Histology - Fetal Development and Complications - Reverse Flashcards by N Eberhart

Measures of body length (CRL, lemur length) increase faster than measures of width increase (biparietal diameter, abdominal circumference).

Fetal Proportional Growth

How well did you know this?

Not at all

Perfectly

3200 g (7 lbs)

Normal Birth Weight

How well did you know this?

Not at all

Perfectly

< 2500 g (5.5 lbs)

Low Birth Weight

How well did you know this?

Not at all

Perfectly

< 500 g (1.1 lbs)

Fatal Birth Weight

How well did you know this?

Not at all

Perfectly

< 10th percentile in weight for gestational age, but weight for size is normal

Small for gestational age (SGA)

How well did you know this?

Not at all

Perfectly

< 10th percentile in weight for gestational age and < 2.5th percentile for abdominal circumference. Mortality is 30 times more likely, mental development may be affected.

in utero growth retardation (IUGR)

How well did you know this?

Not at all

Perfectly

Preterm birth

How well did you know this?

Not at all

Perfectly

test for preterm delivery risk: vaginal swab for placental adhesive glycoproteins

Fetal fibronectin (fFN) test

How well did you know this?

Not at all

Perfectly

Respiratory distress due to underdeveloped lungs

Respiratory distress syndrome (RDS)

How well did you know this?

Not at all

Perfectly

glucocorticoids to promote surfactant secretion in the lung to prevent collapse.

Respiratory distress syndrome (RDS) prenatal treatment

How well did you know this?

Not at all

Perfectly

continuous positive airway pressure (CPAP) to maintain airway patency.

Respiratory distress syndrome (RDS) POST-natal treatment

How well did you know this?

Not at all

Perfectly

test for RDS risk. Lecithin should rise relative to sphingomyelin beginning in the 34th week, 2:1 = low RDS risk. Amniotic fluid sampled by amniocentesis or vaginal swab.

Lecithin-sphingomyelin ratio

How well did you know this?

Not at all

Perfectly

sampling amniotic fluid w/ needle guided by ultrasonography. 14-20 weeks for adequate fluid. Fetal calls for karyotyping, fetal metabolites, proteins, hormones, etc.

Amniocentesis

How well did you know this?

Not at all

Perfectly

biopsy of chorionic villus w/ needle guided by ultrasonography. 10-14 weeks (after 14 wks, amniocentesis preferred). Slightly higher risk (1-2%), less accurate, earlier karyotyping.

Chorionic villus sampling (CVS)

How well did you know this?

Not at all

Perfectly

identifying fetal markers in maternal blood. Looking for a-fetoprotein and hCG levels. False positives numerous.

Maternal serum screening

How well did you know this?

Not at all

Perfectly

fetal marker in maternal blood that can show neural tube defects, GI defects, Down syndrome

a-fetoprotein

How well did you know this?

Not at all

Perfectly

fetal marker in maternal blood used to test for molar pregnancy, ectopic pregnancy, choriocarcinoma, down syndrome.

hCG

How well did you know this?

Not at all

Perfectly

Encoscopic procedure to visualize the fetus. Invasive, high risk (5-10%), used only in extreme casus

Fetoscopy (fetendo)

How well did you know this?

Not at all

Perfectly

sampling of umbilical vein blood for genetic or metabolic disoreders (also called cordocentesis). > 17 weeks (cord large enough), same risk as CVS (1-2%)

Percutaneous Umbilical Cord Blood Sampling (PUBS)

How well did you know this?

Not at all

Perfectly

extraction of fluid from the peritoneal cavity within the abdomen. Invasive: must penetrate vagina and peritoneum. Looking for blood; indivative of tubal rupture during ectopic pregnancy.

Culdocentesis

How well did you know this?

Not at all

Perfectly

dilation of the cervix and removal of endometrium (scraping or suction). Screens for polyps, cancer, ectopic pregnancy. Placental tissue floats in saline, cancer doesn’t. comparison with hCG levels usually necessary.

Dilation and curettage (D and C)

How well did you know this?

Not at all

Perfectly

waxy or cheese-like white substance found coating the skin of newborn human babies. Starts developing on the baby in the womb around 18 weeks into pregnancy.

Vernix caseosa

How well did you know this?

Not at all

Perfectly

very fine, soft, and usually unpigmented, downy hair as can be found on the body of a fetusor newborn baby. It is the first hair to be produced by the fetal hair follicles, and it usually appears on the fetus at about 5 months of gestation.

Lanugo

How well did you know this?

Not at all

Perfectly

Formed by fusion of amnion and chrion. Ruptures prior to birth, ‘water breaking’.

Amniochorionic membrane (ACM)

How well did you know this?

Not at all

Perfectly

Premature rupturing of the ACM. Bands/cords of ACM constrict fetal body parts, may affect development of more distal structures.

Amniotic Band Sundrome (ABS)

500-1000 ml of circulating clear, watery liquid that contains fetal cells, proteins, electrolytes that can be collected via aminocentesis.

Amniotic fluid

amniotic cells lining cavity, fiddusion of maternal tissue fluid, fetal urination.

Sources of Amniotic fluid

Enters fetal circulation by being swallowed into GI tract, aspiated into lungs, and absorbed through skin. Returns to maternal circulation through uteroplacental circulation, excretion into amniotic cavity and diffusion into maternal tissue.

Amniotic fluid circulation

Cushions, prevents adhesion, permits movement, permits growth, barrier to infections, regulated body temperature, regulates fluid/electrolyte homeostasis.

Amniotic fluid functions

too much amniotic fluid; >1500 ml. Assoc. w/ severe malformations that prevent swallowing of amniotic fluid.

Polyhdramnios

Too little amniotic fluid; < 400 ml. Assoc. w/ renal agenesis, urinary blockages, premature rupture of ACM (PROM). May lead to slowed growth or oligohydramins sequence.

Oligohydramnios

Abnormal appearance due to compression of fetus against uterus, e.g., limb abnormalities, flattened face. Typically caused by bilateral renal agenesis or ACM rupture. Characterized by oligohydramnios, anuria (no urination), pulmonary hypoplasia (under-developed lungs)

Oligohydramnios (Potter’s) Sequence

Attaches fetus to placenta. (55 cm length, 1-2 cm diameter) Contains: 1 umbilical vein (blood: placenta to fetus), 2 umbilical arteries, (blood: fetus to placenta), loops of intestine, yolk sac, vitelline vessels, allantois (waste collection).

Umbilical cord

risk of cord prolapse or the cord encircling fetal neck, called nuchal cord.

long cord

restricted fetal movements, early detachment of placenta from uterus during delivery.

short cord

fetal hypoxia/anoxia (little/no oxygen); may be fatal

True knot (umbilical)

Collection, storage of fetal blood cells. Alternative to bone marrow transplants. Pros: No discomfort, abundant viabble stem cells, minimized host-graft rejection. Cons: expensive, low prob of use.

Umbilical cord blood banking

site of nutrient and gas exchange between fetus & mother; produces pregnancy hormones like hCG.

Placenta

maternal part of the placenta, derived from endometrium

Decidua basalis

fetal part of placenta, derived from chorion

Villous chorion

endometrium during pregnancy adjacent to the smooth chorion

decidua capsularis

endometrium during pregnancy not directly associated with the chorion.

decidua parietalis

name for extraembryonic mesoderm plus trophoblast layers

Chorion

fetal placenta adjacent to decidua basalis, highly vascular. develops as the cytotrophoblast and extraembryonic mesoderm and grows into the syncytiotrophoblast. NO MIXING OF MATERNAL AND FETAL BLOOD!!

Villous chorion

less vascular, non-placental region adjacent to decidua capsularis

Smooth chorion

1. synctiotrophoblast 2. cytotrophoblast 3. extraembryonic mesoderm 4. endothelial cells lining fetal capillaries.

Placental barrier before 4 months fertilization age

1. syncytiotrophoblast 2. endothelial cells lining fetal capillaries. Now increased exchange. Cytotrophoblast cells detach and migrate to lin maternal arteries.

Placental barrier after 4 months fertilization age

blocks: large, complex molecules, many protein hormones, many bacteria. Allows: gas, nutrient, waste exchange, steroid hormones, some antibodies, most medications/drugs, many viruses.

Placental barrier (membrane)

clinical concern > 4 months. Caused by failed migration of cytotrophoblast cells or maternal immune response to invading cytotrophoblast cells. Increases pressure in maternal vessels. Results in maternal hypertension, preoteinuria, slowed fetal growth, potential death.

Preeclampsia

follows preeclampsia and is characterized by seizures.

Eclampsia

placenta attaches to the myometrium of uterus

Placenta accreta

placenta invades myometrium of uterus

Placenta increta

placenta penetrate the uterus and extends into body cavity

Placenta percreta

dichorionic, diamniotic (DCDA, DiDi): 2 amnions, 2 chorions, 2 placentas. 2 oocytes released at ovulation & fertilized separately, unique DNA, 'fraternal'.

DZ twins

2 amnions, 1 chorion, 1 placenta. 1 oocyte released at ovulation, fertilized by 1 sperm, same DNA, 'identical'. each blastocyst implants separately in endometrium

MZ twins: dichorionic, diamniotic (DCDA, DiDi)

1 amnion, 1 chorion, 1 placenta. 1 oocyte released at ovulation, fertilized by 1 sperm. I embryblast at implantation = 1 amnion. 2 epiblasts after implantation = 2 fetuses. 1 trophoblast = 1 chorion, 1 placenta.

MZ twins: monochorionic, monoamniotic (MCMA, MoMo)

Spermreach oocyte, pass through CR. Acrosome reaction (male), Zona reaction (female). Sperm fuses with ocyte membrane, oocyte completes M2. Pronuclei fuse to from single diploid nucleus.

Day 1

Cleavage, compaction (day 4), cavitation, hatching, implantation (day 6)

Week 1

uteroplacental circulation, trophoblast differentiation (cytotrophoblast and syncytiotrophoblast.), bilaminar disc formation, chorionic cavity formation, hcG detectable day 8.

Week 2

ectopic pregnancy, placenta previa, molar pregnancy, choriocarcinoma.

Week 2 complications

Gastrulation, neurulation, NODAL expression, FGF8 expression, hypoblast displaced, body axes established, lateral body folding.

Weeks 3-4

forms urogenital system

Intermediate mesoderm

forms connective tissue of body wall and limbs

parietal layer of lateral plate mesoderm

GI/respiratory organs exxcept epithelial lining

visceral layer of lateral plate mesoderm

somites differentiate (wk 4), myotome differentiation (wk 5), resegmentation (wk 5), organogenesis

Weeks 4-8

chondrification centers for vertebral column develop

week 6

primary ossification centers for vertebral column develop

week 7

ribs form (sclerotome), tail regresses, limbs rotate/enlongate, digits and face develop,

week 8

produces floating ribs

hox9

prevents rib formation

hox 10

from parietal layer of lateral plate mesoderm

sternum formation

sacralization of vertebrae

Hox11

rostral neuropore doesn't close

Anencephaly

causal neuropore doesn't close

spina bifida

malformed pelvis, underdeveloped lower limbs, 250X more in pregestational diabetics

Caudal dysgenesis

form of CD, mermaid syndrome

Sirenomelia

Loss of function: ribcages with all ribs attacted to sternum

Mutation of Hox9

Loss of function: lumbar and sacral vertebrae with ribs. Gain of function: Thoracic vertebrae without ribs

Mutation of Hox10

LoF: Sacral vertevrae that donot fuse. GoF: vertebrae at various levels fusing

Mutation of Hox 11

fracture of pars interarticularis

Spondylolysis

Hox11 gain of function mutation at L5

Sacralization of L5 vertebra

bone ossification centers (wk 12), ext genetalia visible (wk 12), swallowing and urine formation (wk 10), respiratory movements (wk 15)

Weeks 9+ (fetal period)

weeks 24 - 28

Sound and light recognition