Decisions about Category X drugs are not controversial. For instance, methotrexate is an abortafacient and should be avoided for at least three cycles before attempting pregnancy. Dr. Laskin imparted some sobering advice about patients who become pregnant while still on the drug: “This becomes a difficult scenario about how best to advise these women. If it’s less than three months since they have stopped the drug, you have to put on the table the question of termination of the pregnancy.” Leflunomide falls under the same recommendations, he says, and mothers should not nurse while on either drug. Because there are minimal data on MMF, and the critical time for fetal exposure is between four and nine weeks gestation, Dr. Laskin recommends also discontinuing this drug at least six weeks before conception.
Due to risks of cleft palate and digit and eye abnormalities, cyclophosphamide (Category D) should be stopped two to three months prior to conception. Azathioprine is also a Category D drug, but Dr. Laskin’s personal belief is that the drug has a “great safety track record” during pregnancy. Breastfeeding while on the drug, however, is not recommended by the American Academy of Pediatrics (AAP).
The tumor necrosis factor (TNF)–alpha blockers (Category B) currently present a real conundrum for physicians, admitted Dr. Laskin. Until a recent case report of an association between TNF-alpha blockers and VATER syndrome abnormalities in an infant, physicians were still prescribing these medications with some confidence.2 His current advice: withdraw the drug two to three months before conception. In mothers with rheumatoid arthritis who are at high risk for postpartum flare, it’s advisable to reinstitute the drug following delivery. In these women, Dr. Laskin feels that breastfeeding is allowable, even though the AAP has not given TNF-alpha blockers its blessing. His rationale is that the drug’s protein molecules are likely to be digested in the neonate’s stomach.
Dr. Laskin believes that the cleft risk associated with corticosteroids (most are Category C) may be most serious in women exposed during the first trimester—and that the validated risk (3.4%) may not be that much higher than in the general population. “However,” he said, “although this is not a life-threatening defect, put yourself in the position [of the mother], where your baby is going to have one, two, or more surgical procedures to correct the clefting. This is a tough road, and it’s important that everyone be counseled appropriately.” In a study by Dr. Laskin and his colleagues, prednisone (the only Category B corticosteroid) was associated with premature birth, although all the infants were healthy.3 His conclusion: “A healthy mother is a healthy baby. If this woman needs the drug, then you need to keep them on it.”
