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.
well if you have your baby at 37 weeks due to self induction than be prepared for the baby to be a little bit weaker than a baby born at what is classified at term 38-42 weeks,also many babies are not ready or even engaged yet at 37 weeks so you may be forcing something that is not meant to be.