APA	antiphospholipid antibodies
APS	antiphospholipid antibody syndrome
cGMP	cyclic guanosine monophosphate
CTLA–4	cytotoxic T cell antigen 4
GMP	guanosine monophosphate
IL	interleukin
IR	insulin resistance
MTHFR	methylenetetrahydrofolate reductase
NKT	Natural Killer T cell
NO	nitric oxide
NOS	nitric oxide synthase
PBS	phosphate-buffered saline
PCOS	polycystic ovary syndrome
PDE-Is	phosphodiesterase inhibitors
PDE	phosphodiesterase
RPL	recurrent pregnancy loss
SC	sildenafil citrate
TGF-β	transforming growth factor β
TNF-α	tumor necrosis factor α
Treg	T regulatory cell