93of psoriasis and psoriatic arthritis (PsA) for several years. As such, there is still little
evidence on the safety of the use of UST in pregnancy; however, what little data that
is available comes from animal studies and case reports in the dermatology
literature.
Pregnancy outcomes in animal studies have been mixed. One study of another
IL-12/IL-23 antibody used in pregnant monkeys resulted in masculinization of the
female infants [ 79 ], while use of UST during pregnancy and nursing in macaques
showed no adverse pregnancy or fetal outcomes [ 80 ]. Importantly, in this last study,
the rates of spontaneous abortions were similar in the UST-exposed and UST-
unexposed cohorts.
In humans, data on the safety of use in pregnancy is limited to unpublished data
from clinical trials and from several case reports of UST use during pregnancy. As
of June 2010, the unpublished data from the clinical trials for the use of UST for
treatment of psoriasis included 42 exposures in pregnancy which resulted in 10 live
births of normal infants, 2 live births with adverse events (no further details pro-
vided), 6 SAs, 8 elective abortions, and 16 unknown outcomes [ 81 ]. There has been
only one case report of an adverse pregnancy outcome which occurred in a 35-year-
old smoker with a 10-year history of psoriasis and two prior healthy pregnancies
who was diagnosed with an unintentional pregnancy following her fifth UST injec-
tion [ 82 ]. Despite smoking cessation, she experienced a SA at GW 12. All other
case reports of UST exposure prior to conception [ 83 ] and during pregnancy [ 84 –
86 ] have resulted in full-term, healthy infants with normal development at up to
16 months of follow-up [ 85 ].
The most current consensus statement regarding the use of UST in pregnancy
acknowledges that the current evidence does not show an increased rate of adverse
fetal outcomes with intrauterine exposure; however, given the limited amount of
evidence available, UST should only be used during pregnancy when other treat-
ment options which are compatible for use during pregnancy are not effective to
control maternal disease [ 87 ]. Discussion regarding the possible risks and benefits
of continuing therapy needs to occur on a case-by-case basis.
Breastfeeding While on Biologics
Anti-TNF Agents
Two early case reports of IFX use during breastfeeding reported undetectable drug
levels in breast milk (samples obtained on three occasions in one study [ 22 ] and
obtained daily for 30 days in the other [ 88 ]). Another study looking at the excretion
of IFX into breast milk in three patients with Crohn’s disease (one obtained 7 days
after IFX infusion, one at 5 days after IFX infusion, and one at 43 days after IFX
infusion) also reported undetectable levels in the breast milk of all three women
[ 89 ]. More recent studies, however, have shown that anti-TNF drug levels are
detectable in breast milk. In a similar study of three patients with Crohn’s disease
6 Biologics in Pregnancy and Breastfeeding