MFM Flashcards
When is AFP checked
Between 15 and 22 weeks gestation
High AFP causes
Open NTD
GI abn (liver necrosis, esophageal or intestinal obstruction, omphalocele, gastroschisis)
Renal abn
Masses
Multiple gestation
If unexplained elevation - ^risk of IUGR or fetal death
Low AFP causes
Trisomies
Fetal death
Inaccurate GA
Gestational trophoblastic disease
First trimester maternal screen
At 10-13 weeks
PAPP-A
B hCG
Combined with maternal age - detects 60-65% T21
+ nuchal translucency 10-14 weeks
Mat age + PAPP A + BhCG + NT detects 78-89% of T21 and 91% of T18
Abn nuchal translucency risk of aneuploidy
1 in 6
Normal is 0.5mm-2mm; >3mm is abn
Explanations for nuchal translucency:
Cardiac failure
Extracellular matrix abn
Abn lymphatic system
Hygroma testing
50% chance aneuploidy
If euploid 50% with major fetal malformation
If found -> get details US, fetal echo, offer CVS
Quadruple screen
14-20 weeks
AFP
Mat unconjugated estriol
BhCG
Inhibin A
Low AFP, high BhCG, low uE3, high inhibin A
T21 on quad
Detects 75-81%
Low AFP, low BhCG, low uE3, normal inhibin A
T18 quad
Detects 60%
T13 quad
Not helpful
Cell free DNA - obtained when & indications
9 weeks GA
Screening test
^ aneuploidy risk
RhD genotype
Sex identification in X-linked genetic disorders
Risk of CAH
Smith-Lemli-Opitz
Prenatal screen
Low uE3, low AFP, low bhCG
Turner syndrome quad screen
Low AFP, high BhCG, low uE3, high inhibin A if hydrops, low inhibin A if no hydrops
Timing of amnio, CVS, and PUBS
Amnio 15-20 wk
CVS 10-13 wk
PUBS >19 wk
Teratogenic effects:
ACEI
Greatest risk in 2nd & 3rd tri
Oligo, skull hypoplasia, renal tubular dysgenesis
Postnatal hypotension and oliguria
Teratogenic effects:
Alcohol
Worse earlier in gestation
Worse with greater amounts less frequently than chronic small amounts
Abn in 3 areas: physical, growth, neurodevelopment
Teratogenic effects:
Carbamazepine
Craniofacial defects, fingernail hypoplasia, growth restriction
NTD, developmental delay
Decreased placental transfer of vit K
Teratogenic effects:
Cocaine
Placental abruption
Cutis aplasia, porenchephaly, ileal atresia, cardiac abn, fetal growth restriction, GU abn
Teratogenic effects:
Cyclophosphamide
Exposure early in pregnancy
Missing or hypoplastic digits, cleft palate, single coronary artery, imperforate anus, growth restriction, microcephaly
Teratogenic effects:
Phenytoin (hydantoin)
Digit and nail hypoplasia, cleft lip/palate, IUGR, FTT, wide anterior fontanelle, hernias, dec placental vit K transfer, maybe cardiac abn (PS, AS, VSD)
Teratogenic effects:
Retinoic acid
1st tri exposure
Cardiac: TGA, TA, TOF, VSD, DORV, IAA, retroesophageal subclavian artery
Microtia, hypertelorism, triangular facies, facial nerve palsies, limb reduction, hydrocephalus, thymic and parathyroid abn
Teratogenic effects:
Lithium
Ebsteins anomaly
Teratogenic effects:
Methotrexate
6-8 weeks after conception exposure
Cranial dysplasia, broad nasal bridge, low set ears, micrognathia, microcephaly, IUGR
Teratogenic effects:
Phenobarbital
Cleft lip/palate, cardiac abn, decreased placental transfer of vit K
Teratogenic effects:
Salicylates
Risk thrombocytopenia
Intrauterine closure of PDA, PH
Teratogenic effects:
Valproic acid
NTD, long thin fingers, hyperconvex nails, narrow bifrontal diameter, anteverted nostrils, midface hypoplasia, cardiac (CoA, hypoplastic left heart, AS, IAA, ASD, PA w/IVS)
Teratogenic effects:
Warfarin
Exposure 6-12 weeks GA
Nasal hypoplasia, mental deficiency, seizures, stippled bone epiphyses
Heparin does NOT cross the placenta
Symmetric IUGR/SGA
HC proportional to rest of body
Early onset (prior to 3rd trimester)
Risk of perinatal depression is low
Blood flow to ICA is normal
Normal glycogen fat and glucose stores
Etiology: Usually intrinsic, results from chromosomal abnormalities, congenital infections, and some IEM
Asymmetric IUGR/SGA
HC % greater than weight %
Onset 3rd trimester (but can develop between 16-32 weeks as well)
Risk of perinatal depression is increased
Blood flow to the ICA is increased (thus the brain growth is spared)
Low glycogen and fat stores so an increased risk of hypoglycemia
Etiology: usually environmental, results from uteroplacental insufficiency from preE, cHTN, or severe maternal DM
Neonatal effects of IUGR
Depressed immune system (decreased lymphocyte number and function and decreased Ig levels)
Hyperglycemia (bc of low insulin and increased catecholamines)
Hypoglycemia (bc of low stores)
Hypothermia
Hypocalcemia (bc of decreased vascular supply in utero)
Perinatal depression (bc of acute on chronic stress)
Polycythemia (bc of chronic hypoxemia)
Mortality risk 5-20x greater than AGA counterpart
Mechanism of hydrops
Congestive heart failure (most common)
Anemia
Lymphatic obstruction
Decreased plasma on osmotic pressure with increased capillary permeability
Postnatal management of NI hydrops
See what’s been performed.
Chromosomal analysis, metabolic studies, CBC, blood type, Hb electrophoresis, skeletal X-rays, echocardiogram, US of abdomen and chest, genetics evaluation
Range for uterine artery gas
7.4/32/95 sat 98%
Range for Uterine vein gas
7.34/40/40 sat 76%
Range for umbilical vein gas
7.35 (7.25-7.45) / 38 (26-49) / 29 (17-40) sat 68%
Range for umbilical artery gas
7.28 (7.18-7.38) / 49 (32-65) / 18 (5-30) sat 30%
Non immune fetal hydrops
- Disorders a/c CHF (most common)
- Anemia
- Obstructed lymphatic flow
- Decreased plasma osmotic pressure with increased capillary permeability
(Heme: TTTS, homozygous alpha thal, rbc enzyme deficiencies, severe fetomaternal hemorrhage;
Cardiac: arrhythmia, CHD, cardiac mass, cardiomyopathy;
Vascular malformation: AVM, vascular accident, lymphatic obstruction;
Infection: coxsackie, parvo, CMV, syphilis, toxo, rubella, herpes, adenovirus;
Genetic: aneuploidy, syndrome;
Metabolic: LSD, GSD type IV;
Endocrine: thyrotoxicosis;
Pulmonary: chylothorax, CPAM, pulmonary sequestration;
Other: congenital nephrotic syndrome, CDH, skeletal dysplasia, placental/coed abnormalities)
Causes of neonatal withdrawal
Narcotics
Barbiturates
Stimulants
Depressants and sedatives (like alcohol)
SSRI
Timing of symptoms narcotic withdrawal
Heroin within 48 hours
Methadone within 48-72 hours and symptoms can last for 4-6 months
CNS, ANS, GI, Resp symptoms
Timing of symptoms barbiturates
DOL 4-7
Acute (irritable, crying, no sleep, tremors, hiccups) and subacute stage (voracious appetites, reflux, gagging, irritable, sweating, sensitive to sound, poor sleep)
Timing of symptoms for stimulants
Within 72 hours
Symptoms due to drug toxicity rather and withdrawal so symptoms are stimulant symptoms
Timing of symptoms for depressant and sedatives
Ethanol 3-12 hours (initial ~72 hours hyperactive and irritable and then lethargic phase for ~48 hours)
Sedative or hypnotic meds usually not until after few days
Timing of symptoms for SSRI
Within 48 hours and resolve within 48 hours
Symptoms in 1/3 of neonates exposed
Tremors, hypertonic, sleep disturbance, GI disturbance, high pitched cry
Can have PH (poor neonatal adaptation)
