A woman is treated with lithium during pregnancy, the foetus should be tested for?

Appeared in: SCTIMST Staff Nurse - 2016

Explanation

Lithium exposure during the first trimester of pregnancy is linked to an increased risk of congenital heart defects in the fetus.
The most classic cardiac malformation associated with in-utero lithium exposure is Ebstein's anomaly, a defect of the tricuspid valve where it is displaced into the right ventricle.
Due to this risk, fetal echocardiography is the recommended screening test, typically performed around 18-22 weeks of gestation for exposed pregnancies.

Why Other Options Were Wrong

Option A: This is incorrect. Neural tube defects are not the primary concern with lithium use.
Option B: This is incorrect. While some drugs cause urogenital issues, this is not the characteristic defect associated with lithium.
Option D: This is incorrect. Scalp defects are not a known teratogenic effect of lithium.

Related Visual

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Teratogenic effects of lithium during pregnancy as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in counseling women of childbearing age on mood stabilizers about the risks and benefits, emphasizing the need for planned pregnancies to minimize fetal exposure during critical developmental periods.
For pregnant patients on lithium, nurses must coordinate care, including scheduling a high-resolution fetal echocardiogram and monitoring maternal lithium levels, which can fluctuate due to pregnancy-related physiological changes in renal clearance.
After delivery, the nurse should be vigilant for signs of neonatal lithium toxicity (e.g., hypotonia, cyanosis, poor suck reflex) as lithium crosses the placenta and can affect the newborn.

How to Approach the Question

This is a factual recall question testing knowledge of pharmacology and teratology.
First, identify the key drug in the question stem: 'lithium'.
Next, recall the specific teratogenic effects associated with lithium use during pregnancy.
Evaluate each option to see which one matches the known risk profile of lithium. Lithium is classically linked to cardiac issues.
Select the option for 'Cardiac malformations' as it is the most well-documented teratogenic effect.
Mentally eliminate the other options by associating them with different teratogens (e.g., valproate for neural tube defects, ACE inhibitors for urogenital issues, methimazole for scalp defects) to confirm your answer.

Concept Tested & Keywords

Concept Tested: Teratogenic effects of lithium during pregnancy.
Stem keywords: lithium, pregnancy, foetus
Lead-in keywords: tested for
Negative lead-in flag: false

Question ID

Qshp4Tyb8OtEFwlByLLsXM

Reference Book

E6 Robert Boland, Marcia L. Verduin - Kaplan and Sadock's Comprehensive Text of Psychiatry-Wolters Kluwer Health (2024) (pp 1-16525 of 16525) pp. 10764-10766, 8455-8457

E6 Pharmacology Katzung 16e p. 823-825

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