Download Labor, Delivery, and Changes at Birth

Labor, Delivery, and Changes
at Birth
Fred Hill, MA, RRT
Fetus in Uterus
Fetus in Uterus
Events of Birth (Maternal)
Rupture of membranes
Dilation of cervix
Contraction of uterus
Separation of the placenta
Shrinking of the uterus
Stages of Labor & Delivery
 Stage I: Onset of regular contractions to full
dilation and effacement of the cervix


Primigravida: 16 – 18 hours
Multigravida: 7 – 12 hours
 Stage II: Full dilation (10 cm) and effacement of
the cervix to delivery of the baby


Primigravida: 1 – 2 hours
Multigravida: 20 mins
 Stage III: Delivery of the baby to delivery of the
placenta


Primigravida: 3 – 4 mins
Multigravida: 4 – 5 mins
Tocolysis
Beta-2 sympathomimetics
 Terbutaline
sulfate
 Ritodrine hydrocholoride
Magnesium sulfate
Indomethacin
Calcium channel blockers
Dystocia
Uterine dysfunction
Abnormal fetal presentation
Cephalopelvic dysproportion
 Hydrocephalus
 Excessive
fetal size (maternal diabetes)
 Small pelvic dimensions
Abnormality in shape of birth canal
Abnormal Fetal Presentation
Normal presentation: Vertex ( head
first), 95%
Abnormal presentation
 Cephalic
 Breech
(buttocks down)
 Face
 Brow
 Shoulder
 Transverse
lie
Vertex Presentation
Cephalic Presentation
Face Presentation
Complete Breech
Footling Breech
Frank Breech
Transverse Lie
Other Problems
Prolapse of umbilical cord
Cord wrapping around fetus
Placental abnormalities
 Placenta
previa: Implantation in lower
uterus
 Abruptio placentae
Placenta Previa
Abruptio Placentae
Other Risky Deliveries
Cesarean deliveries
Multiple gestations
Changes at Birth
Vaginal squeeze when head presents
Presentation of chest and recoil of chest
First breath: high initial pressures (-100 cm
H2O)
Succeeding breaths require less negative
pressure
Remaining liquid in lungs
 Expelled
by coughing and sneezing
 Absorption into lung interstitium into lynphatics
Fetal Circulation
Fetal to Adult Circulation
Major changes
 First and subsequent breaths
 Reduces pulmonary vascular resistance
 Air replaces liquid surrounding vasculature
 ↑ PaO2 → pulmonary vasodilation
 Increase in systemic vascular
 Clamping of umbilical cord
resistance
R → L Shunting changes to L → R
 Foramen ovale closes: mechanical
 Ductus arteriosus begins to close due
to
chemical changes
 Cessation of blood flow leads to constriction of:
Ductus venosus
 Umbilical arteries and veins
