**one of the FIRST indications of fetal compromise is a NR-NST Contraction Stress Test (CST) or Oxytocin Challenge Test (OTC) o Purpose: evaluate O2 and CO2 exchange o Indications: placental insufficiency or fetal compromise o Procedure: 2 monitors and NO late decels! Stimulate nipples by hand/with pump to cause oxytocin release. If no good contractions, give oxytocin. Contractions can be spontaneous or induced Results – want a NEG result (no late decels with 3, 40-60 second contractions) Positive result – consistent late decels with over half of the contractions Risks – hyperstimulation (should be done in environment with tocolytic drugs available) Ultrasound Evaluations o Reasons in the 3 rd trimester Amniotic fluid index (AFI) = oligohydramnios Doppler Flow studies = placental function/IUGR Placental Maturity = grades O-III (more mature = higher grade) Fetal weight estimation = IUGR/Macrosomia (causes calcifications too early) Other Diagnostic Tests AFP (alpha-fetal protein) through quad screen (15-16wk) o If increased = risk for neural tube defects (Above 3.5) (spina bifida, anencephaly, abdominal wall defects, congenital kidney probs, fetal death, and multiple gestation) o If decreased = Down’s o (Normal – 0.5-2.5) o Produced by yolk sac first 6 weeks, then by fetal liver. Levels peak around 15 weeks, then decrease as excreted in fetal urine. Is found in amniotic fluid and mom’s blood Amniocentesis (can be done any trimester, but highest risk in 1 st and 3 rd ) o Perform 15-20 weeks (30-39 weeks for fetal lung maturity) o Use U/S to guide o Can Dx genetic disorders Fluid should be clear o Side effects Possible infection Fetal loss Fetal injury Cramping/contractions = very common Spotting o Indications Mom over 35 Previous child/fam hx of birth defects 11
Abnormal screen/genetic test results Tests for evaluation of Fetal Lung Maturity (Time consuming) o L/S ratio (lecithin/sphingomylin), want a 2:1 ratio Components of surfactant. Ratio evens out at 30-32 weeks Increases at 35 weeks 2:1 ratio (L:S) = indicates fetal lung maturity) o Phophatidyglycerol Levels (PG), released into amniotic fluid at 36w *see if surfactant has been released for the above two tests Don’t measure – it being there is good enough o Shake Test and Foam Stability Test (ethanol, saline, amniotic fluid) Shake x15 sec then wait 15 min (want to see that phosphoglycol is there) Chorionic Villus Testing (CVS) – tests for genetic problems o Detects genetic disorders in the First trimester at 10-12w o Inc risk of preg loss, fetal limb abnormalities o Use US to determine fetal and placental locations o Can be done transcervically/transabdominally o Inc risk ROM, infection, abortion, and Rh sensitization o Benefit: earlier diagnosis of probs than amniocentesis (done at 16-18wk) Fetal Fibronectin (FN): glycoprotein produced by trophoblast and other fetal tissues o Positive findings = PTL and preterm ROM within 2 weeks o IS present First half of pregnancy
You've reached the end of your free preview.
Want to read all 39 pages?