Last minute Flashcards
What paper talks about oocyte development
MacLennan et al
- crossover at chiasmata
- dictyate stage
- chiasmata hold sister chromatids together
- hromonal stimulation induces groups of dictyate to mature
- links at chiasmata allow tension to be generated when centromeres from each homolog attach to spindle fibres
- failure to form crossover can lead to segregation error
(30% maternal aneuploidies)
Age, maintaining chiasmata and sister chromatid cohesion becomes and issue
Position of chiasmata can predispose to missegregation
75% of downs due to missegregation of homologues
Fewer crossovers - 1
More peri-centromeric crossovers
What paper talks abot foetal surgey
Maselli and Badillo
> 80% common develop before the 12th week
3D USS developed
-craniofacial, nueral tube, skeletal defects
4D
- congenital heart defects
- valve regurge, ejection fraction
Allows assesssment of foetal myocardial function
Guided USS
- laser ablation in TTTS
- higher percentage with non functional deficits
EXIT
- Low transverse incision
- pumped with ringers solution to maintain uterine volume and prevent contraction
- ABX bolus
- Balloon decompressed at 34 weeks by USS guidance
- Increased survival from 24-54% in previous studies
- no sig diff in this study
What paper talks about epigenetics and twinning
Poulsen et al
Increasing evidence that phenotypic discordance in MZ twins not just due to postnatal environmental factors but also prenatal environmental factors, postzygotic genetic and epigenetic factors
Elderly MZ twins show considerable tissue variation
Difference in gene expression 4x elder-younger
Type 2 diabetic twin, significantly lower birth weights
What paper talks about foetal alcohol syndrome
Gupta et al
Alcohol linked to apoptis of NCC
Neuropyschiatric effects of FAS - serotenergic neuron apoptosis in mice
Functional imaging has shown lower serotonin in cortex in children
Ethanol diffuses rapidly and distributes rapidly into foetal compartment
Slower elimination rate
Accumulation
Oxidative stress
decreased concentration of foetal metabolic enzymes
Free radicals due to metabolism
-uncontrolled apoptosis in foetal brain
Ethanol also causes rapid placental vasoconstriction
-inhibits transport of critical cofactors necessary for growth
Risk of FAS
- timing
- amount of alcohol
Reversal
- antioxidant e.g. vit C
- mixed evidence
- may be adverse effects like low birth weight
- folic acid
- boric acid
Stem cells
- a recent paper showed foetal rat brain derived stem cells reversed actions of EtOH on gabanergic neurons
- Reversed memory impairment and cognitive function
- risk of teratoma
What paper talks about placenta previa
Silver 2015
Which paper talks about defective implantation
Norwitz ER
Many pregnancy related complications have origin in implantation and placental development
excessive invasion
-accreta
Inadequate
-restricted endovascular invasion - preeclampsia
Molecular mechanism unknown
Injection of prostaglandins into the uterus –> abortion
Uterine prostaglandin synthesis inhibited
Who talks about Myelomeningocoele repair
Adzick et al
Primary outcome
- foetal/neonatal death or need for shunt
- 68% (foetal surgeru) vs 98% (post natal)
- shunt placement 40vs82% at 12 months
- prenatal improved mental development and motor function significantly at 30 months
Who talks about prenatal screening
Norton et al 2015
15,841 women
cfDNA
trisomy 21 detected in 100% vs 79%
Lower false positive rates (0.06 vs 5.6%)
Can detect some sex chromosomes aneuploidies
less sensitive than combined test
combined test can identify more anomalies
