Speed ratings on tires are expressed in letters and are generally listed along with the load index for a tire after the size, for instance 245/40R18 93H. 93 is a load index and the H is the speed rating .â¦. What Does Z Mean On The Tires | Zr Speed Rated | Zr Rating. 1  Differences in Tire Speed Ratings Explained.
Effacement: Thinning of the cervix. In the last month of pregnancy the cervix will begin to stretch and thin. This is an indication that the lower portion of the uterus is getting prepared for delivery, as a thinner cervix dilates more easily. Your health care provider can check for effacement in the final two months of pregnancy.
The cervix is rigid and closed before pregnancy, but it softens and elongates during pregnancy. However, during labor, the cervix shortens and dilates to allow the passage of your baby. Cervical shortening before 37 weeks of pregnancy increases your risk of giving birth to a premature baby. A baby is usually born about 38 weeks after conception. Although the cervix gradually softens and effaces (decreases in length) as the baby grows bigger in the uterus, it does not open or dilate until you are ready to give birth. If your cervix is short before the 37th week, you may go into preterm labor.