What lymphocytes are known to damage pregnancies?

The cytokines are chemicals in the body. We can basically divide them into two groups, a group that are defensive and they defend the body against bacteria, viruses and cancer cells, and they are important. And they defend the body through creating an inflammatory environment. That's why we call them pro-inflammatory cytokines. The other group calm down the immune system and they're particularly important during pregnancy, because they calm down the immune system to allow the body to accept the baby, which is half foreign to the body. There is a particular physiological ratio between these two groups, and actually in pregnancy, the issue changed a little bit in favour of the calming cytokines. If the issue is significantly different from normal, in a way that the inflammatory or pro-inflammatory cytokines are high before even trying to conceive, that will not give the good environment inside the womb to receive the embryos or to keep the pregnancy. So we try to get the ratio within normal physiological levels before we start trying for pregnancy.