During routine auditory testing of a 2-day-old baby, the baby failed to respond to high-pitched tones.
Fetal exposure to an antibiotic depends on many factors, such as gestational age, protein binding, lipid solubility, pH, molecular weight, degree of ionization, and concentration gradient. Some antibiotics are even concentrated in the fetal compartment. Tetracycline is contraindicated in all three trimesters. It has been associated with skeletal abnormalities, staining, and hypoplasia of budding fetal teeth, bone hypoplasia, and fatal maternal liver decompensation. Sulfonamides are associated with kernicterus in the newborn. They compete with bilirubin for binding sites on albumin, thereby leaving more bilirubin free for diffusion into tissues. Sulfonamides should be withheld during the last 2 to 6 weeks of pregnancy. With prolonged treatment of tuberculosis (TB) in pregnancy, streptomycin has been associated with fetal hearing loss. Its use is restricted to complicated cases of TB. Nitrofurantoins can cause maternal and fetal hemolytic anemia if glucose 6-phosphate dehydrogenase deficiency is present. Chloramphenicol is noted for causing the gray baby syndrome. Infants are unable to properly metabolize the drug, which reaches toxic levels in about 4 days and can lead to neonatal death within 1 to 2 days.