Obstetric Procedures Flashcards
used in first trimester, producing high-resolution images
that are not influenced by maternal BMI
Transvaginal sonogram
Dating accuracy of first trimester sonogram
is ________
+/- 5–7 days.
used any time during the pregnancy, but image quality may be limited by maternal obesity
Transabdominal sonogram
Dating accuracy of early second trimester sonogram is +/- _______
7-10 days.
_____used to assess umbilical artery (UA) and middle cerebral artery (MCA) blood flow.
This modality assesses fetal well-being in IUGR pregnancies as well as fetal anemia in alloimmunized pregnancies.
Doppler ultrasound studies
Indications for obstetrical ultrasound include:
- Pregnancy location & viability, gestational age dating
- Multiple gestation (zygosity, chorionicity, amnionicity)
- Amniotic fluid volume (oligohydramnios, polyhydramnios)
- Fetal growth (IUGR, macrosomia)
- Fetal anomalies, fetal well-being
- Pregnancy bleeding, fetal anemia
ideally performed at 18-20 weeks, looks for anatomic markers of fetal aneuploidy
Genetic sonogram
Specific markers for aneuploidy
nuchal skin fold thickness (strongest predictor), short long bones, pyelectasis, echogenic intracardiac focus, hyperechoic bowel
________ measurement is a screening test, performed between 10-14 weeks, measuring the fetal fluid collection behind the neck.
Nuchal translucency (NT)
A thickened NT increases the likelihood of_____ and ______
aneuploidy and cardiac disease
It is combined with two maternal blood tests _______ and _______) in first-trimester screening to increase the sensitivity and specificity for aneuploidy screening.
(free b-hCG & PAPP-A
_______ is a diagnostic outpatient office procedure performed under ultrasound guidance without
anesthesia. Procedure-related pregnancy loss rate is 0.7%
CVS
In CVS,
Chorionic villi, which are placental precursors, are aspirated from a pregnant uterus between ______ and _____
10 and 12 weeks’ gestation
_______is a diagnostic, outpatient office procedure performed after 15 weeks under
ultrasound guidance without anesthesia. Pregnancy loss rate is 0.5%
Amniocentesis
Fetal karyotyping is performed on _______
amniocytes.
NTD (neural tube defect) screening is performed on amniotic fluid with biochemical analysis ______ and ______
(AFP and acetylcholinesterase).
This transabdominal procedure, performed under ultrasound guidance, aspirates fetal blood
from the umbilical vein after 20 weeks’ gestation
PERCUTANEOUS UMBILICAL BLOOD SAMPLE (PUBS)
Purpose of PERCUTANEOUS UMBILICAL BLOOD SAMPLE (PUBS)
The procedure can be diagnostic (e.g., blood gases, karyotype, IgG and IgM antibodies)
as well as therapeutic (e.g., intrauterine transfusion with fetal anemia).
Procedure-related pregnancy loss rate of PUBS is ________
1–2%.
A _______ is a transabdominal procedure performed with a fiberoptic scope in the operating
room after 20 weeks under regional or general anesthesia
fetoscopy
Indications for fetoscopy include _____ and ____
intrauterine surgery or fetal skin biopsy
Laser is used for coagulating placental vessels in__________.
Skin biopsy may be performed for suspected ______
twin−twin transfusion syndrome (TTTS)
fetal ichthyosis
The pregnancy loss rate of fetoscopy is _______
2−5%.
