Effects of Pregnancy on the Mother and Labor Anatomy & Physiology Mrs. Quezada

Aim: What changes occur in a mother during pregnancy? Anatomical changes Female reproductive organs become engorged with blood Uterine enlargement exerts pressure on abdominal and pelvic organs

Lordosis- accentuated lumbar curvature Relaxin- hormone produced by the placenta that causes the pelvic ligaments to relax and pubic bones to widen and become more flexible

Gastrointestinal changes Elevated progesterone causes nausea Crowding of the digestive system can cause heartburn Decline in mobility of the digestive system causes constipation

Urinary System changes Kidneys produce more urine during pregnancy due to increased metabolic rate and waste from the fetus Uterus compresses the bladder

Respiratory System changes Nasal mucosa become congested in response to estrogens Tidal volume increases, to take in more oxygen for the fetus Dyspnea- difficulty breathing, can occur later in pregnancy

Cardiovascular changes Blood volume increases 25-40% to accommodate the needs of the growing fetus Blood pressure increases to propel extra blood around the body

Aim: What changes occur during parturition? Parturition- childbirth, usually occurs within 15 days of the due date of the baby Labor- series of events that expel the infant from the uterus

Initiation of Labor Labor is brought about by interaction of several hormones The fetus produces adrenocortical hormones, which stimulate a rise in estrogen from the placenta

Increased production of surfactant protein A by the fetal lungs softens the cervix Estrogen causes the formation of oxytocin receptors on the myometrium and antagonizes the calming effect of progesterone on the uterus

Braxton Hicks contractions- weak, irregular contractions of the uterus may occur- false labor As labor gets closer, oxytocin (fetal cells) and prostaglandins (placenta) are produced, which are uterine muscle stimulants

Stages of labor The dilation stage- time from labor’s onset until the cervix is fully dilated (10 cm) Longest phase of labor, 6-12 hours Infant’s head is forced against the cervix by uterine contractions

The expulsion stage- lasts from full dilation until the delivery of the infant Strong contractions occur every 2-3 minutes Mother has an increasing urge to push with the abdominal muscles Crowning occurs when the baby’s head exits

The Placental Stage- delivery of the placenta and its attached fetal membranes (afterbirth) Usually accomplished within 30 minutes after birth of the infant

Adjustments to extrauterine life The newly born infant must adjust to life outside the womb Apgar score- assessment done within 1-5 minutes after birth based on 5 criteria- respiration, heart rate, color, muscle tone, and reflexes