Pregnancy Screening and Management Flashcards
1
Q
Initial Basic Lab Studies
A
- Type and Rh, antibody screen
- CBC (Hgb electrophoresis for genetic Dz), rubella titer, varicella
- RPR, HB2Ag, urine C/S & Screen, HIV
- GC/Chlamydia, wet prep, Pap
- Thyroid (Hypo affects neuro dev., hyper can also affect fetus)
2
Q
Lead Levels
A
- Any elevation is dangerous to embryo/fetus (>5)
- Any of the following criteria, check level:
- recent immigration from high Pb contamination
- Living near source of Pb
- Pica
- Occupational exposure
- Environmental contamination
- Cosmetics w/lead, lead-glazed pottery
- Herbal alternative meds
3
Q
Prenatal Screening/Diagnosis
A
- Looking for birth abnormalities (Down syndrome, Spina bifida, etc.)
- Opportunity to prepare, plan for, or elect for terminate
- Options for fetal therapy
4
Q
Prenatal SCREENING
A
- Screening: determines risk for specific abnormality
- Minimal risk (usually blood or serum & US)
- Recommended for ALL women
5
Q
Prenatal DIAGOSTICS
A
- Diagnostic testing: Determines if fetus has abnormality
- Invasive, small risk of loss of pregnancy
- Amniocentesis, CVS
- Recommended for SOME women
6
Q
When/whom to screen
A
- Carrier screening should be offered to all couple when at least 1 member is Caucasian for trisomy
- Ethnic/racial Hx
- Woman age >35yo or Hx of DM
- Father >50yo
- Previous pregnancy or First-relative or close blood relative w/ Hx of abnormality
- Hx of 2+ miscarriages
- Teratogen exposure
7
Q
Types of Prenatal Screening
A
- History
- Carrier Testing
- Multiple marker screening
- Ultrasound
8
Q
Ethnic/Racial Risks for Abnormalities
A
- Tay Sachs: Ashkenazi Jewish, French Canadien
- SCD: African, Mediterranean, Middle East, Carribean
- Thalassemias: Mediterranean, Asian
- Cystic Fibrosis: Northern European Caucasian, Ashkenazi Jewish
9
Q
Neural Tube Defects (NTD)
A
- Spina Bifida
- Anencephaly
- Cephalocele
10
Q
NTD Risk Factors
A
- Folate deficiency
- Folate interfering meds (valproid acid)
- Insulin dependent DM
- UK decent
- U.S. born hispanic women
11
Q
NTD Initial Screening
A
- Maternal AFP Level
12
Q
AFP
A
- Pattern:
- Fetal AFP rises until 13wk
- Maternal AFP rises after 12wk
- Exposed fetal tissue let AFP leak into amniotic fluid
- Maternal AFP is then abnormally high
13
Q
Factors that influence AFP
A
- Maternal weight
- gestational age
- Race/Ethinicity (AA have 10% higher AFP)
- DM
- Multiple gestation
14
Q
When to draw AFP
A
- Draw at 15-20wk
- Adjust for: maternal age, wt, ethnicity, gestational age, & IDDM
- If elevated: US to r/o twins, gestational age, etc.
15
Q
** Causes of Elevated AFP **
A
- Underestimated gestational age
- Multiple gestation
- Fetal death
- NTD, Gastroschisis, omphacele
- Low maternal wt.
- Pilonidal or other fetal cyst
16
Q
** Causes of low AFP **
A
- Overestimated GA
- Gestational trophoblastic Dz (Choriocarcinoma)
- Fetal death
- Trisomies
- Obesity
- DM
17
Q
What to do if AFP is abnormal
A
- Genetic counseling
- Specialized sonography
- Amniocentesis
- Unexplained maternal AFP
- MOST women with abnormal AFP have NL babies
18
Q
Signs of Abnormalities
A
- Banana spine: spina bifida
- Sandal toe: Down syndrome
19
Q
Trisomy Facts
A
- Risk increases at age 35 (higher risk %, more babies born w/DS <35yo)
- AFP low in trisomy 21 (DS) pregnancy
- All women seen before 20wk should be offered screening
20
Q
Trisomy Incidence
A
- DS is most common chromosomal abnormality
21
Q
Ways to Screen
A
- Most screening test have false positive rate of 5%
- Addition of other serum marker tests in 2nd trimester increases accuracy up to 80% (for quad)
- Serum markers + nuchal translucency (NT) can give good results at 11-14wk
22
Q
Triple Screen Findings for DS
A
- Low MSAFP + high HCG + low estriol
- detection ~55-75%
- > 35yo -> detection ~85%
23
Q
Quad Screen Findings for DS
A
- Triple screen + high inhibin-A
- Done b/n 15-22wk (best 16-18wk)
24
Q
1st Trimester Screening (FTS)
A
- NT + B-HCG + PAPP-A (pregnancy associated plam protein A)
- Performed at 10.3-13.6wk
- B-Hcg higher and PAPP-A lower in DS
- Offered only if: sonogram tech who is qualified, lab can do testing, resources to provide counselling, access to CVS if test is positive
- Advantages: high detection rates, reassuring, gives time for decision making, decreased rates of induction for post-term pregnancy
25
Q
Combined FTS and STS = Integrated screen
A
- Screening performed at different times with pt given single result only after all tests are done
- 10-13wk: NT + PAPP-A
- 15-18wk: MSAFP + Estriol + inhibin A
- Advantage: Sn 94%
- Disadvantage: Lack early Dx, physical/emotional results, increased costs
26
Q
US markers for trisomy
A
- 1st Tri: Increased nuchal translucency (most reliable marker)
- 2nd Tri: Nuchal fold
- Other soft markers: absent nasal bone, echogenic bowel, shortened long bones
27
Q
Options for high risk women
A
- FTS at 10-13wk: CVS earliest at 11wk, amnio 14wk, may choose termination 13-15wk
- STS at 15-18wk: amnio, termination
28
Q
Sequential Screening
A
- Integrated screening w/results provided after each test
- Step-Wise Sequential: FTS, if (-) then STS
- Contingent: FTS, if (-) no STS
29
Q
Management of screening results
A
- Negative Test: Does not exclude possibility of DS, Actual risk report given to pt, no further DS testing recommended
- Positive Test: Actual risk report given to pt; refer to genetic counseling; offer fetal karyotyping (CVS, Amnio)
30
Q
Chorionic Villi Sampling
A
- Obtained from placenta
- Transabdominal or transvaginal
- done at 10-13wk
- Contraindicated in Rh antibodies
- Risk: Fetal loss, infection, bleeding
31
Q
Amniocentesis
A
- Genetic wellbeing
- Fetal lung maturity (later in pregnancy)
- 14-16wk for NT or genetics
- Risk: PROM, Infection, bleeding, PTL, Fetal loss
32
Q
Dates of Prenatal Screening
A
- LMP and Date of Concepton (2wk)
- 3-12wk: US to detect/confirm pregnancy
- 10-13wk: CVS, FTS
- 12-26wk: US to Dx abnormal
- 12.5-15wk: Early amnio
- 15+wk: amnio, fetal Dx, Assess
- 15-20wk: STS (Mother’s multiple markers)
- 16+wk: cordocentesis (PUBS)
33
Q
Changes in levels of HCG, PAPP-A
A
- mother smoker: low PAPP-A
- Multiple Gest: high PAPP-A and HCG
- Increased HCG and PAPP in trisomy defects
34
Q
Ultrasound facts
A
- Abdominal or transvaginal
- Discerns fluid, tissue, bone, fetal activity and vessels
- ALARA Principle: As Low As Reasonably Achievable; Keepsake imaging not encouraged
- Types of US: Standard, specialized, limited
35
Q
1st Trimester US Sights
A
- Gestational/Yolk sac or embryo
- C-R Length
- Cardiac activity
- Fetal number
- Assess embryo/fetal anomaly
- Evaluate uterus adnexa
- Assess fetal neck
- In 1st Tri, US is more reliable for EGA than LMP
- Transvag: fetal heart, gestational age, r/o ectopic/molar pregnancy, measure cervical length, nuchal translucency
