🤰🏾- Exam 2 Flashcards
Placenta previa
Abnormal implantation of the placenta in the lower uterus at or very near the cervical os
Indications for limited ultrasound scan
(Done quickly for a specific reason)
- determine placental location
- detect presence or absence of fetal ❤️ rate
- assess volume of amniotic fluid
- guide delivery of 2nd twin in a vag birth
- assist with amniocentesis
Doppler ultrasound blood flow assessment
Performed on pregnancies complicated by hypertension or fetal growth restrictions
To identify abnormalities in the diastolic flow
Low vs high levels of MSAFP are associated with what
Low levels associated with chromosomal abnormalities
Ex: Down syndrome, trisomy 21
High levels are associated with open NTD and body wall defects
Ex: anencephaly, spina bifida, hydronephrosis
Alpha-Fetoprotein screening
Done between 16 and 18 weeks
** maternal weight can misconstrue results **
Screening test , not diagnostic
Done to detect possible open body defects and congenital anomalies
Chorionic villus sampling
The villi are fetal tissues
Done between 10 and 12 weeks to diagnose fetal chromosomal, metabolic or DNA abnormalities
Can cause limb reduction defects (LRD)
Give RhoGAM to 🤰🏾that is Rh-negative
Amniocentesis
Done at 15 to 20weeks
Can cause foot deformations
May resume normal activities 24hrs after procedure
Aspirate 20mL of amniotic fluid for testing
Give RhoGAM
Amniocentesis in 2nd vs 3rd trimester
2nd - done to identify chromosome abnormalities
3rd - done to determine fetal lung maturity and test for fetal hemolytic disease (anemic , jaundice and hydrops fetalis)
Percutaneous umbilical blood sampling
Aka cordocentesis
Aspiration of fetal blood from the umbilical cord for prenatal diagnosis and management rH disease, abnormal blood clotting and determination of the acid-base stays of the fetus
can deliver therapeutic drugs/blood trans that can’t be delivered to the fetus in another way
Umbilical VEIN is used because it’s larger
3 goals and types of antepartum fetal surveillance
Goals
- Determine fetal health or compromise as accurately as possible
- Reduce perinatal morbidity and mortality
- Guide intervention by the obstetric team
Types: nonstress test, contraction stress and biophysical profile
Non-Stress Test
Used to determine reactive/reassuring fetal movement = At least 2 fetal heart accelerations with or without movement occur within a 20min period .
before the NST, the woman should void
Fetal acceleration is classified as
An increase of heart rate at least 15 beats lasting at least 15 secs
Preterm acceleration in a NST
In a fetus younger than 32wks two accelerations that peak 10 beats and lasts for 10 secs - within a 20min window
What is the concern with FHR accelerations without fetal movement
Fetal hypoxemia and acidosis
Uteroplacental insufficiency
Inability of placenta to exchange oxygen, carbon dioxide, nutrients and waste products properly between maternal and fetal circulations
CST interpretation: negative, positive, equivocal or unsatisfactory
Negative- (reassuring) no late deceleration present
Positive- (abnormal) late decelerations are present
Equivocal- test must be redone
Unsatisfactory- fewer than 3 contractions in 10mins occurred; unable to test
What is used to induced contractions in a contraction stress test (CST)
Diluted oxytocin
Oligohydramnios
Decreased amniotic fluid
Which suggests prolonged fetal hypoxia
Biophysical profile (BPP)
Assess FHR, fetal breathing movements, gross fetal movements, fetal muscle tone and amniotic fluid volume
Gradual hypoxia concept
Fetal activity is effected in stages with how long hypoxemia lasts
- loss of FHR reactivity (occurs first)
- reduced, then absent, fetal breathing movements
- reduced, then absent, gross (large) fetal movements
- reduced fetal tone
- prolonged hypoxemia: reduced amniotic fluid volume (occurs last)
Absence of fetal tone indicates what
Advanced asphyxia and acidosis
BPP score interpretation
Less than 4= deliver baby now
6= equivocal
8-10= normal
Maternal assessment of fetal movement
Assess the kick counts within a time period
Fetal circulation umbilical vein vs arteries
Vein- carries oxygenated blood TOWARD the fetus
Arteries- dexoxygenated blood AWAY from the fetus to the placenta
Adequate fetal oxygenation needs what 5 related factors
1 normal maternal blood flow and volume to the placenta
2 normal oxygen saturation in maternal blood
3 adequate exchange of oxygen and carbon dioxide in the placenta
4 an open circulatory path between the placenta and the fetus through vessels in the umbilical cord
5 normal fetal circulatory and oxygen-carrying functions
5 factors of fetal ❤️ rate regulation
1 autonomic nervous system
2 baroreceptors
3 chemoreceptors
4 CNS
5 adrenal glands
FHR and parasympathetic vs sympathetic nervous system
Sympathetic- increases ❤️ rate through release of epinephrine and norepinephrine
Parasympathetic- reduces ❤️ rate and maintains variability through stimulation of the vagus nerve / exerts greater influence as the fetus matures between 28 and 32wks gestation
fhr in the term fetus is lower than in the preterm fetus
Compromise of fetal oxygenation may occur because of what 5 factors
1 maternal cardiopulmonary alterations
2 hypertonic uterine contractions
3 placental disruptions
4 umbilical blood flow interruptions
5 fetal alterations
Doppler transducer
Produces a two-part muffled sound that resembles the sound of a galloping 🐴.
Represent closure of the heart valves during systole (mitral / tricuspid) and diastole (aortic / pulmonic)
Tocotransducer
Detects changes in abdominal contour to measure uterine activity “assess contractions”
Classification of variability
Absent - undetectable
Minimal - undetectable to 5 bpm
Moderate - 6 to 25 bpm
Marked - greater than 25 bpm
Early decelerations
Fetal head compression increases ICP causing the vagus nerve to slow the ❤️ rate - not associated with fetal compromise and require no intervention
Mirror contractions
Late decelerations
Deficient exchange of oxygen and waste products in the placenta (uteroplacental insufficiency)
Intervention: reposition to Left side, give oxygen, increase fluids, decrease pitocin
Variable decelerations
Conditions that reduce flow through the umbilical cord
Interventions: reposition, decrease pitocin, give amnioinfusion
Aminoinfusion
Infusion of a sterile isotonic solution into the uterine cavity during labor to reduce umbilical cord compression
May also be done to dilute meconium in amniotic fluid and reduce the risk that the infant will aspirate thick meconium at birth
Contraction frequency
Beginning of one contraction to beginning of the next
Contraction duration
Beginning to end of each contraction
How long contraction lasts
Cord blood gases and pH
Umbilical cord blood analysis is used to asses the infants oxygenation and acid-base balance immediately after birth
What is the physiologic retraction ring
The division between the upper and lower segments of the uterus
Upper- contracts actively and during labor becomes thicker
Lower- and cervix contracts passively , during labor both become thinner and are pulled upward
Effacement vs dilation
Effacement is thinning and shortening of uterus
Dilation is opening of uterus
During labor which cervix remains thickest a multipara or nullipara
Multipara’a cervix remains thicker that the nullipara’s cervix
Increment, acme, decrement
3 phases of a contraction:
Increment- period of increasing strength
Acme- aka peak period during which the contraction is most intense
Decrement- period of decreasing intensity
Physiological effects of the birth process:
Maternal response
5 systems
Cardiovascular - increase in maternal blood volume, increasing BP decrease ❤️ rate
Respiratory - increased respirations , can lead to respiratory alkalosis
GI - decreased motility can cause nausea and vomiting
Urinary - decreased sensation of a full bladder
Hematopoietic -
Respiratory alkalosis
Result of hyperventilation when she exhales too much carbon dioxide
Presentation:
Tingling of hands and feet, numbness and dizziness
Intervention:
Help mom slow her breathing and breathe into a paper bag to restore normal carbon dioxide levels
Physiological effects of the birth process:
Fetal response
3 systems
Placental circulation-
Cardiovascular- alterations in ❤️ rate
Pulmonary-
What are the 4 components of the birth process
Powers- uterine contractions (1st stage) and pushing efforts (2nd stage)
Passage- maternal pelvis and soft tissues
Passenger- fetus, membranes and placenta
Psyche- psychological response to labor is influenced by anxiety, culture, expectations, life experiences and support
Fetal lie
The orientation of the long axis of the fetus to the long axis of the woman
Longitudinal- in 99% of pregnancies parallel to the long axis of woman. Head or feet enter pelvis first
Transverse- long axis of fetus is at right angle to long axis of mom
Fetal attitude
The relation of fetal body parts to one another
Flexion- (normal) head flexed toward chest and arms and legs flexed over thorax
Extension- (abnormal) head and right arm are extended
Fetal presentation or presenting part
The fetal part that first enters the pelvis:
1 cephalic
2 breech
3 shoulder
cephalic presentation with fetal head flexed most common
4 variations of Cephalic presentation
Vertex- or occiput presentation. Most common. Fetal head is fully flexed
Military- head in neutral position. Neither flexed or extended. Occipitofrontal presenting
Brow- fetal head partly extended. Supraoccipitomental presenting
Face- head is extended. Occiput near fetal spine. Submentobregmatic presenting