Apparently but not surprisingly there seems to be much disagreement among doctors. I have been through careful discussions with my rheumatologist on this topic recently.
There are two main issues with TNF-α inhibitors and pregnancy. I am taking Adalimumab/Humira, a pregnancy class B. I am able to stretch my intervals to six instead of two weeks between injections. Does Humira (big dose or my small dose) interfere with implantation since in theory TNF is important for this process? According to my doctor, there are no studies that support this, and in fact there are many case reports that report normal conception on therapy.
Second, are there increased birth defects in fetuses born to mothers on biologics? In recent studies the rate of both spontaneous abortions and congenital anomalies parallels the normal population. There is a presentation from the OTIS registry (looking at pregnancy outcomes in patients with autoimmune disease) supporting no additional risk.
I agree with Megan. 6 months seems like an overly cautious recommendation. Recommending termination of pregnancy is outright irresponsible. Lots of women have conceived, gone to term and given birth to healthy babies while ON the biologics. While surely not the ideal scenario, it might in some cases (severe cases of AS) constitute the lesser of two evils and on that basis constitute the more sound recommendation. There will in these cases of severe disease be a high risk of uncontrolled systemic inflammation if biologics therapy is discontinued prior to conception or during pregnancy. The two rheumatologists in two countries that I consult with have both given me the green light to make my own informed decision weighing the two evils. Together we have formulated an agreement that sounds like this: I can stay on Humira UNTIL conception happens. I would stay off it during organogenesis and the whole first trimester. If necessary, I would resume and stay on Humira until end of term.
As my doctor says, even though this is still a relatively new drug in terms of pregnancy, there is no good evidence to suggest that harm outweighs benefit. It might be blue-eyed but I do take comfort in this. And no, I am not yet pregnant.
All the best,
N
