π€°πΎ- Exam 2 Flashcards
Placenta previa
Abnormal implantation of the placenta in the lower uterus at or very near the cervical os
First trimester ultrasound
Done at 5-6 weeks
Transvaginal
Done to confirm pregnancy and measure gestation with CRL (crown-rump length)
Indications for limited ultrasound scan
(Done quickly for a specific reason)
- determine placental location
- detect presence or absence of fetal β€οΈ 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 π€°πΎthat 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 canβt be delivered to the fetus in another way
Umbilical VEIN is used because itβs 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