Maternity Ch. 3 Flashcards
Teratogens
drugs, viruses, infections, or other exposures that have the potential to cause embryonic/fetal developmental abnormality
***Environmental toxins (ex: where they work like use of chemicals)
How is the degree of malformations from teratogens based on?
Based on length of exposure, amount of exposure, and when it occurs during human development
Effects of tegretol (cabamazepine)
Increased risk of:
Neural tube defects
Craniofacial defects, including cleft lip and palate
Intrauterine growth restriction
Effects of toxoplasmosis
Increased risk of:
Fetal demise
Blindness
Mental retardation
Where can you contract toxoplamosis?
Due to cats ( don’t change cat litter)
Undercooked beef/lamb
Embryo
Developing human from time of implantation through 8 weeks of gestation
Organogenesis
Formation and development of body organs
-happens at 8 weeks
Primary germ layers ?
What do they do?
Ectoderm, Mesoderm, and endoderm
Form the organs, tissues, and body structures of the developing human
When does the heart form?
3rd week of gestation and begins to beat and circulate blood during the 4th week
Fetus
week 9 to birth
How is the placenta formed?
from both fetal and maternal tissue
FXNs of placenta
- Metabolic and gas exchange
- Hormone production
Placenta: Metabolic gas exchnage
In the placenta, fetal waste products and CO2 are transferred from the fetal blood into the maternal blood sinuses by diffusion. Nutrients such as glucose and amino acids and O2 are transferred from the maternal blood sinuses to the fetal blood through the mechanisms of diffuse and active transport.
***Does not create nutrients but allows for exchange
Hormones produced in the placenta
- Progesterone
- Estrogen
- hCG
- hPL
Progesterone fxn
Progesterone facilitates implantation and decreases uterine contractility
Estrogen fxn
Estrogen stimulates the enlargement of the breasts and uterus
hCG
hCG stimulates the corpus luteum so that it will continue to secrete estrogen and progesterone until the placenta is mature enough to do so. This is the hormone assessed in pregnancy tests. hCG rises rapidly during the first trimester and then rapidly declines.
hPL
hPL promotes fetal growth by regulating available glucose and stimulates breast development in preparation for lactation
What can cross placental membrane?
Viruses such as rubella and cytomegalovirus can cross the placental membrane and enter the fetal system, potentially causing fetal death or defects. Drugs can also cross the placental membrane.
Category of drugs mom should avoid?
C, D, and X
Embryonic sac fxn
“bag of waters”
help maintain a sterile environment by forming a barrier that prevents bacteria from entering the amniotic fluid through the vagina
What happens if water breaks?
Mom is committed to labor
What color do we want amniotic fluid?
Clear
Where is amniotic fluid made in first, second, and third trimesters?
During the first trimester, the amniotic membrane produces amniotic fluid; during the second and third trimesters, it is produced by the fetal kidneys.
Amniotic fluid fxn
● Cushions the fetus from sudden maternal movements.
● Prevents the developing human from adhering to the amniotic membranes.
● Allows freedom of fetal movement, which aids in symmetrical musculoskeletal development.
● Provides a consistent thermal environment.
Umbilical cord connects
the fetus to the placenta
AVA
Nutrition and gas exchange
***If only two vessels = big issues
