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167 Cards in this Set
- Front
- Back
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When can a CVS be done?
Why not sooner? Why not later? |
10-13+ weeks of gestation
Earlier: Association with limb reduction defects |
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When can an amnio be done?
Why not sooner? Why not later? |
15-20 weeks of gestation
Sooner: Not enough fluid, clubfeet Later: Chance of premature birth |
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*Analytes used in
First-trimester screening *Conditions tested for |
PAPP-A
hCG Down Syndrome Trisomy 18 |
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*Analytes used in
Second-trimester screening *Conditions tested for |
hCG
UE3 AFP Inhibin Down Syndrome Trisomy 18 Smith-Lemli-Opitz Neural Tube Defects/Abdominal Wall Defects |
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Conditions Associated with a Large NT
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Aneuploidies
Including: Down Syndrome Turner Syndrome Trisomy 18 Trisomy 13 [ADD MORE] |
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*What Amnio Can Detect
*Chance for Miscarriage |
*99% chomosome abnormalities
Neural tube defects (look at AFP in amniotic fluid; CVS not do) Abdominal wall defects *<1/300 to 1/500 |
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Chance for miscarriage with CVS
Chance for mosaicism |
<1/300
1-2% |
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Detection rate for CVS
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>99% of chromosome abnormalities
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What screening still needed after CVS?
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Neural tube and abdominal wall defects.
*Quad screen (AFP) at 15-20 weeks. *Ultrasound 18-20 weeks |
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Dates for first-trimester blood draw
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10 weeks to 13.6 weeks
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Dates for NT ultrasound
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11.2 weeks to 14.2 weeks
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Dates for second-trimester blood draw
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15 to 20 weeks (0 days)
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Ultrasound abnormalities leading to level 2 ultrasound
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Choroid plexus cysts
Echogenic bowel Echogenic intracardiac focus Single umbilical artery Dilated renal pelvis Mild ventriculomegaly |
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General Population Risks for:
Down Syndrome Neural Tube Defects Congenital Heart Defects Birth Defect or MR |
1/800 Down Syndrome [TK]
1/1000 NTD 1/100 Heart defect 3-4% Birth defect or MR [TK] |
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Types of Cells Taken in CVS
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*Chorionic villi
2 types of cultures grow: *Direct [add details] *Indirect [add details] |
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Injection given to women having amnio or CVS
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Rhogam to avoid Rh sensitization
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Single Umbilical Artery
Features/Frequency |
Usually:
One vein (oxygen and nutrients to baby) Two arteries (fetal waste to mother's kidneys) SUA: 1/100 (1%) pregnancies |
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Risk Factors for Single Umbilical Artery
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Caucasian
Female fetus Mother >40 Diabetes Multiple gestation (twins) |
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Other Birth Defects More Common with Single Umbilical Artery
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Heart
Kidney Vertebral (Spine) Possible: Slow fetal growth, preterm delivery, stillbirth Look carefully with Level II ultrasound Offer amniocentesis if other findings 3rd-trimester U/S for growth |
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Echogenic Bowel
Features/Frequency |
Looks bright on U/S (dense material)
<1/50 (2%) |
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Reasons for Echogenic Bowel
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Chromosome abnormalities 1/30 (3%)
Cystic fibrosis 1/30 (3%) Fetal infection [LIST THEM; can test for on amnio] Intestinal blockage, atresia Poor fetal growth (if associated with placental bleeding) Other: Reduced movement in intestines Swallowing blood from amniotic fluid Low maternal belly fat |
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Choroid plexus cyst
*What is it? *When seen, and how often? *Associated with what condition? |
Fluid collection in the spongy gland(s) that make cerebralspinal fluid. Can be on one or both sides.
Usually go away by 24-26 weeks. Not harm brain. 1-2% of all babies in second trimester Trisomy 18 (<1% chance) |
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Dilated renal pelvis
(Pelviectasis, pyelectasis, hydrohephrosis) *What characterizes it? *How often seen? *How big to qualify as hydronephrosis? |
Mildly dilated: 5-9 mm
Hydronephrosis: >10 mm Urine backing up into renal pelvis 2-3% of pregnancies |
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Causes of Dilated Renal Pelvis
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Normal variation
Obstruction of the ureter ("Ureteropelvic junction obstruction" most common...up at top) Reflux of urine (faulty valve at bladder) |
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Conditions associated with Dilated Renal Pelvis
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Male babies
Familial kidney problems Down syndrome (more likely if bilateral) |
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Follow-up for Dilated Renal Pelvis
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Level II ultrasound
Amnio if other ultrasound findings 32-week ultrasound to check kidneys After birth: Renal U/S, urine testing If making a normal amount of amniotic fluid, no need for intervention in pregnancy. Surgery rarely needed after birth if improves or remains stable. |
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Factors determining risk of chromosome anomaly
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Mother's age
Blood analytes Ultrasound markers |
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Mild Ventriculomegaly
*Location and size? *Frequency? |
Lateral ventricles 10-15 mm
1/1000 babies Severe ventriculomegaly is called hydrocephalus. |
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What causes Mild Ventriculomegaly?
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Normal variation
Changes in cerebrospinal fluid flow Changes in brain development |
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What Problems Associated with Mild Ventriculomegaly?
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Physical Birth Defects (Heart, Kidney, Spine)
Chromosome Abnormalities 1/25 (4%) Prenatal Infections (CMV, toxoplasmosis interfere with brain development) Genetic Syndromes Brain Development Problems |
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Follow-up to Mild Ventriculomegaly
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Level II ultrasound for other findings
Amniocentesis: *Chromasome abnormalities *Prenatal Infections More concern for learning disabilities/MR if over 12 mm. Gets worse in 1/10 |
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Pregnancy hormones that increase with time
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AFP
UE3 |
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Pregnancy hormones that decline with time
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hCG
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Pregnancy hormones that stay the same over time
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Inhibin
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Down syndrome pattern in first-trimester screening
(Trisomy 18 pattern) |
Hi hCG
Low PAPP-A (Low hCG, Low PAPP-A) |
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Amount of Folic Acid to Take Prenatally
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400 mcg
(4 mg if prior neural tube defect) |
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Gravida_/Para_ _ _ _
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Para: Term, Preterm, Abortion/Miscarriage, Living
Preterm is 24-37 weeks |
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Most accurate ultrasound measurement for dating pregnancy?
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Early measurement of crown-rump length
First trimester (then accuracy decreases) |
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Most common form of twins?
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Dizygotic (two eggs meet two sperm)
Monozygotic is less common: 1/300 |
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What is chorionicity?
Which membrane is closest to the baby? |
The placentation of the embryos
Amnion is first layer around baby Chorion is second layer, attached to uterus monochorionic/monoamnionic inside monochorionic/diamnionic inside dichorionic/diamnionic |
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Rule of thumb for Zygosity vs. Chorionicity
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"Mono is always mono, but di is not always di"
(Monochorionic twins are always monozygotic, but dichorionic twins not always dizygotic) |
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What is a twin peak sign?
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Nice thick membrane separating the sacs, indicates dichorionic/diamnionic and maybe have different genetic makeups
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ACOG recommendations about who gets prenatal options
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Now everyone, not just for maternal age [TKTKTK]
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When is the "all or none" period of pregancy?
(Drugs, alcohol not a risk) |
Before implantation.
First two weeks of embryo development from fertilization to implantation. =First 4 weeks of "gestational age" |
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When do the fetal organs develop?
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3[TKTK]-8 week of embryonic development.
(Heart, CNS, limbs, lips, teeth, palate, external genitalia) Fetal period starts at week 9. |
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What is preeclampsia
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Pregnancy-specific syndrome
Reduced organ perfusion Vasospasm and activation of clotting cascade High BP, protein in urine 3rd Trimester presentation |
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Results of Gestational Diabetes
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BIG BABY >10-11 lbs
Perinatal birth trauma Can get stuck, hypoxia, intellectual deficits Cleft lip and palate [TK] Neural tube defects [TK] |
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Causes of fetal macrosomia (overgrowth)
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Maternal diabetes
[ADD SYNDROMES] |
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Abnormal location or implantation of placenta: What are the risks?
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Fetal growth abnormalities
Cesarean section (placenta previa: low-lying, covering cervix) Hemorrhage (placenta [acretta/incretta/percretta]: embeds in scar of former c-section, muscles of uterus can't clamp down vasculature to stop bleeding after birth) |
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Causes of preterm labor (<37 weeks)
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Infection/inflammation
Bleeding Uterine anomalies Multiple gestations Idiopathic 30-50% recurrence rate in future pregnancy |
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What is the length of a term pregnancy?
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37-42 weeks
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Risk to fetus of preterm delivery (and what treatment?)
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Give steroids to mature lung development (24-48 hours)
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When does twin-to-twin transfusion happen?
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Monochorionic twins share a blood system
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First Trimester Cutoff for Down Syndrome
Final Cutoff for Down Syndrome |
1/100
1/200 (If just quad marker, 1/150) |
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First Trimester Cutoff for Trisomy 18
Final Cutoff for Trisomy 18 |
1/50
1/100 |
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Serum Integrated Screening
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First trimester blood test (10 weeks-13 weeks 6 days)
+ second trimester blood test (15 weeks-20 weeks) |
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Sequential Integrated Screening
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First + Second Trimester Blood Test
Plus NT |
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Omphalocele vs. Gastroischesis
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Both are abdominal wall defects, involve intestines protruding from the abdomen
In Omphalocele, a thin membrane covers them. (Most common in teen to early-twenties mothers) |
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Omphalocele is a type of Umbilical Hernia
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Most common in African Americans
Associated with: MPS storage diseases, Beckwith-Wiedemann syndrome, Down syndrome 25 - 40% of infants with an omphalocele have other birth defects such as congenital diaphragmatic hernia, heart defects, genetic syndromes |
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Screen positive for SLOS
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Increased risk for SLOS:
Risk is >1 in 250. > 1/250 Also called SCD SLOS, Congenital anomalies or Fetal Demise. |
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AFP cutoffs for NTD in second trimester
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Screening cutoffs:
>2.5 AFP MoM (for single fetus) >4.5 AFP MoM (for twins) |
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Which pregnancies are not screenable?
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Fetal reduction
Fetal demise >8 weeks gestation More than 2 fetuses (Fetal reduction <8 weeks gestation, 1st trimester specimen is not valid) |
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Down syndrome pattern in second-trimester screening
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hi hCG
hi Inhibin lo AFP lo UE3 Could be overestimation of gestational age (fetus is younger than we thought) |
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Redating if screen positive?
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Yes for DS, may be overestimation of gestational age
Don't redate for T18 due to IUGR. May not be accurate to redate |
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What could be the cause of a high AFP?
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Underestimation of gestational age,
multiple gestation, fetal demise, placental abnormalities, normal variation High AFP signals a high risk pregnancy even if no NTD found: Low birth weight Preterm delivery Fetal demise |
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Analytes for Smith-Lemli-Opitz syndrome (SLOS)
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Very low UE3
Low AFP, hCG Can't calculate for more than one fetus |
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Factors used in serum screening calculation
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Age
Race Weight Smoker? |
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Detection rates of Quad screening alone
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80% Down syndrome
70% Trisomy 18 80% spina bifida (97% anencephaly) 85% abdominal wall defects 60% SLOS |
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Detection rates of full Sequential Integrated screening (with NT)
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90% Down syndrome
80% Trisomy 18 80% spina bifida (97% anencephaly) 85% abdominal wall defects 60% SLOS |
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Detection rates of Serum Integrated screening (2 blood tests)
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85% Down syndrome
80% Trisomy 18 80% spina bifida (97% anencephaly) 85% abdominal wall defects 60% SLOS |
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Smith-Lemli-Opitz syndrome
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Can't make cholesterol normally
DHCR7 enzyme deficiency 1/60,000 Multiple congenital malformations Enlarged ventricles Hypoplastic or absent corpus callosum Mental retardation Physical birth defects: Microcephaly, bitemporal narrowing Ptosis Short nasal root, anteverted nares Hypospadias Global developmental delay Failure to thrive Ambiguous genitalia Cleft palate Congenital heart defect Kidney abnormalities Polydactyly 2/3 toe syndactyly Cataract or micropthalmia Strabismus, nystagmus |
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ACMG recommends screening for which AJ disorders?
ACOG recommends which? |
TKTKTK
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Spinal Muscular Atrophy
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TKTKTK
Deletion in SMN1 SMN2 gene copies can partially compensate (less severe) Problem with motor neurons (anterior horn cells) Brain normal Progressive weakness Problems breathing, swallowing Least common in African Americans |
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Risk of a second aneuploidy
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1% or age-related risk, whichever is higher
Takes into account gonadal mosaicism (which is 1/2000 in young people who have aneuploid pregnancy) |
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Maternal cell contamination testing--how done?
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Look at 9 different polymorphic areas in the genome
Number of repeats Make sure fetal is different from maternal (only inherited one of maternal markers at that locus) |
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What if there is Maternal Cell Contamination (MCC) in amnio?
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Can culture the cells. Maternal blood cells are not favored in culture
NOT TRUE in CVS. Cultures favor both so have to re-dissect |
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What percentage of T21 pregnancies have normal ultrasound?
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50%
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What disorders cause increased NT?
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<2 mm is normal
Trisomies (21, 18, 13) Turner syndrome Triploidy Lymphadema May be due to cardiac abnormality |
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Second trimester ultrasound
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Still need this after serum screening to evaluate for birth defects
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What if see MCV<80?
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Microcytic anemia
Suspect thalassemia Do hemoglobin electrophoresis Then molecular testing |
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African-American screening concern?
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Sickle cell anemia
Hemoglobin electrophoresis to id Hemoglobin S |
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Spinal Muscular Atrophy (SMA) carrier frequency
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1/50
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What if did PGD?
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Confirmation by amnio recommended
(5-10% false + or false - rate. Maybe just didn't see the FISH signal) |
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Most common inherited cause of childhood death?
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Spinal muscular atrophy (SMA)
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Features of SMA
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Alert, cute face
Destroys nerves for voluntary movement Intelligence normal Affects: Breathing, swallowing Head and neck control No cure or treatment |
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Klinefelter Syndrome
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47,XXY (Barr body)
1/500 - 1/1000 males Hypogonadism (small, firm, fibrotic tubules; small penis) Infertility/impaired spermatogenesis Androgen deficiency Increased FSH, LH Gynecomastia RISK FOR BREAST CANCER Tall stature, long limbs, eunichoid Learning disabilities (language, speech delay) Elbow dysplasia, scoliosis Inadequate virilization at puberty |
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What is the most common sex chromosome abnormality?
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Klinefelter Syndrome
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Causes of Klinefelter Syndrome
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53% PATERNAL MEIOSIS I ERROR
34% maternal meiosis I error 9% maternal meiosis II Maternal age effect with meiosis I error NO PATERNAL AGE EFFECT |
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Genetic conditions attributed to the father
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Klinefelter syndrome
(50% Paternal Meiosis I) No paternal age effect Achondroplasia |
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47,XYY
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Frequency 1/1000 males
Paternal meiosis II nondisjunction (get 2 Y's) NO PATERNAL AGE EFFECT Normal fertility Learning disabilities in speech, language, reading Distractible, hyperactive, frustrateable Increased growth velocity in early childhood Tall, lanky |
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Turner syndrome
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1/2500 45,X and others
>90% miscarry Paternal X more likely to be missing NO MATERNAL AGE EFFECT Short stature Streak gonads, ovarian failure, infertility Cystic hygroma, webbed neck Low posterior hairline Broad chest, widely-spaced nipples IUGR Newborn lymphedema Cardiac, renal defects Skeletal anomalies (Elbow deformity, short IV metacarpal) Delayed puberty or amenorrhea (10% spontaneous puberty) Brown nevi Impaired spatial perception, mathematics, ability to form goals Risks: Hypertension, Hearing loss Hypothyroid, glucose intolerance Obesity |
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Heart issues in Turner syndrome
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Left-sided:
Bicuspid aortic valve Coarctation of the aorta Hypoplastic left heart Mitral valve prolapse Aortic root dilation in 3-8% Can lead to dissection Risk of hypertension |
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Renal issues in Turner syndrome
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1/3 have structural malformations
Horseshoe kidneys Double collecting system Hydronephrosis Renal US recommended |
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Hearing issues in Turner syndrome
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Recurrent otitis media
Progressive midfrequency hearing loss |
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Which Turner karyotype associated with MR?
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46,X,r(X) if the ring is small
Missing X inactivation center Not express XIST at Xq13 |
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What karyotype can range from female to ambiguous genitalia to normal male?
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45,X/46,XY
If diagnosed prenatally, 90-95% will be phenotypically male |
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47,XXX
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1/1000 females
Phenotypically normal Tall, thin Normal puberty and fertility Poor coordination, awkwardness Delayed motor milestones Language, verbal, reasoning, math deficits |
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Turners karyotypes
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50% 45,X
15% 46,X,i(Xq) 15% 45,X/46,XX Other types ~5% each |
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What is the recurrence risk for spina bifida, and what raises risk the most?
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2-3% after one affected child (was 1/1000 before)
Having a parent with spina bifida (even occulta) increases risk more than anticonvulsants, etc. 2-3% recurrence risk |
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Is ultrasound a useful tool for recalculating Down Syndrome risk?
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Large NT, yes
Second trimester, no 50% of DS babies have a normal ultrasound |
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What screening test can you repeat?
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Hi AFP signalling risk for NT defect
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Second-trimester US more likely to detect abnormalitites in T21 or T18?
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T18: 80%
T21: 50% |
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Where is inhibin-A produced?
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In the placenta
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What test do you order if an NT is above 3 to 3.5?
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Fetal echocardiogram
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Association between maternal age and AFP levels?
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No
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L1 syndrome
Aqueductal stenosis |
L1CAM neural cell adhesion molecule
X-linked inheritance Phenotypic spectrum includes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS) MASA syndrome (mental retardation, aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs) SPG1 (X-linked complicated hereditary spastic paraplegia type 1) X-linked complicated corpus callosum agenesis Males with HSAS: Severe hydrocephalus Adducted thumbs Spasticity Severe MR |
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IQ associated with MR
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<70
Mild (IQ: 50-70) Moderate (IQ: 30-50). |
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If an affected sib has delta F508 CF mutation and another that can't be identified, what is chance of unaffected sib being a carrier if had a NEGATIVE panel?
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Don't Bayes it out
NEGATIVE panel means don't carry delta F508 50% chance carry the unidentified mutation |
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Advanced paternal age-risks
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New gene mutations
Autosomal dominant Large number cell divisions in spermatogenesis Single base pair substitutions Rate higher in men than women FGFR2, 3 RET genes Pfeiffer syndrome Crouzon syndrome Apert syndrome Achondroplasia Thanatophoric dysplasia MEN2A MEN2B NF1 a lesser association OI Retinoblastoma Maybe schizophrenia, autism |
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Teratology
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Drug
Chemical Infection Pollutant Interferes with normal development |
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Principles of Teratology
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Mechanism
Dosage Timing Agent Genotype |
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Types of abnormal development
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Malformation
Deformation (outside forces) Disruption (breakdown of normal tissue) Dysplasia (abnormal cell organization in a tissue) |
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All or none period
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To day 11 or 12 of embryogenesis
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Primary infections-Types
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TORCH
Toxoplasmosis Other (Varicella, Syphillis, Parovirus) Rubella (hearing) CMV (hearing) Herpes |
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Congenital CMV
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"Blueberry muffin spots"
Extramedullary hematopoesis In herpesvirus family 1/20,000 births Most infections silent (5-15% later develop hearing loss, MR, etc.) 10% show signs at birth Microcephaly MR Sensorineural hearing loss Chorioretinitis Seizures Intracranial calcifications Hepatosplenomegaly Thrombocytopenia IUGR 30% mortality |
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Toxoplasmosis
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Parasite, stage in cats
24-30 weeks worst time to be exposed Signs: Ventriculomegaly Amniotic fluid PCR Chorioretinitis Intracranial calcifications MR Microcephaly Spenomegaly Growth retardation |
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Radiation
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DOSAGE >5 rads
Chest x-ray is 60 millirads You worry about whole-body CT (MRI no radiation) Microcephaly Growth retardation possible MR I131 70 days post-conception concentrates in fetal thyroid and ablates it Hypothyroidism Thyroid hormone needed for brain development |
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Fetal Alcohol Syndrome
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Prenatal onset growth retardation (persists)
Facial anomalies: Microcephaly Structural brain abnormalities Short palpebral fissures Flat midface Indistinct, SMOOTH philtrum Thin upper lip Epicanthal folds Short nose Micrognathia Neurocognitive defects HOCKEYSTICK palmar crease (1/2 fingers) Williams syndrome also a long, smooth philtrum |
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Anticonvulsants
(Tegretol/Carbamazepine Phenytoin Valproic Acid) |
Folic acid inhibitor
Neural tube defects TAKE WITH 4 MG FOLIC ACID 1/100 (as opposed to 1/1000) Cleft lip and palate Heart defects Urinary tract defects Fingernail hypoplasia Microcephaly Epicanthal folds Short nose, long philtrum Upslanting palpebral fissures |
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Lithium
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(Lynne something wrong with heart)
1-5% heart defects Ebstein's anomaly Abnormal formation of tricuspid valve ASD |
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Warfarin/Coumadin
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(Clotting is blood and bone)
Skeletal anomalies Stippled epiphyses Nasal hypoplasia CNS anomalies HEARING LOSS IUGR Congential heart disease |
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Thalidomide
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Limb reduction defects
Heart defects Esophageal atresia Duodenal atresia Anomalies of external ear |
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Methotrexate/Aminopterin
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Used for chemical abortion
Rheumatoid arthritis Folic acid antagonist Clover-leaf skull Limb defects CNS abnormalities Neural tube defects |
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Maternal PKU
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Phenylalanine levels rise
Phenocopy of fetal alcohol syndrome MR Growth deficiency (pre- and post-) Microcephaly Epicanthal folds Short palpebral fissures 15% cardiac defects Behavioral problems Oral clefting |
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Which 2 teratogens are phenocopies?
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Maternal PKU
Fetal alcohol syndrome |
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Maternal diabetes
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Uncontrolled:
BIG BABY high birth weight 3 to 4x risk Up to 20% birth defects Neural tube defects Oral clefting, Microtia Heart defects Skeletal defects Urinary, reproductive, digestive systems Order U/S, amnio, fetal echo at 20-22 weeks |
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Maternal lupus
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Fetal heart block
Aplasia cutis |
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Maternal hyperthermia
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>102 degrees core temp
Fever, hot tub Neural tube defect |
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Resources
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Reprotox
Teris Shepard's CTIS |
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Adverse pregnancy outcome
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When 2 or more abnormal quad screen markers
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Ichthyosis
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Severe congenital forms are
Autosomal recessive Multiple genes involved Harlequin ichthyosis Born prematurely Encased in thick, hard, armor-like plates of cornified skin Severely restrict movement Life-threatening complications Respiratory distress Feeding problems Systemic infection Collodion babies: Born with taut, shiny, translucent or opaque membrane encases entire body, lasts for days to weeks. |
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MZ vs DZ twin proportions
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1/3 mono
2/3 di |
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Recurrence risk for T21?
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1% or mother's age-related risk
Overall risk 1/600 to 1/800 |
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Down syndrome physical features
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40-50% Congenital heart disease
Endocardial cushion defects: AV canal, VSD, ASD Mitral valve prolapse PDA Tetralogy of Fallot Hypotonia Joint hyperflexibility Brushfield spots (iris speckling) Nuchal folds Overfolded helix Brachydactyly 5th finger clinodactyly Single transverse palmar crease Sandle toe (1st & 2nd) Hypoplastic nipples, breast buds Otitis media 60% have some hearing loss Vision problems, cataracts |
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Other T21 risks
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GI disorders at birth:
Duodenal atresia Hirschprung's Meckel's diverticulum Hypothyroidism 15% Atlantoaxial instability 10% Leukemia 1% |
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Neurodevelopment in T21
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Mild MR (50-70)
to Moderate MR (35-50) Receptive better than expressive language Seizures in 5-7% Early-onset Alzheimer's |
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6 Results of parental Robertsonian translocation (14;21)
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Normal
Balanced Trisomy 21 Trisomy 14 Monosomy 21 Monosomy 14 |
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What are the T21 risks for these ages?
30 35 40 45 |
1/700 age 30
1/300 age 35 (any abn: 1/134) 1/86 age 40 (any abn: 1/40) 1/22 age 45 At age 37 you get above 1/200 At age 40 get above 1/100 |
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How is spina bifida detected?
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On ultrasound
See lemon sign Banana sign in cerebellum Can't usually see the bulge itself |
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When do you repeat a serum AFP?
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When <3 MoM
If still high, do an amnio Amnio, but not CVS, is Informative about NT defects |
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Analyte in Turner's syndrome?
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High hCG
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What can high AFP be caused by?
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Oligohydramnios
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Analytes with IUGR?
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Low AFP, UE3, hCG
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Very high AFP associated with what?
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Kidney problems
Fetal demise |
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Remember an older woman might screen positive for DS simply due to her age
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Could be a healthy baby if analytes look okay
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What testing do for a prior NT defect?
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Amnio
AchE and AFP |
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Male infertility
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XXY MOST COMMON CAUSE
15% with azoospermia 2% with oligospermia AZF microdeletion (Yq11) 13% of azoospermic 6-8% of oligospermic AZFc most common (60%) Deletions, mutations in SRY/DAX1 |
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Premature ovarian failure in what syndromes?
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Turner
Fragile X Galactosemia and others |
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Background risk for birth defects
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3-4%
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Recurrence risk for neural tube defects
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1-2%
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MTHFR C677T mutation
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Increases homocysteine
Increases neural tube defect risk IF In bottom 25% of folate intake |
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How much do
Heart/structural defects/cystic hygroma/ventricuar dilation or Nuchal thickenin >5mm Increase T21 risks? |
Nyberg:
25x 18.6x Others are 5x or less: Echogenic bowel Short humerus or femur EIF |
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When is a pregnancy not screenable?
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More than 2 fetuses
Fetal reduction Demise after 8 weeks gestation |
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If screen positive for NTD or Down syndrome, when recalculate AFP result?
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Gestational age off by 14 days
T18 no changes allowed unles over 14 days and was "too early" so redraw |
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How many fetuses have choroid plexus cysts?
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1/50
Normal or T18 70% T18 at midtrimester will miscarry before birth |
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XYY recurrence risk in their children?
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No increased risk
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NT measurements and risk of chromosome defects
(also raises risk of fetal demise, major abnormalities) |
<95th centile: 0.2%
95-99th centiles of normal: 3.7% 3.5-4.4mm: 21% 4.5-5.4mm: 33% 5.5-6.4mm: 50% >6.5mm: 65% |
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Congenital heart disease
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Recurrence risk to sib of isolated case:
2-3% Offspring of isolated case Father: 2-3% Mother: 5-6% If two affected first-degree relatives: 10% |
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Factors ask about in maternal serum screening
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Weight
Maternal age Smoking (last 7 days) Insulin-dependent diabetes Number of fetuses Gestational age Race or ethnicity |
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Tetralogy of Fallot
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Pulmonary stenosis
VSD Overriding aorta Hypertrophy of right ventricle |
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Fetal demise maternal serum pattern
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Very low uE3
Very low hCG AFP variable |
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Turner syndrome maternal serum pattern
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very low uE3
high hCG if hydrops low hCG if no hydrops |
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When to do a dating ultrasound?
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After 7th week
Crown-rump length 7-12 weeks Biparietal diameter after 12 week |
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3 or more birth defects and MR, how likely to have a chromosome abnormality?
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5.5%
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Very low UE3
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SLOS
X-linked ichthyosis CAH Anencephaly |
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Fetal hydantoin syndrome
Dilantin anticonvulsant |
Clefting
Nail hypoplasia MR Facial features |
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Triploidy serum marker?
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Low hCG
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