Medically reviewed by Kelly Wood, MD Normal thyroid-stimulating hormone (TSH) levels generally fall between 0.4 and 4.5 ...

Human chorionic gonadotrophin (hCG) is released within hours of fertilization and has a profound ability to downregulate maternal cellular immunity against trophoblastic paternal antigens.

TSH, which declines in the first trimester of pregnancy and returns to normal in the second, does not cross the placenta. Normal is 0.5-5.0mcU/mL. hCG - Human chorionic gonadotropin (hCG ...