Pharmacology · patient case question
Which of the following would NOT increase the risk of an orofacial cleft in her baby?
Patient case: Third Trimester, Woken by Toothache
Patient: 29-year-old female, 33 weeks pregnant
Chief Complaint: “The tooth woke me up at two in the morning. It throbs.”
Background: First pregnancy, uncomplicated. Prenatal care up to date, taking a prenatal vitamin with folic acid and iron.
Medications: Prenatal multivitamin
Vital Signs: BP 116/70 mmHg · HR 88 bpm · RR 18 · T 98.4°F
Findings: Tooth #19 has a large MOD amalgam. Lingering pain to cold, spontaneous night pain, TENDER TO PALPATION in the buccal vestibule. No apical radiolucency, no swelling, no mobility.
Show answer and explanation
Correct answer: D. Iron deficiency
- A. Tobacco IS a recognised risk. Maternal smoking raises the risk of orofacial clefting roughly 1.3 to 1.5 fold in a dose-dependent way, and also causes low birth weight and preterm birth.
- B. Alcohol IS a recognised risk. Fetal alcohol spectrum disorder includes midface hypoplasia, a smooth philtrum, a thin upper lip, short palpebral fissures and an increased incidence of clefting. There is no established safe threshold.
- C. Folic acid deficiency IS a recognised risk. Periconceptional folate supplementation reduces both neural tube defects and orofacial clefts, which is why 400 µg daily is recommended before conception and through the first trimester.
- D. CORRECT — this is the EXCEPTION. IRON DEFICIENCY causes maternal anaemia, fatigue, low birth weight and preterm delivery, but it is NOT a recognised cause of cleft lip or palate. Iron is essential for oxygen transport, not for the fusion of the facial processes.
Note: Fusion of the lip is complete by about week 6 and of the palate by about week 12 — so cleft risk is determined in the FIRST trimester, often before pregnancy is recognised. That is the entire rationale for preconception folate.