The kidney is not one large filter. Each kidney is made up of about a million filtering units called nephrons. Each nephron filters a small amount of blood. The nephron includes a filter, called the glomerulus, and a tubule. The nephrons work through a two-step process.
Generally speaking, first babies tend to engage from about 34 weeks to 36 weeks. However, some babies only engage once labour starts. Try not to worry, though. Even if your baby hasn't engaged by the time labour starts, in most cases, it's not a problem.
Ashley Wibbenmeyer, whose engagement will be almost three years by her wedding date in October 2013, says she is waiting to walk down the aisle because of school. âThe main reason we waited to get married was so that I could finish up my master's program,â she says.