B8.015 Big Case: Normal Pregnancy Flashcards
first trimester length
weeks 0- 13w6d
second trimester length
weeks 14- 27w6d
third trimester length
weeks 28- 40w6d
important screening in pregnancy that can often be missed
interpersonal violence
pregnancy is when a woman is most likely to experience violence
prevalence is 4-8%
cal increase per day in pregnancy
500 cal per day
total weight gain in pregnancy
25-35 lbs
more for underweight women, less for overweight women
sometimes weight neutral if obese
vitamin intake in pregnancy
calcium- 1000 mg daily
folic acid- 400 mcg daily
vitamin D- 600 IU
iron, vit A, DHA
importance of folic acid
prevents 70% of neural tube defects
protein intake in pregnancy
half of your weight in lbs
important for tissue development
foods to limit and avoid in pregnancy
limit: -caffeine avoid: -alcohol -foods with listeria risk -rare or under-cooked meats -fish with high levels of mercury
how much caffeine
10 oz coffee
2 cans soda
listeria risk foods
hot dogs, deli meat, fermented/dry sausage
soft cheeses
rare or undercooked meats
sushi with raw fish, raw eggs, caesar dressing
what are teratogens
prenatal toxicity causing structural or functional defects in fetus
cross the placenta from maternal circulation
mechanisms of teratogens
folate antagonism neural crest cell disruption endocrine disruption oxidative stress vascular disruption specific receptor or enzyme mediated
teratogenicity of benzos
specific receptor mediated
4x increase in congenital anomalies
teratogenicity SSRI
specifically paroxetine
specific receptor mediated teratogen
methotrexate teratogenicity
exposure before 40 days is lethal to embryo
later exposure: IUGR, craniofacial anomalies, abnormal positioning of extremities, mental retardation, early miscarriage, stillbirth
teratogenicity of alkylating agents
oxidative stress
IUGR, fetal death, cleft palate, microphthalmia, limb reduction anomalies, poorly developed external genitalia
teratogenicity of warfarin
specific receptor mediated
easily crosses placenta, excreted in breast milk
spontaneous abortion, stillbirth, IUGR, CNS defect
fetal warfarin syndrome
depressed nasal bridge (saddle nose)
nasal hypoplasia
flat face, chondrodysplasia (bone abnormalities)
teratogenicity of anticonvulsants
folate antagonism, oxidative stress
phenytoin and valproic acid
risk for neural tube, cardiac, skeletal defects, and craniofacial malformations
teratogenicity of retinoids
acne treatment (accutane)
neural crest cell disruption
risk of spontaneous abortion in first trimester 50%
CNS, cardio, and craniofacial defects (esp ear)
teratogenicity of tobacco
vascular disruption
increased risk for fetal death
low birth weight
teratogenicity of alcohol
high concentrations in fetus
-fetal liver metabolizes alcohol slower
-amniotic fluid may act as reservoir
neurocognitive and behavioral problems lifelong
fetal alcohol syndrome (FAS)
prenatal/postnatal growth deficiency diagnostic facial features -short palpebral fissure length (eyes appear further apart) -smooth philtrum -thin upper lip CNS deficits
embryonic age vs gestational age
GA= first day of last menstrual period EA= 2 weeks after LMP
week 1 of fetal development
fertilization to implantation
week 2 of fetal development
implantation to formation of chorion
HCG released
pregnancy test +
week 3 of fetal development
neurogenesis, cardiogenesis begins
-these processes usually complete by 12 wks
week 4 of fetal development
neural crest differentiation
-closure of the anterior and posterior neuropore
-failure of posterior neuropore closure results in spinal bifida
heart beating
organogenesis begins
week 5 of fetal development
limb buds forming
pseudoglandular stage of lung development begins
-fluid filled primitive respiratory tree resembles exocrine gland
-too immature for gas exchange
week 10 of fetal development
random movements occurring
organogenesis complete
heartbeat heard with electronic monitor
GxPxxxx
gravida = total number of times pregnant para = births TPAL term = >37 weeks preterm = 20-36w6d abortus = spontaneous or induced miscarriage <20 wks living = living children
pregnancy confirmation labs
urine HCG (qualitative test) serum HCG (quantitative test) -doubles every 48h -peaks 8-9 wks
initial prenatal labs
hematologic -CBC -blood type and screen for alloimmunization Abs urine -urinalysis -screen for asymptomatic bactiuria infectious disease
asymptomatic bactiuria
risk factor for miscarriage or preterm birth
infectious disease prenatal testing
syphilis (RPR) HIV hep B hep C, if risk factors gonorrhea/chlamydia
concerning infectious exposures in pregnancy
zika parvovirus B19 CMV varicella zoster HSV coxsackievirus rubella
zika transmission
sexually
mosquito
zika birth defects
can cause microcephaly and other brain defects
-confirmed zika in pregnancy = 5-10% zika associated birth defects
-highest risk of birth defects with exposure in 1st trimester
avoid travel to affected areas
parvovirus B19 transmission
respiratory secretions
parvovirus B19 symptoms
children: 5ths disease, slapped cheek rash, fever, body rash, joint pain
adults: reticular rash on trunk, peripheral arthropathy, transient aplastic crisis
parvovirus B19 birth defects
spontaneous abortion, non-immune hydrops fetalis, stillbirth
CMV transmission
body fluid
ubiquitous herpesvirus; remains latent in host cells
risk of vertical transmission highest in 3rd trimester
most common congenital infection
symptoms of CMV
jaundice, grow restriction, myocarditis, non immune hydrops
**most infants asymptomatic
VZV transmission
respiratory droplets
remains dormant in sensory ganglia
symptoms of VZV
children: primary infection- fever, malaise, maculopapular pruritic rash that turns vesicular
reactivation: painful, vesicular, erythematous rash in dermatome
adults: encephalitis, pneumonia
congenital chickenpox
skin scarring
limb hypoplasia
chorioretinitis
microcephaly
HSV transmission
direct contact
how to avoid HSV in neonates
acyclovir at 36 wks to avoid outbreak
if genital outbreak, c-section delivery
neonatal HSV
limited skin/eye/mouth
encephalitis
disseminated infection: CNS, lung, liver, adrenal
coxsackievirus transmission
enterovirus - common in summer and fall
spread by respiratory droplets and fecal-oral
contraction near delivery can infect infant
coxsackie symptoms
hand, foot, mouth disease
high fever leading to miscarriage
rubella transmission
respiratory droplets
exposure worst in first 12 wks
congenital rubella syndrome
deafness**
cataracts, heart defects, intellectual disabilities, liver and spleen damage, low birth weight
MMR vaccine
do not give in pregnancy, live vaccine
vaccinate after delivery
week 12 of fetal development
external genitalia differences may be seen
week 16 of fetal development
canalicular stage of lung development begins
- resp tree expands
- angiogenesis occurs along airways
- resp bronchioles and alveolar ducts form
- cranial portion of lungs develop quicker
week 17 of fetal development
pseudoglandular stage of lung development ends
week 22 of fetal development
general cut off for viability (resuscitation attempted in this time frame)
survival outside womb = 65%
survival without major morbidity = 9%
weeks 22-24 of fetal development
terminal saccular stage of lung development begins
- alveolar cells differentiating into cells that can make surfactant (needed to sustain gas exchange)
- capillaries form complex network, lymphatic system developing
week 25 of fetal development
canalicular stage of lung development ends
first trimester genetic screen (10-14 weeks)
US for nuchal translucency
-thickness at space in back of fetus neck
HCG
PAPP-A
second trimester genetic screening (16-20 weeks)
quad screen
- msAFP
- UE3
- HCG
- inhibin A
what is cfDNA/NIPT
cell free fetal DNA
-screened for trisomy 13,18,21 and sex
-can be done as early as 10 weeks
CANNOT be done with multiple gestations
confirmation of genetic screens
amniocentesis or chorionic villus sampling
more invasive and carry risks
what is AFP
alpha fetoprotein
screens for neural tube defects
found in fetal circulation and amniotic fluid, enters maternal circulation through placenta and amniotic fluid
when should the neural tube close
week 4 of fetal development
anterior neuropore closes day 24, posterior neuropore day 26
AFP not found in maternal serum until second trimester
how neural tube defects manifest in screening
AFP leaks into amniotic fluid
if defect is covered by a membrane however, testing may miss it
where is AFP produced
yolk sac > GI tract > liver
filtration by fetal kidney > amniotic fluid
how are AFP results reported
multiples of the median
-adjusted for multiple variables: weight, race, multiple gestation, diabetes
best time to test AFP
embryonic age 14-16 weeks (GA 16-18 weeks)
- acceptable between 15-22 wks GA
- inaccurate dating common cause for false positives
reducing risk for NTD
taking folic acid (400 mcg per day)
1 month prior to conception and during the first 3 months of pregnancy
gestational diabetes prevalence
7% of pregnancies affected by diabetes
-86% of these are gestational
USPSTF recommends all pregnant women be screening
complications of gestational diabetes
preeclampsia
c-section
maternal development of DM2
when do you screen for gestational diabetes
24-28 weeks gestation
OGTT
2 step: 50 g glucose > serum glucose in 1 hr if posivite: 100 g glucose > serum glucose 1, 2, 3 hr if 2 abnormal, diagnose GDM
if diagnosed with gestational diabetes
nutrition referral
monitor blood sugar
treat if blood sugar levels high (meds or insulin)
week 26 of fetal development
survival outside the womb 94%
survival without major morbidity 59%
what is the late fetal period
week 30 of fetal development and beyond
processes that occur in the late fetal period
alveolar stage of lung development
-majority of gas exchange surface formed
maturation of surfactant system
how to treat surfactant deficits in preterm babies
surfactant and corticosteroid injections
when should you rescreen for STIs?
3rd trimester if risk factors risk factors: -prior positive test -new or multiple partners -partner w STI -inconsistent condom use -exchanging sex for money or drugs -living in areas with high prevalence
Group B strep transmission
streptococcus agalactiae
-10-30% of pregnant women colonized in vagina or rectum
lives in GI tract and can spread to GU tract (not an STI)
Group B strep infection in pregnancy
can cause ascending infection: neonatal sepsis due to GBS
vaginal and rectal culture performed 35-37 weeks
treatment of group B strep in pregnancy
routine intrapartum antibiotics (penicillin) given in labor
-80% reduction in neonatal sepsis due to GBS
effects of cocaine/meth on pregnancy
vascular disruption
-preterm birth, placental abruption, fetal distress, IUGR
irritability, hyperactivity, tremors, high pitched cry
effects of marijuana on pregnancy
no withdrawal signs
not sure of long term outcomes
effects of SSRIs on pregnancy
irritability, restlessness, tremor, respiratory distress
-consistent with gradual resolution of hyperserotonergic state
onset hours to days after birth, resolves in 1-2 weeks
no adverse neurodevelopmental outcomes
worst/best SSRIs for pregnant women
paroxetine = worst
fluoxetine and sertraline = best
neonatal abstinence syndrome
opioid withdrawal
irritability, autonomic over reactivity, GI dysfunction
excess environmental stimuli/ hunger exacerbates
treated with morphine
why are preterm infants at lower risk of opiate withdrawal
less length of exposure
lower fat stores
immaturity of CNS
important time points of fetal development
all in EA
week 3: neurogenesis, cardiogenesis begin
week 4: neural crest differentiation, organogenesis
week 5-17: pseudoglandular stage of lung development
week 10: organogenesis complete
week 16-25: canalicular stage of lung development
week 22-late: terminal saccular stage of lung development
week 30: alveolar stage of lung development, maturation of surfactant system
things 2 do in the first trimester
- confirm pregnancy (HCG)
- initial prenatal labs: CBC, type and screen, HIV, RPR, hep B, rubella, G/C, UA, urine culture
- 10 w GA - NIPT
- 10-14 w GA - 1st trimester genetic screen
things 2 do in second trimester
16-20 w GA - quad screen
16-18 w GA - msAFP
24-28 w GA - GDM (gestational diabetes)
things 2 do in third trimester
STI rescreen
-HIV, RPR, gonorrhea
35-37 w GA - GBS
