If you're Rh negative and your baby is Rh positive, however, your body might produce proteins called Rh antibodies after exposure to the baby's red blood cells. The antibodies produced aren't a problem during the first pregnancy.he Rh factor test is done during pregnancy to identify a woman's Rh factor. In some cases, the baby's father might need an Rh factor test, too. During pregnancy, problems can occur if you're Rh negative and the baby you're carrying is Rh positive.
Torque converter, opened, interior similar to a retarder. A retarder is a device used to augment or replace some of the functions of primary friction-based braking systems, usually on heavy vehicles. Retarders serve to slow vehicles, or maintain a steady speed while traveling down a hill, and help prevent the vehicle from running away by accelerating down the hill.
Word Origin and History for retard Expand. v. late 15c., make slow or slower, from French retarder restrain, hold (someone) back, keep (someone from doing something); come to a stop (13c.) or directly from Latin retardare make slow, delay, keep back, hinder (see retardation). Related: Retarded; retarding. The noun is recorded from 1788 in the sense retardation, delay; from 1970 in offensive meaning retarded person, originally American English, with accent on first syllable. Other words used for one who is mentally retarded include retardate (1956), retardee (1971).