Which of the following is a critical nursing intervention during the first trimester to prevent congenital anomalies?
Administering corticosteroids
Monitoring fundal height
Educating on teratogen avoidance
Performing Leopold’s maneuvers
The Correct Answer is C
Teratogen exposure during the first trimester poses the highest risk for congenital anomalies due to organogenesis, which occurs between weeks 3 and 8 of gestation. Teratogens disrupt cellular differentiation, DNA synthesis, and tissue morphogenesis, resulting in structural or functional fetal defects. Common teratogens include retinoic acid, ACE inhibitors, valproic acid, alcohol, tobacco, radiation, and certain infections such as rubella and toxoplasmosis. Severity depends on dose, timing, and genetic susceptibility. Avoidance and early counseling are crucial. No safe threshold exists for many teratogens, and even brief exposure can lead to anomalies during this critical developmental period.
Rationale for correct answers
C. Educating on teratogen avoidance is the most critical nursing intervention in the first trimester. This is the peak window for organ development, so exposure to substances like alcohol, tobacco, certain medications, or infections can lead to major congenital anomalies. Timely education minimizes preventable teratogenic risk.
Rationale for incorrect answers
A. Administering corticosteroids is used in the second or third trimester, typically between 24 and 34 weeks, to promote fetal lung maturity in cases of preterm labor risk. It does not prevent congenital anomalies and is not a first trimester intervention.
B. Monitoring fundal height is not applicable in the first trimester because the uterus remains a pelvic organ until around 12 weeks. Fundal height measurements begin after 20 weeks gestation as a tool for tracking fetal growth, not anomaly prevention.
D. Performing Leopold’s maneuvers is relevant in the third trimester, typically after 28 weeks, to assess fetal position and presentation. It is unrelated to early congenital anomaly prevention and not useful in the first trimester.
Take home points
• Teratogen exposure in the first trimester can cause irreversible structural defects.
• Weeks 3–8 are the most critical for organogenesis and highest teratogenic risk.
• Nursing education on substance avoidance is essential during early prenatal visits.
• Not all common interventions are appropriate or effective in the first trimester.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
Fetal sexual differentiation begins early but genitalia visualization on imaging is influenced by several developmental milestones. Testosterone, secreted by fetal Leydig cells, influences external genitalia starting from week 8. However, distinct labioscrotal and phallus development features become ultrasonographically visible around week 14. The normal fetal heart rate is 110–160 bpm, and accurate sex determination depends on genital tubercle angle, with full differentiation by week 14. Chromosomal sex is determined at conception (XX or XY), but phenotypic differentiation requires hormonal influence, especially dihydrotestosterone.
Rationale for correct answers
D. By week 14, the external genitalia are typically developed enough to be distinguished by ultrasound. The scrotal sac and penile shaft in males, and labial folds in females, become distinct. Visualization accuracy improves with high-resolution transabdominal ultrasound and adequate amniotic fluid volume.
Rationale for incorrect answers
A. Week 8 marks the start of genital ridge differentiation into either testes or ovaries under influence of the SRY gene in XY embryos. However, external genitalia are still undifferentiated and identical in appearance in both sexes, making ultrasound distinction impossible.
B. By week 10, internal reproductive structures such as Müllerian and Wolffian ducts begin differentiating. However, external features remain ambiguous on imaging. At this stage, the genital tubercle is still forming and appears similar in both sexes.
C. Week 12 is the transitional phase where the external genitalia begin to show early signs of sexual differentiation. However, the features are often subtle, and accurate identification on ultrasound remains unreliable due to overlapping characteristics and suboptimal visualization.
Take home points
• Ultrasound visualization of external genitalia becomes reliable around week 14 of gestation.
• Phenotypic differentiation requires androgens such as testosterone and dihydrotestosterone.
• Chromosomal sex is determined at fertilization, but visible genitalia emerge later.
• Genital tubercle angle and shape are early markers but lack specificity before week 14.
Correct Answer is B
Explanation
Human chorionic gonadotropin (hCG) is a glycoprotein hormone produced by syncytiotrophoblasts of the developing placenta beginning around day 6–8 post-fertilization. Its primary role in early pregnancy is to maintain the corpus luteum, which in turn secretes progesterone to sustain the endometrial lining and prevent menstruation. hCG levels double every 48–72 hours in a viable early pregnancy, peaking around 100,000 mIU/mL by weeks 8–11, then gradually decline. Normal range at 4 weeks gestation is approximately 5–426 mIU/mL. hCG also promotes immune tolerance, supports placental growth, and is the basis for urine and serum pregnancy tests.
Rationale for correct answers
B. hCG maintains the corpus luteum during the first 8–10 weeks of pregnancy, ensuring continued secretion of progesterone, which is essential for maintaining the decidua and preventing uterine contraction. Without hCG support, the corpus luteum would regress and lead to pregnancy loss.
Rationale for incorrect answers
A. Fetal lung maturation is not influenced by hCG. This function is regulated by cortisol and surfactant production, which are stimulated by glucocorticoids such as betamethasone during the third trimester.
C. Fetal weight gain occurs primarily in the third trimester and is regulated by placental nutrient transfer, insulin-like growth factors, and maternal nutrition, not by hCG.
D. Labor contractions are initiated by increased oxytocin, prostaglandins, and estrogen at term. hCG has no role in triggering parturition.
Take home points
• hCG maintains corpus luteum function in early pregnancy to support progesterone production.
• Peak hCG levels occur between weeks 8–11 and decline thereafter.
• hCG is the hormone detected in pregnancy tests.
• It is produced by syncytiotrophoblast cells of the trophoblast.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.