Macrocytic Larger than normal cells. Microcytic Smaller than normal cells. Micturition Act of passing urine. Nuchal translucency scanning Ultrasound screening test to measure the maximum thickness of the translucency between the skin and the soft tissue overlying the cervical (neck) region of the spine of the fetus. Nulliparous (woman) Having not yet given birth to any viable infants. Oedema Excessive accumulation of fluid in the body tissues. It can be local because of injury or inflammation, or more general, as in heart or kidney failure which can include pre-eclampsia in pregnancy. Os Cervical opening (internal: to the uterus/ external: to the vagina). PAPP-A Pregnancy-associated plasma protein A: a marker for Down syndrome.