TNF blockers Enbrel and Humira were originally developed for the treatment of rheumatoid arthritis. By blocking the action of TNF-alpha, these drugs tip the immune balance from a Th1-dominated, to a more "baby-friendly" Th2 state, which encourages successful implantation and reduces the risk of miscarriage. In patients with cytokine-damaged eggs, anti-TNF-alpha medications are usually taken for several months until healthy eggs are produced.
