Fetal Growth Disorders Flashcards
BW <10th percentile for GA
SGA
BW 10th-90th percentile
AGA
BW >90th percentile for GA
LGA
BW 1500-2500 g
Low birth weight
BW 1000-1500 g
VLBW
BW 500-1000 g
Extremely low birth weight
Threshold variability
Births before 26 weeks AOG
22-25
Late preterm (34 - 36 6/7 weeks) morbidities
Respiratory distress Intubation IVH Sepsis Phototherapy NEC APGAR = 3 at 5 min
Major causes of spontaneous preterm labor
Uterine distention - multifetal births, hydramnios/polyhydramnios
Premature cervical changes - cervical insuffiency
Maternal-fetal stress
Infection
Important risk factor for preterm birth in multifetal pregnancies
Premature cervical changes
Useful biomarker for preterm birth risk assessment
More accurate predictor of preterm birth if rate of increase is measured
Inc in CRH and ACTH stimulate fetal adrenal dehydroepiandrosterone sulfate -> inc estrogen (estriol) -> loss of uterine quiesence
CRH
Microbiome during pregnancy with increased dominance of Lactobacillus
Identifies microbial pooulation associated with subclinical infection induced preterm birth
Metagenomics
Ascending microorganisms invade membranes and amniotic sac leading to release of cytokines and IL
1
6
8
TNF a
Four stages of intrauterine infection
I - bacterial vaginosis
II - decidual infection
III - amniotic infection
IV - fetal systemic infection
Microbes associated with preterm birth
Gardnerella vaginalis
Fusobacterium
Mycoplasma hominis
Ureaplasmaurealyticum
More capable of burrowing through exposed tissues after cervicsl dilatation
Fusobacteria
PPROM Risk factors:
Low socioeconomic BMI = 19.8 Nutritional deficiencies Cigarette smoking Prior PPROM
Normal H2O2 producing lactobacillus replaced by
Gardnerella
Mobinculus
Mycoplasma
Bacterial vaginosis
Gold standard for diagnosing bacterial vaginosis
Based on a gram-staining study of the cervical discharge
Nuget scoring
Count the morphotype
Intracellular adhesion during implantation and in maintenance of placenta adherence to uterine decidua
Detected in cervico-vaginal secretions
Possible marker for impending preterm labor (>50 ng/ml is positive)
fFN screening is not recommended
fetal glue/pregnancy glue
Fetal fibronectin
Single course corticosteroid use is recommended in management of preterm ruptured membrane of week
24 to 31 completed weeks
42 completed weeks or 294 weeks
Post term pregnancy
Major causes of death in post term pregnancy
GHTN
Prolonged labor with CPD
Unexplained anoxia
Malformations
Lower intelligence quotient IQ
in >/= 42 weeks gestation
Post maturity Syndrome
Wrinkled, patchy, peeling skin
Long, thin body suggesting wasting
Open-eyed, unusually alert, appears old and worried
Skin wrinkling - palms and soles due to loss of protective effects of vernix caseosa
Long fingernails
Substantially increases the likelihood of postmaturity
Oligohydramnios
Cord compression associated with oligohydramnios
Intrapartum fetal distress
Amniotic fluid volume decrease after 38 weeks + meconium release = thick viscous meconium
Meconium aspiration syndrome
Velocity of fetal weight gain peaks at
37 weeks
Fetal growth phases
Phase of hyperplasia (first 16 weeks) : rapid increas in cell number
Phase of cellular hyperplasia and hypertrophy (32 weeks)
Phase of cellular hypertrophy (after 32 weeks) : most fetal fat and glycogen accumulated
Usually due to early insult causing relative decrease in cell number and size - viral infection, cellular maldevelopment, aneuploidy
Symmetrical proportionally small
More common
Usually caused by insult in the late pregnancy (third tri)
Placental insufficiency
Diminished glucose transfer
Sacrifice of blood flow to other improtant structures such as liver (decrease in abdominal circumference) and kidney which leads to decreased urine production causing oligohydramnios
Asymmetrical disproportionately lagging abdominal growth
Fetal growth restriction can lead to hypertension, atherosclerosis, DM Type 2, metabolic derangement
Barker’s Hypothesis
Triple screen in Down
Unconjugated estriol
AFP
HCG
