Topic 2 Fetal Development Flashcards
Why is BPA or Bisphenol A bad?
It is related to male reproductive disorders and prenatal exposure is associated with increased methylation levels in girls. It mimics hormones like estradiol which interferes with development in males and females.
Overall affects health via infertility, cancers, and neurological issues in kids.
What are two main viral agents that can affect pregnancies?
Herpes (HSV) and Zika
HSV-1 is usually associated with oral lesions and HSV-2 with genital lesions. How has this changed? What are the implications?
HSV-1 in some population is responsible for about 40% of genital herpes infections.
You now have to figure out if you have HSV-1 or -2
How is HSV-1 passed onto a baby?
Through the birth canal while mother is passively or actively infected in genital area.
First (mild) major category of postnatal HSV infection?
The HSV disease is localized to skin, eye, and/or mouth with low mortality and could lead to encephalitis (moderate) or disseminated disease (severe) if untreated.
Second (moderate) major category of postnatal HSV infection?
HSV encephalitis with or w/o skin, eye, and/or mouth involvement which causes neurologic morbidity among survivors.
Third (severe) major category of postnatal HSV infection?
Disseminated (whole body) HSV which manifests as severe multiorgan dysfunction with 80% mortality risk w/o therapy.
What is the difference in having had the HSV disease and just newly acquiring it during pregnancy?
Newly acquired HSV makes for a high risk of transmission to the baby.
If you’ve had it before there’s less of a chance.
Zika virus is what and leads to what?
It’s a single-stranded RNA virus that leads to microcephaly, intrauterine growth restriction, ocular abnormalities, and fetal death.
Not seen much in US.
What are the two common antibodies?
IgM and IgG
What is IgM and its characteristics?
Fast and fairly immediate antibodies that fight off viruses. Initiates in telling the body to make IgG antibodies. Made up of 5 antibodies (pentagonal shape).
What is IgG and its characteristics?
IgG antibodies are longer-term helpers that spike during infection and wait a while after to respond again faster.
Main antibody and is the only isotype that can pass through placenta.
Can viruses like covid pass the placental barrier?
Yes, but RARELY. Especially covid in comparison to other viruses.
Some peeps were reported to have passed on COVID-19 antibodies to their children to help fight it off in the future.
How does timing affect IgG production and pass-on to the baby?
The longer the mom has the virus, the more IgG she will pass on to her baby.
How does covid actually hurt the mother and child?
It attacks the placenta itself rather than cross and get to the baby directly.
What is the prime example of a drug teratogen that was prevented by Francis Kelsi?
Thalidomide which resulted in malformed babies with flippers (phocomelia)
What is thalidomide used for now?
Leprosy disease treatment and multiple myeloma.
Why does alcohol affect fetuses so much?
Alcohol breaks down a lot more slowly in a fetus, so it retains it in their body.
Leads to FAS, or fetal alcohol syndrome.
How is birth mediated by positive feedback?
By using estrogen and oxytocin.
Baby pushes against he cervix, causing it stretch.
Stretching of cervix sends impulse to brain.
Brain STIMULATES POSTERIOR PITUITARY to RELEASE OXYTOCIN.
OXYTOCIN causes smooth muscle lining in uterus to contract.
Continues until more stretching and contractions lead to birth of fetus into baby.
What is estrogen in relation to pregnancy?
A steroid that comes from the ovaries and induces oxytocin receptors on uterus.
Umbrella term as well, and estriol is main worker in contractions.
What is progesterone?
A hormone that helped prevent uterine contractions because it initially helps with implantation and maintenance of baby.
Gets inhibited by estriol because then it needs to be gone for contractions to start.
What is oxytocin?
Helps with birthing process by reinforcing contraction via positive feedback in tandem with estriol.
What is prostaglandins?
Hormones secreted by placenta to stimulate more contractions which makes more oxytocin to produce more contractions.
Difference between estriol and estradiols?
Estriol is just one more hydroxide (-OH) group (it’s in the name, es-tri (3) - ol). Estra-di-ol is just 2 total and one less hydroxide group.
Estriol is produced in liver and placenta and is 8% as potent as estradiol. Measurable during pregnancy. Is anti-cancer and a metabolite (byproduct/waste) of estradiol.
Estradiol is produced in the ovaries and adrenal gland and is the major form of estrogen produced in ovaries. Most potent form of estrogen. Levels fluctuate throughout phases of the menstrual cycle.
