11/30 Fetal Growth Flashcards
When is the fetal period?
Weeks 9-38 (birth)
What happens in the fetal period
Differentiation and growth of tissues/organs, rate of body growth increases
When is the time of greatest vulnerability to death?
Weeks 1-2
When is the time of greatest vulnerability to congenital anomalies?
Weeks 3-8
What is a teratogen?
any agent that causes an abnormality after exposure during development
What can teratogens increase the risk for?
Miscarriage, preterm labor, stillbirth
What does the danger of a teratogen depend on?
teratogen, timing (when and how long), quantity, genotype
What is another name for a teratogen?
Reproductive toxicant
What does the term reproductive toxicant emphasize?
That timing and dose matter
What are the outcomes (congenital anomalies) of common medications with known reproductive toxicants?
CHDs, cleft palate, spina bifida
What are the actions of caffeine
Stimulant and diuretic
What side effects can caffeine have?
Vasoconstriction = Increases HR, BP
Increases urination and metabolism = dehydration, diarrhea
Stimulates CNS = jittery feelings, anxiety, irritability, insomnia
Does caffeine cross placenta/into breast milk?
Caffeine does cross placenta and is transferred via breastmilk
What are the current recommendations for pregnancy and those TTC for caffeine?
pregnant people: <200 mg caffeine/day (less is better)
TTC: both partners should abstain or decrease caffeine intake
What was thalidomide initially created for?
As a sedative
What was thalidomide found to be useful for?
Anti-emetic (helped morning sickness)
What can thalidomide cause?
Unusually high numbers of congenital anomalies - thalidomide embryopathy
Severe limb, eye, urinary tract, and heart defects
What is thalidomide embryopathy, what property causes this?
Severe limb defects: amelia, meromelia, phocomelia
Due to anti-angiogenic properties of thalidomide
What is the difference when thalidomide is introduced on day 24 versus 28?
Day 24 = upper limb damage
Day 28 = lower limb damage
What is thalidomide used for today?
immunomodulatory, anti-inflammatory, and anti-angiogenic causes
used to treat multiple myeloma, Hansen’s disease (aka, leprosy), certain conditions caused by cancer or HIV infection
What happens to development after weeks 17-20 in the fetal period
Growth slows quite a bit
What is quickening, when is it more common?
The first fetal movements felt by pregnant woman
Often stronger and/or more noticeable in evening or night
What is lanugo?
Fine, soft hair covering body and limbs of neonate
When does lanugo disappear and what replaces?
Disappears soon after birth and is replaced by vellus hair
What is lanugo often found in?
Teratomas
What is vernix caseosa, what does it do?
Waxy substance covering skin of neonate
Functions to keep skin moisturized, retain heat, protect, lubricate
What is used to estimate the size of fetal growth
Crown-to-rump length
What is used to estimate age of fetal growth?
Biparietal diameter, head/abdominal circumference, femur length
What is not a reliable measurement for estimation of age?
Neonatal weight
When does gestational diabetes affect pregancy? How is this detected?
Typically affects late pregnancy
Often detected during OGTT (oral glucose tolerance test)
Can insulin cross the placenta?
No
What is the mechanism of gestational diabetes?
Placental hormones block action of maternal insulin
High blood glucose passes from mother to fetus
Fetal pancreas works overtime making insulin
Extra energy in fetus is stored as fat
What are possible results for gestational diabetes in the fetus?
macrosomia, hypoglycemia, breathing problems,
increased risk of childhood obesity, increased risk of type 2 diabetes
What are possible results for gestational diabetes in the carrier/mother?
difficult birth, hypertension, preeclampsia, increased risk of type 2 diabetes (~25% higher than non-GD population)
What is the purpose of sonography/ultrasonography?
Uses sound waves to visualize tissues based on information about density
When can sonography/ultrasonography be performed?
Anytime
What is the procedure for Sonography/Ultrasonography?
Transvaginal or Abdominal
2D, 3D, 4D
Fetal echocardiography
What is the risk level for Sonography/Ultrasonography?
Little to none
When is the anatomy scan performed?
Around weeks 18-22
Does the sonographer discuss anatomy scan with patient?
Sonographer may discuss with patient throughout, but obstetrician/perinatologist reviews and follows up
What is the purpose of the anatomy scan?
Check development of fetal organs (including sex of fetus), placenta and fetal membranes, amniotic fluid, pelvic tissues
Screen for structural issues (can indicate further testing for congenital anomalies or syndromes)
What is the purpose of amniocentesis?
Collect sample of amniotic fluid to analyze fetal genotype, amount of alpha fetoprotein, respiratory secretions
When is amniocentesis performed?
> 15 weeks
What is the risk level for amniocentesis?
Moderate
Postprocedural rate of fetal loss = 1.4%
What information can alpha fetoprotein provide?
If too high = possible body wall defects or NTDs
If too low = possible syndromes
What information can respiratory secretions provide?
Status of lung maturity (surfactant production)
If maternal Rh- blood mixes with fetal Rh+ blood, what is a possible consequence?
If the first meeting, possibly no issue for current pregnancy
If second (or more) meeting, then potential Rh incompatibility sequelae
What is the purpose of Chorionic villus sampling (CVS)?
Collect sample of chorionic villus to analyze fetal genotype
When is Chorionic villus sampling (CVS) performed?
> 10 weeks (earlier than amniocentesis)
What is the risk level for Chorionic villus sampling (CVS)?
High
Postprocedural rate of fetal loss = 1.9%
What is the purpose of cordocentesis (Percutaneous umbilical cord blood sampling (PUBS))? Why is this performed?
Collect sample of fetal blood to analyze fetal genotype
• Only if amniocentesis/CVS are inconclusive or inadequate
When is cordocentesis (Percutaneous umbilical cord blood sampling (PUBS)) performed?
> 17 weeks
What is the risk level of cordocentesis (Percutaneous umbilical cord blood sampling (PUBS))?
Very high
Postprocedural rate of fetal loss = 1-4%
Is Rh incompatibility a potential issue with Cordocentesis (Percutaneous umbilical cord blood sampling (PUBS))?
Yes
What is fetal viability?
50/50 potential ability of fetus to survive in extrauterine environment with modern medical care
What is the gestational age and embryological age for fetal viability?
Gestational: ~24 weeks
Embryological: ~22 weeks
What is lung development like in week 22?
Canalicular stage, there are a few young alveoli and surfactant production just began ~week 20
What is abortion?
premature stoppage of development and expulsion of conceptus/embryo/fetus before it is viable
What is a threatened abortion?
bleeding with the possibility of abortion
What is spontaneous abortion?
Aka miscarriage
pregnancy loss that occurs naturally before week 20
When is spontaneous abortion considered habitual?
If it occurs > 3 times
What is fetal demise?
Spontaneous abortion after week 20
What is (medically) induced abortion?
birth that is medically induced before fetal viability is reached
How many clinically recognized pregnancies end in miscarriage?
1/4
How many babies in the US are born with congenital anomalies?
1/33
What can congenital anomalies necessitate?
surgeries and therapies, lifelong monitoring, specialist care, and may result in developmental delays and chronic disability
