GENETICS SG Flashcards
study guide questions
what are high-risk HR pregnancies?
- Corrected & non-corrected heart dx
- Cystic fibrosis
- Severe DM
- Severe asthmatics
who can become HR pregnancy?
- PTL/PROM * trauma related injuries, DIC
- pneumonia * placenta abnormalities
- PE/E, HELLP * multiple gestation
Cardiac Disease in pregnancy
- Rheumatic fever: (@50%, but now requiring 2* antibiotics
- mitral valve prolapse (very common)
- congenital heart defects - corrected & non-corrected T of F
- cardiomyopathies - many are pregnancy-induced
- dysrhythmias
how pregnancy influences cardiac system?
increase CO (40-50%) with peak @ 32-34 wks - then further increase during labor (may be as high as 10L during labor)
45% increase in bld vol - also helps at time of delivery as protective mechanism
hormonal influence –> vasodilation, increased peripheral resisitance
what are the classification in cardiac disease?
Class I: asymptomatic
Class II: symptomatic with increased activity
Class III: symptomatic with ordinary activity
Class IV: symptomatic at rest
chronic cardiac disease maternal effects?
increases oxygenation loss of function pulmonary edema dissecting aneurism pulmonary hypertension cardiac failure
what is the biggest cardiac risk during labor? for MOB with cardiac disease
pulmonary edema
chronic cardiac disease and fetal effects?
Fetal hypoxia FGR Fetal distress Mental retardation increase risk of cardiac anomaly (50%)
diabetes in pregnancy causes what maternal effects?
increased insulin production
increased peripheral resistance to insulin
increased antagonistic effect from hormones
“Diabetogenic State”
how GDM develops?
pancreatic B-cell fnc is impaired in response to increased stimulation & induced insulin resistance in pregnancy; 24-28 weeks
DM and maternal effects?
SAB/spontaneous abortion? PE/Eclampsia PTL Polyhydraminos Infection
maternal hyperglycemia effect on fetus?
- congenital anomalies
- macrosomia
- delayed lung maturity: increased BS interferes with PG (phosphyatidylglycerol) production, therefore mature fetal lung surfactant may not be present until 38-39 wks
GDM effect on fetus?
Anomalies & related sequalae Birth trauma Prematurity Hypoglycemia Hyperbilirubinemia Learning Disabilities Childhood obesity & Type II Diabetes
maternal thyroid disease
Thyroid hormones (T3 & T4) does not cross the placental barrier
Fetal thyroid synthesizes its own hormones (10 weeks)
Disease and drug therapy often have an adverse effect on pregnancy outcome
maternal hyperthyroid effect on neonate
Observe neonates for s/s of thyroid dx. S/s may not appear for 5-10 days after birth.
Hyperthyroidism in neonates may resolve in 1-3 months.
if MOB has graves, baby might have graves
Neonatal grave’s: increased HR, FGR, goiter, CHF
UTI in pregnancy, effects of fetus
FGR Chronic hypoxia Sepsis CNS Damage Fetal death
connective tissue disorder in pregnancy?
Rheumatoid arthritis
Multiple sclerosis
Scleroderma
Lupus
prenatal infections?
HIV, AIDS Hepatitis Pyelonephritis Chorioamnionitis STD’s CMV
preeclampsia vs eclampsia?
PE: development of HTN & proteinuria or edema during pregnancy after the 20th week gestation in a previously normotensive, non-proteinuric woman
Eclampsia: PE with seizure activity
Incidence
5-7% of pregnant women
closer to 10-20% in our population 2* to risk factors
risk factors for preeclampsia?
Primigravidas or 1st pregnancy with current partner
Teens or older gravida
Low socioeconomic & poor nutritional status
Previous history of PE
Familial history
Multiple gestation
Medical conditions: DM, CHTN, renal, lupus
RH incompatibility
preeclampsia maternal effects?
2nd leading cause of maternal mortality Vasospasms uteroplacental insufficiency kidney damage cerebral & visual changes Pulmonary & hemodynamic changes Fluid & electrolyte shifts/imbalances Seizures HELLP (10-24% mortality) DIC
preeclampsia fetal effects?
Prematurity & related sequelae
FGR
Uteroplacental insufficiency
Effects of MgSO4
what affect FHR/maternal?
- CHTN * smoking
- DM * nutrition
- ETOH
what affects FHR/fetal?
- intact CNS
- parasympathetic = “pokey”
- sympathetic = “speedy”
- chemorecpetors
- baroreceptors
- hormones
- anomalies
- FGR
what affects FHR/placental?
placental/cord anomalies
cord compression
what is baseline for FHR?
110-160
what are the functions of AF?
environment for fetal movement
protects fetus against external injury
maintain temperature
prevents amnion from adhering to fetus
normal values of AF?
12 weeks: 50 cc
36-38 weeks: 1000 cc
after 38 weeks: slight decrease in AFI
values for polyhydramnios?
Greater than 2000 cc of fluid (AFI > 20)
Fluid pocket > 8 cm
neonatal manifestation of polyhydramnios?
Tight, shiny abdomen Abdominal discomfort Dyspnea Orthopnea Edema of abdomen, vulva, legs Uterine enlargement (size > dates) Difficulty in outlining fetal parts and FHR
values for oligohydramnios?
Severely reduced amount of amniotic fluid
AFI < 5.0 (< 500 cc of fluid)
Fluid pocket < 2 cm
polyhydramnios fetal complications?
Prolapsed umbilical cord at ROM
increased incidence of malpresentation
increased perinatal mortality
associated with fetal anomalies
neonatal implications for oligohydramnios?
Associated with renal anomalies Wrinkled, leathery skin Pulmonary hypoplasia increased skeletal deformities Fetal hypoxia Associated with postdate pregnancy 1 cm or less AFI associated with 40X in perinatal mortality
test timing for fetal well-being?
US: 6 weeks to confirm pregnancy; anatomical 16-20 weeks
Amniocentesis: 14-20 weeks, for lung maturity 35-36 weeks
Chorionic Villus Sampling (CVS) 9.5 and 12.5 weeks
Maternal blood sampling for fetal blood cells
Maternal serum alpha-fetoprotein (MSAFP): 16 and 18 weeks
Maternal serum beta-HCG: anytime
Maternal serum estriol: third trimester
placental tests
functions: providing oxygen and gas exchange; transfer of macro- and micronutrients, vitamins, hormones, and antibodies; elimination of waste products; metabolism of glycogen, cholesterol, and fatty acids; and endocrine secretion of hormones that sustain pregnancy
high AFP
NTD, anencephaly, spina bifida, omphalocele and gastroschisis; 16-18 weeks; not 100% specific, always confirm with US; elevated AFP is wrong estimation of GA; helpful with trisomies
human genome project
Launched in 1990, international effort first to map and eventually sequence all of
estimated 50,000-100,000 genes.
Human genetic map produced in 1998 – showing chromosomal locations of
markers from >30,000 human genes.
Complete human genetic sequence published in 2003.
Initiatives to establish genetic and environmental causes of common diseases
launched in 2006.
HIPPA LAW
Prevents insurance companies from denying coverage based on genetic testing.
Federal law – Genetic Information Nondiscrimination Act (GINA) in 2008 prevents US insurance companies and employers from discriminating based on information derived from genetic tests.
Insurers/employers not permitted to request or demand genetic testing.
Noonan syndrome
generalized edema, low posterior hairline occurs with a short or webbed neck, Increased nuchal translucency
nondisjunction
the MOST FREQUENT CAUSE of all chromosome d/o; Occurs when paired chromosomes fail to separate during cell division
nondisjunction before fertilization
all cells have abnormal makeup
· Ex: Trisomy, Monosomy, Polyploidy
nondisjunction after ferilization
2 or more cell lines in same cell
· Ex: Mosaicism
duplication
extra copy of a gene or DNa sequence
Inversion
part of chromosome has moved from its location
translocation nonreciprocal
a piece of chromosome that has detached and attached to another chromosome
translocation reciprocal
exchange of parts between two chromosomes
x-linked dominant characteristics of transmission
Affected MALES transmit to ALL daughters and NONE of sons
Affected FEMALES (heterozygous)transmit to HALF of their offspring (M or F)
Affected FEMALES (homozygous) transmit the trait to ALL of their children
Females are less likely to express the trait in a milder form
x-likned recessive transmission
Trait occurs almost exclusively in MALES
Trait is NEVER transmitted directly from father to son
Trait passed from affected MALE to ALL of his DAUGHTERS (Carrier)
50% of the CARRIER WOMEN’s SONS will be affected and 50% of her Daughters will
be carriers
mitochondrial transmission
Result from insufficient energy production in critical tissues
FEMALES pass on disorder (b/c mitochondria are in the egg); Risk is up to 100%
FEMALE offspring of affected female will inherit some abnormal mitochondria- but may not
manifest disease
MALES have no risk of passing on to offspring
Usually present with: visual loss, seizures, encephalopathy, progressive myopathy, diabetes
syndromes
Collection of anomalies involving more than one developmental region or organ
system; or a pattern of multiple anomalies thought to be related
· Chromosomal syndromes are the malformation syndromes usually dx in neonatal period
o Ex: T21, T18, T13, 45X, DiGeorge, Beckwith-Wiedmann
sequences
a pattern of multiple anomalies derived from a single known or presumed structural
defect or mechanical factor- followed by secondary events
o Potter, Amniotic band, Arthrogryposis, Pierre Robin
associations:
nonrandom occurrence of multiple malformations; no etiology has been identified
o VATER
homozygous vs heterozygous
Homozygous: You inherit the same version of the gene from each parent, so you have two
matching genes.
Heterozygous: You inherit a different version of a gene from each parent
Someone is homozygous for the normal gene (has two normal copies)
Someone is heterozygous (has one normal and one abnormal copy)
Someone is homozygous for the abnormal gene (has two abnormal copies)
