definitions
embryonic development
Fetal
period1
period1
Fetal
period2
period2
Fetal
period3
period3
Teratology
100
What is the difference between GA and Ovulation age
Gestational age or menstrual age is the time elapsed since the first day of the last menstrual period (LMP)2 weeks before ovulation( 40 weeks)
ovulation age, or the time in days or weeks from ovulation. Another term is postconceptional age. ( 38weeks)
100
How many days after fertilization does blastocyst implant
6-7 days
100
After 13 weeks how is fetal growth measured
biparietal diameter, head circumference, abdominal circumference, and femur length are measured
100
when is the ideal timing for folic acid supplementation
the cranial end of the neural tube closes by 38 days from the last menstrual period, and the caudal end closes by 40 days. Hence, folic acid supplementation to prevent neural-tube defects must be in place before this point.
100
what is the hct cut off that is considered fetal anemia
30
100
what percentage of birth defect is cause by medications
according to FDA <1%
80% do not have obvious etiology,
of those with identified causes 95% hace chromosomal or genetic origins
200
How do you calculate EDC based on Naegele rule
e.g LMP 10/10/2025
substracte 3 months and add 7 days
LMP 10/10-->(10/10) - ( 3 months) = ( 7/10) + 7 days = 7/17/2026
200
how long is the embryogenic period
Begins third week from LMP and continue through the eighth week.( 6 weeks)
200
between which GA does Midbrain maturation, eye movement, Uterus formation and vaginal canalization ( in female) and testicular descent in male occurs
16-20 weeks
200
Which famous gene partially control development of the brain
HOX genes.
200
Measurement of which type of immunoglobulin may indicate congenital infection
IgM
Bulk of IgG is acquired during last 4 weeks from maternal. IgM does not cross the placenta so any IgM measured in umbilical cord is that of fetus
elevated IgM levels are usually found in newborns with congenital infection such as rubella, cytomegalovirus infection, or toxoplasmosis
200
name at least 2 reliable sources for accurate and updated risk information of substance/medications
pubMed, Reprotox, TERIS, Shepard’s Online Catalog of Teratogenic Agents, Lactmed, to name a few !
300
What is the embryogenic period, how long does it last
time during which organogenesis take place.
300
When do somites appears
A= presomites (19days ovulation age) , B= 7 somite @ 21 days, C= 17 somite @22 days
300
GA at which secretory type II pneumocytes initiate surfactant secretion
survival rate at GA ?
24 weeks :The canalicular period of lung development, during which the bronchi and bronchioles enlarge and alveolar ducts develop, is nearly completed.
~50% :will die because the terminal sacs, required for gas exchange, have not yet formed.
300
Which 2 organs receive the most oxygenated blood
Brain and heart , Shunt from RA to RV through foramen ovale
300
After 10 week of GA, what is the percent cfDNA in maternal plasma that representes trophoblastic DNA
10-15 %
This phenomenon underlies one maternal-serum screening method for fetal aneuploidy,
300
what is the leading cause of preventable developmental disabilities worldwide
Alcohol ! No amount of alcohol is safe in pregnancy
Fetal alcohol syndrome
400
what is the fetal period
After most organs system have developed, period of growth and maturation, 7 weeks after ovulation ( 9 weeks after lmp)
400
when does the cranial and caudal end of the neural tube closed
( Days from LMP)
38= cranial, 40 = caudal. neural tube has closed by end of 6 week
400
What is the major site of hematopoiesis after 28 weeks
bone marrow
Prior to that, it is the liver and spleen mainly .
400
what is the predominant hemoglobin type in fetal life
Hgb F is the main type (3/4 of hgb at term , declines within 6-12month after birth)
initially Alpha (α) and zeta (ζ) globin chains are interchangeable(until 6 weeks of GA). The beta (β) globin chain can be replaced by epsilon (ε), gamma (γ), or delta (δ) globin chains. In embryonic life (stage I), ζ and ε globin chain production is gradually replaced by α and γ globin chain production. Hgb F is the main type
400
name one the protein that aid in placental sequestration oh Heavy metals
metallothionein-1 is expressed in human syncytiotrophoblast. This protein binds and sequesters a host of heavy metals, including zinc, copper, lead, and cadmium.
400
how long after methotrexate use should pregnancy be delayed?
Expert opinion recommend 1-3 months after discontinuation as methotrexate may persist up to 4 months in the liver
500
Teratogen vs fetotoxin
Teratogen :agent that acts during embryonic or fetal development to produce a permanent alteration of form or function. causes structural abnormalities
Fetotoxins: affect development in the fetal period or postnatally
500
Estimate the GA difference between ( A and E) 
6 DAYS between 8 somite and 33
Three- to four-week-old embryos. A, B. Dorsal views of embryos during 22 to 23 days of development showing 8 and 12 somites, respectively. C–E. Lateral views of embryos during 24 to 28 days, showing 16, 27, and 33 somites, respectively.
C=A, D=B
500
earliest GA at which 90 % of fetuses have a chance of survival without physical or neurological impairment
28 weeks
500
Name the 5 secondary brain vesicle that develop by week 7
During the sixth week, the cranial end of the neural tube forms three primary vesicles. In the seventh week, five secondary vesicles develop
500
4 stages of lung maturity
pseudo glandular stage : 5-17week
Canalicular stage : 16-25
terminal sac stage : after 25 weeks
Alveolar stage : late fetal period until well into childhood
500
Leflunomide used to treat Rheumatoid arthritis and psoriatic arthritis remains detectable for as long as 2 years after discontinuation.
Pregnancy should be avoided until serul drug level fall below what level ... and on how many occasion
below 0.02mg/dl, on two occasions 2 weeks apart