Exam 1 Clinical Correlations Flashcards
When is the greatest risk for spontaneous abortions?
Pre-embryonic period (week 1 & 2) (think IMPLANTATION)
When is the greatest risk for birth defects?
Embryonic period (week 3 - 8) (think neurolation, gastrulation, body folding and organogenesis)
Nondisjunction
Failure to separate chromosomes properly during meiosis/mitosis. Chromosomal abnormalities that originate during meiosis are responsible for ~25% of spontaneous abortions and ~10% of major birth defects.
Why is it dangerous for a female to get pregnant after 40 years of age?
increase period of oocyte meiotic arrest = increase risk of exposure to environmental influences
Mosaic Down Syndrome
Nondisjunction during mitosis (not as severe as down syndrome)
Turner’s Syndrome
Birth defect caused by nondisjunction during meiosis.
45, X monosomy
Klinefelter Syndrome
Birth defect caused by nondisjunction during meiosis.
47, XXY trisomy
Infertility
15-30% of couples are infertile.
Males: insufficient sperm numbers, poor motility
Females: Pelvic inflammatory disease (PID), ovulation disorders, endometriosis. cysts, fibroids
In vitro fertilization can be done in these cases
In vitro fertilization
oocytes are harvested laparoscopically, fertilized, and then implanted. success is age-dependent
Mosaicism
Nondisjunction during cleavage (mitosis). Generally less severe (i.e. mosaic down syndrome.
What is the earliest that one can detect pregnancy at home?
8 days. synctiotiotrophobalst secretes enough hCG at day 8 to be detected by a pregnancy test
Ectopic Pregnancy
Implantation outside of uterus. Most common site is the uterine tube. (usual site of implantation is the body of uterus). Implantation near cervix may lead to placenta previa
Placenta Previa
placenta obstructs cervix. often requires a c section.
Molar pregnancy
Trophoblast implants, but embryoblast is absent/incomplete. May produce a tumor called a “hytadiform mole. hCG still secreted = positive pregnancy test.
Hytadiform mole
Trophoblast implants, but embryoblast is absent/incomplete. May produce a tumor called a “hytadiform mole. hCG still secreted = positive pregnancy test.
Spina Bifida
failure of caudal neupore to close properly
Anencephaly
Failure of the rostral neuropore to close properly
When is the greatest risks for birth defects?
Week 4-8
