Thrombophilias, thyroid disease, autoimmune disorders, genetic screening Flashcards
Prevalence of Factor V Leiden
8% in Caucasians
How often is “thrombophilia panel” positive in normal, healthy people?
40%
Should thrombophilia testing be done for adverse pregnancy outcomes?
NOPE (not related except APLS)
Criteria for APLS
1 clinical + 1 lab:
Vascular thrombosis, fetal death 10 wga or greater, sPEC or FGR requiring delivery < 34 wga, at least 3 SABs > 10 wga
Lupus anticoagulant, ACA IgG or IgM, anti-beta-2-glycoprotein (>12 wks apart)
Risks other than fetal loss associated with APLS
FGR, gHTN / sPEC, indicated PTD (each about 33% risk)
Risk of thrombosis in pregnancy with APLS
5-12%
Anticoagulation for APLS in pregnancy
Ppx + baby ASA antepartum
Ppx x 6 wks postpartum
Fetal surveillance for APLS
Serial US, NST starting at 32 wga, del by 39 wga
Estrogen impact on thyroid levels
Increases binding proteins like TBG and albumin so that no change in free hormone level (but total increased to compensate!)
hcg and TSH receptor
hcg stimulates TSH receptor (ie. appears to have hyperthyroidism, esp in hyperemesis)
Most common cause of hyperthyroidism in pregnancy
Graves disease (thyroid-stimulating immunoglobulins - TSI - stimulate thyroid receptor)
Scary risk related to thyroid storm
CHF
Treatments for thyroid storm
PTU (1000 mg then 200 mg q6hrs)
Sodium iodide (500-1000 mg q8hrs)
Dexamethasone (2 mg q6hrs x4)
Propanolol (or labetalol or esmolol)
Most common causes of hypothyroidism
Hashimoto (autoimmune) thyroiditis, iodine ablation or surgery, iodine deficiency
Synthroid requirements in pregnancy
Increase 50-100%
Effect of rheumatoid arthritis on pregnancy
None (not even baseline proteinuria)
Treatments for RA in pregnancy
Glucocorticoids, short-term NSAIDs, TNF-a blockers
Risks of SLE in pregnancy
SAB, IUFD, FGR, PTB (indicated), PPROM, complete heart block
Risk of IUFD with SLE + APLS
With APLS 50% risk
With APLS and prior IUFD 85% risk
If anti-SSA, anti-SSB in pregnancy, then…
Fetal echocardiogram in 2nd trimester
Treatments for SLE in pregnancy
Hydroxychloroquine, steroids, azathrioprine (for more severe dz, risk of FGR), NSAIDs
Multiple marker screening GA time windows
First trimester 11-14 wga
Second trimester 15-22 wga
AFP high in MMS
Neural tube defect
Hcg or inhibin high in MMS
Down syndrome
All MMS markers low
Trisomy 18
Next step if abnormal NT
Automatic positive -> genetic counseling and diagnostic testing
cffDNA and PPV
Lower PPV at lower age
CVS: when and risk
10-13 wga, loss rate 1:455
Amnio: when and risk
15-20 wga, loss rate 1:900
Cystic hygroma probability of different outcomes
50% karyotype abnormalities
25% structural abnormalities
25% apparently normal
(cystic hygroma = automatic positive screen)
Likelihood of Down syndrome with ventriculomegaly
25 x increased risk
Atrioventricular septal defect
Virtually diagnostic of Down syndrome (half of DS will have cardiac defect)
Duodenal atresia differential diagnosis
Duodenal web vs annular pancreas
How many of duodenal atresia have Down syndrome?
33%
Duodenal atresia associated finding
Polyhydramnios
Most common chromosomal abnormality with omphalocele
Trisomy 18 (1/3 have karyotype abnormality)
Measurement for thickened nuchal skin fold
> 6 mm at <20 wga
Down syndrome risk with thickened nuchal skin fold
Increases 10-20 fold (1/3 of Down syndrome cases have this)
Chromosome abnormality: ventriculomegaly, EIF, cardiac defects, duodenal atresia, short HL and FL, echogenic bowel, mild pyelectasis, sandal sign
Trisomy 21
Chromosome abnormality: choroid plexus cysts, posterior fossa abnormality, clenched hands, cardiac defects, omphalocele, club / rocker bottom feet
Trisomy 18
Chromosome abnormality: midline craniofacial abnormality, cardiac defects, neural tube defects, severe FGR
Trisomy 13
US signs of NTD
Banana sign, lemon sign, ventriculomegaly, spinal defect, meningomyelocele
Marker to screen for NTDs
MSAFP
