MCB 135E Discussion October 11-15

Mid-Term I Average 87 (+/- 9) Key available in hallway near 102 Donner

Topics Labor and Delivery Cardio-respiratory Changes After Birth The Normal Newborn

Labor and Delivery Parturition Hormones Delivery Phase

Parturition Birth Process –38 Weeks after fertilization –40 Weeks after last menstrual period Onset of Labor –Process that is not completely understood, but involves a combination of mechanical and hormonal factors

Hormones Fetal Hormones Estrogen Progesterone Oxytocin Prostoglandins Relaxin

Delivery Phases Dilation and Effacement Descent and Expulsion Expulsion of the Placenta

Cardio-Respiratory Changes Heart Development Cardiac Outflow Anomalies Normal Fetal Circulation Fetal Cardiac Function Transitional Physiology

Fetal Cardiac Function In adult: –Hypothalamic control of cardiac output Increase Heart Rate Increase Contractile force of myocardium In fetus –Contractile force is at a maximum –Control cardiac output only through increased heart rate

Transitional Physiology Changes in fetal circulation at birth: –Loss of placenta –Opening of pulmonary arteries –Functionality of the lungs Blood is allowed to flow to lungs due to less pressure (the path of least resistance) –Apoptosis of fetal modifications

The Normal Newborn Respiration Assessment of Transition What to Expect

Respiration First breath –Responsible for opening of lungs –30-100mmHg in newborn vs mmHg normal Close ductus arteriosus –First functional, later anatomical Removal of lung fluid

Transition Apgar Scoring The first hours of life Primary vs Secondary Apnea

What to Expect… The first week of life: –Vitamin K control blood clotting and is essential for synthesizing the liver protein that controls the clotting (thrombin) –Antibiotic Eye Drops –Hepatitis B Vaccine –Feeding Increase intake until 1 fluid ounce per hour of milk is consumed –Jaundice Indicator of postbirth adaptations Caused by an incomplete metabolism of bilirubin –Bilirubin is a waste product of hemoglobin breakdown