BOSTON — Data suggesting that pregnant women with psoriasis have poorer outcomes than those without it highlight the need for more research to determine whether the outcome discrepancies are a function of the disease itself, comorbidities, or treatment side effects, according to Dr. Alexa Boer Kimball.
“We know that pregnancy can have an impact on psoriasis—studies have shown that about 50% of women report improvements; 15%-25% worsen; and the rest don't change—but we know less about the effect of psoriasis on pregnancy,” said Dr. Kimball of the department of dermatology at Harvard Medical School in Boston.
In a case-control study of 145 live births in women with psoriasis between 1998 and 2004, investigators at Ben Gurion University of the Negev in Beer-Sheva, Israel, demonstrated an association between pregnancy complications and psoriasis. Specifically, recurrent abortions and chronic hypertension were significantly associated with psoriasis in a multivariate analysis, and psoriasis was an independent risk factor for cesarean delivery (J. Reprod. Med. 2008;53:183–7).
“The findings are not really surprising when you think about the [inflammatory bowel disease] literature and the lupus literature, for example. It's clear that systemic autoimmune diseases can have adverse effects on pregnancies,” Dr. Kimball said at the American Academy of Dermatology's Academy 2009 meeting.
“Unfortunately, our knowledge about pregnancy outcomes in psoriasis is very limited, which in turn limits the treatment guidance that we can offer.” This is due, she said, to the dearth of literature on the topic, the exclusion of pregnant women from most clinical trials, and the low enrollment in pregnancy registries.
Further, said Dr. Kimball, the various regulatory agencies are not consistent in interpreting numerical data regarding drug safety in pregnancy.
In one study comparing the pregnancy risk classification of 236 commonly used drugs by three international regulatory agencies—the U.S. Food and Drug Administration, the Australian Drug Evaluation Committee, and the Swedish Catalogue of Approved Drugs—only 26% of the drugs were placed into the same risk category, she said (Drug Saf. 2000;23:245–53).
“Theoretically, these groups should be looking at the same data and arriving at essentially the same conclusions. The fact that they're not tells you that there is a substantial subjective review component to how we evaluate this information,” she said.
For these reasons, providing therapeutic guidance to pregnant women with psoriasis is “incredibly challenging,” Dr. Kimball said. The challenge is exacerbated by several social and environmental considerations, including the fact that “women today are under extraordinary pressure not to expose their babies to unknown and unnecessary risks, which may make them more likely to forego therapy that they might actually need,” she said. “In counseling these patients, there really obviously has to be a very open communication about that, although you really can't make the choice for them. It's a very personal decision about the risks they're willing to take.”
Similarly, there is tremendous pressure on women to breastfeed for long periods of time, which can also have an impact on treatment decisions. “A woman may decide to hold off on treatment while she's breastfeeding, and again that's a personal decision, but recognize that it may be a really substantial sacrifice, and in cases of psoriatic arthritis in particular, it may not be all that good for them over time,” she said.
In addition to helping patients determine how to proceed with treatment once they are pregnant, patient counseling should address exposures that might have already happened. “The critical period in all pregnancies for fetal malformations is early, in the first trimester, and lots of women are exposed to drugs before they even know they're pregnant,” said Dr. Kimball.
“In situations involving major risks, referral to a genetics counselor can be useful, but it's also important to remind patients that, under the best of circumstances, not all pregnancies turn out perfectly. The developmental disorder rate [in the general population] is about 3% at birth and about 8% by age 5. It's important to give that information to women so they don't feel overly guilty about the choices they're making,” she said.
“So what can we actually recommend?” Dr. Kimball asked. “For first-line therapy, moisturizers can be used with reckless abandon, and low-potency topical steroids have been determined to not be a risk.” Systemic steroids, on the other hand, should be avoided in the first trimester because of the association with cleft palate, she said.
The second-line treatment algorithm includes narrow band ultraviolet B (UVB) phototherapy, if feasible, “but this may be a challenge if, for example, the pregnant woman has other kids at home or just doesn't have the flexibility in terms of scheduling,” Dr. Kimball said. “Home UVB is an option, and tanning beds—although problematic for other reasons—in a severe patient might be worth considering if they really have no other options.”