterine contractions in miscarriage or labor, not ectopic management.

Rationale for incorrect parameters:
Size of uterus is irrelevant here because no intrauterine pregnancy is seen. Uterine cramping is nonspecific and more relevant in miscarriage. Leakage of amniotic fluid occurs in membrane rupture, not ectopic pregnancy.

Take-home points:

• Absence of intrauterine pregnancy at hCG >1500 IU/L suggests ectopic pregnancy.
• Methotrexate is first-line medical treatment for stable ectopic pregnancies.
• Hypotension and referred shoulder pain are critical signs of rupture and hemorrhage.
• Differentiation from miscarriage, molar pregnancy, and cervical insufficiency is vital for appropriate care.

The nurse should identify that the client is at the greatest risk for preterm birth due to fetal fibronectin.

Rationale for correct answers:
Fetal fibronectin (fFN) is a glycoprotein found at the maternal-fetal interface, serving as a “biological glue” between the chorion and decidua. Normally, fFN is not detectable in cervicovaginal secretions between 22 and 34 weeks gestation. A level greater than 0.05 mcg/mL, such as this client’s 0.09 mcg/mL, signals disruption of the fetal membranes and an increased risk of preterm birth. It has a high negative predictive value, so a positive result strongly suggests premature labor risk, prompting interventions like tocolytics and corticosteroids to promote fetal lung maturity.

Rationale for incorrect Response 1 options:
Precipitous labor is rapid labor lasting under 3 hours from onset to delivery. Fetal fibronectin does not predict the speed of labor but the risk of preterm onset. This client’s labor is not precipitous based on exam and monitoring.

Chorioamnionitis is an intra-amniotic infection usually accompanied by maternal fever, uterine tenderness, and fetal tachycardia. Fetal fibronectin does not indicate infection.

Preeclampsia involves hypertension and proteinuria after 20 weeks and is unrelated to fetal fibronectin levels.

Rationale for incorrect Response 2 options:
Nitrazine and ferning tests assess membrane rupture. Both are negative here, indicating intact membranes, which does not exclude preterm labor but means premature rupture of membranes (PPROM) is unlikely.

Blood pressure measurements evaluate maternal hemodynamics, not risk of preterm birth.

Take-home points:

• Elevated fetal fibronectin (>0.05 mcg/mL) between 22-34 weeks indicates increased risk for preterm birth.
• Negative nitrazine and ferning tests suggest membranes are intact, helping differentiate preterm labor from PPROM.
• Preterm labor risk should be differentiated from precipitous labor, infection (chorioamnionitis), and hypertensive disorders like preeclampsia.
• Early identification of preterm labor risk allows timely administration of tocolytics and corticosteroids to improve neonatal outcomes.