Baby isn't just sleeping her way through this last week. Instead, she is generating hormones and sending signals that life is about to change. One of these hormones will travel to the placenta to initiate labor. During labor, the baby will still be hard at work producing stress hormones that will help her through the process and the shock of the real world. These stress hormones will also encourage her instinct to take her first real breath outside the womb, so it is vital she prep for the big day.
During labor, the baby will experience intermittent blood flow through the placenta thanks to contractions restricting the flow. This process is normal, and as long as the breaks are not very long or come very often, the baby will be able to weather the process relatively unaffected by the lack of consistent flow. The hormones baby has produced in preparation for this event will help her make it through the process of labor and will assist her in maintaining her blood pressure and blood sugar levels after birth.
Upon delivery, the baby is dried to help maintain body temperature and will receive an Apgar Score based upon objective measurements of heart rate, respiratory effort, muscle tone, color, and grimace response. Each of these receives a score of 0 to 2, and the total is the baby's Apgar Score. This test gives caregivers a good assessment of the baby's current health status at the time of birth and, in general, is not an indicator of the baby's future development or intellect. What it DOES do, however, is help guide caregivers to whether or not the baby needs further intervention to help "get their engines going."
If the baby had a long descent through the birth canal, their head will likely have a cone shape to it right away. This shape is a result of molding and is completely normal; this should self-resolve over the next several days.
- American Pregnancy Association - Week 40
- American College of Obstetricians and Gynecologist - How Your Fetus Grows During Pregnancy