Excess Vitamin A

A 25-year-old woman goes to the clinic for the evaluation of worsening acne. The lesions are painful, and the patient is concerned as the symptoms have worsened. Her acne has been present for the past 2 years. Past medical history is otherwise unremarkable. She is sexually active with a male partner and uses condoms occasionally. The patient currently uses topical erythromycin and topical tretinoin, and she washes her face twice daily with benzoyl peroxide. Vitals are within normal limits. Physical examination shows multiple large  >5 mm cystic nodules scattered over the face and upper trunk. The remainder of the examination is unremarkable. The physician switches the patient to oral isotretinoin and schedules her for the next follow-up. If the patient conceives while on this new medication, which of the following would her fetus be most at risk of developing?