Physiology of Pregnancy Flashcards
What is the average length of pregnancy?
40 weeks or 10 months
When is a pregnancy considered full term?
38-40 weeks
When is a pregnancy considered post term?
40-42 weeks
When is a pregnancy considered preterm?
<38 weeks
how do you determine the gestational age?
Either by the date of the last menstrual cycle or via ultrasound
What are some issues with using the date of the last menstrual cycle to determine gestational age?
- Assumes a 28 day cycle
- bleeding could also be caused by early pregnancy or contraceptives
- Incorrect patient recollection
How do you determine the gestational age via ultrasound?
Crown to rump length
What hormone is responsible for a positive result on a pregnancy test?
Human Chorionic gonadotropin
Describe what the levels of estrogen and progesterone do throughout the pregnancy
Levels slowly increase throughout the pregnancy
What is the hormone responsible for lactation?
Prolactin
What physiological changes occur within the pregnant mother?
- Fluid and electrolyte composition
- Acid base balance
- Hematological changes
- Respiratory changes
- Cardiovascular changes
- Gastrointestinal changes
- Renal
- Central and peripheral nervous system
- Endocrine system
- Musculoskeletal
- Dermatological
What are the implications of a left shift on the oxyhemoglobin curve?
- increased oxygen affinity
- Reduced oxygen delivery to the tissues
What is a left shift on the oxyhemoglobin curve caused by?
- High pH
- Low temp
- Low 2,3 BPG
- Fetal Hgb
What is the function of relaxin?
relaxes the joints
What are the implications of a right shift on the oxyhemoglobin curve?
- Reduced oxygen affinity
- Increased oxygen delivery to the tissues
What is a right shift on the oxyhemoglobin curve caused by?
- Low pH
- Increased CO2
- High temp
- High 2,3 BPG
What are common respiratory conditions caused by pregnancy?
- Asthma
- Pulmonary Edema
- Pneumonia
- Covid 19
What is the most common respiratory condition in pregnancy?
Asthma
A PaCO2 in the normal range in a pregnant patient is indicative of what?
Impending respiratory failure
What are the risks to the fetus if the mother is acidotic?
- Fetal Hypoxemia
2, Impairs ability to offload CO2 via the placenta
Why are pregnant individuals at risk for developing a pulmonary edema?
- Increase in blood volume
- Red blood cell mass increases by 20-30%
- Albumin increases by 30%
The increase in blood volume outpaces the increase in protein content resulting in a lower oncotic pressure
T/F: The immune system is not altered during pregnancy
False. Adaptions occur during pregnancy that can leave the mother vulnerable to infections
What factors increase the risks associated with intubation in pregnant individuals?
- Mucosal edema of the upper airway
- Gestational weight gain
- Displacement of the diaphragm
- Decreased esophageal sphincter tone
- Increased oxygen consumption
What medical condition can make intubations even riskier in pregnant patients?
Preeclampsia
How does preeclampsia increase the risk of death during intubations?
Edema in upper back and neck that can extend to the airway and tongue
What are the respiratory goals of support for pregnant patients?
- Maternal PaO2 of 70 mmHg
- Maternal acid bases status
What is the target PaCO2 for maternal patients?
28-32 mmHg
What is an elevated PaCO2 associated with in pregnant patients?
- Decreased Uterine perfusion
- Fetal hypoxemia
What might you expect to see in pregnant patients on a ventilator in regards to PIP and PEEP?
Increased PIP and PEEP
What considerations should you be aware of when mechanically ventilating a pregnant patient?
- increased chest wall compliance (due to relaxin)
- Increased abdominal pressure
T/F: Prone positioning should be avoided in pregnant patients
False, prone positioning can be successful in pregnant patients however it still carries the risks that prone positioning of normal patients carry
What is delayed prenatal care associated with?
- Increased risk of preterm birth
- Low birthweight
- Neonatal death
What factors should be considered when assessing whether or not a pregnancy is high risk?
- Maternal medical history
- Spouse medical history
- Family medical history
- Pregnancy history
What are the terms used to determine pregnancy details?
Gravida
ParityW
What does Gravida mean?
number of confirmed pregnancies, regardless of outcome
What does parity mean?
Number of pregnancies that went beyond 20 weeks viability
Elizabeth is a 32 year old who is pregnant for the 3rd time and has a 3 year old at home. What is GP score?
G3P1
Amy is a 22 year old who just confirmed her first pregnancy
G1P0
Laura and her husband have struggled with infertility, she is currently pregnant for the 5th time and has 2 children at home
G5P2
Describe a normal blood gas in a healthy mother
PaO2 = 110
PaCO2 = 28-32
HCO3 = 20
A blood gas for a healthy mother can be described as
Partially compensated alkalosis
Describe the respiratory rate in pregnant patients and the results of said respiratory rate
- Increased Respiratory rate
- Increased minute ventilation
- higher PaO2
- Lower PaCO2
