Reproduction Flashcards
(13 cards)
Q: What is the key difference between PGD and PGS in IVF?
A:
• PGD: Detects specific genetic disorders (e.g., cystic fibrosis) in embryos of carrier parents
• PGS: Screens for chromosomal aneuploidies in embryos, used in advanced maternal age or recurrent IVF failure
Q: What are 3 high-yield IVF adjuncts and their roles?
A:
• EmbryoGlue: Hyaluronic acid–based medium to improve implantation
• Assisted hatching: Laser-thinning of zona pellucida to help embryo escape
• Time-lapse imaging: Continuous embryo monitoring to select best quality embryo
Q: What determines the type of monozygotic twin pregnancy?
A:
The day of embryonic split:
• 0–3 days = dichorionic diamniotic
• 4–8 days = monochorionic diamniotic
• 8–13 days = monochorionic monoamniotic
• 13 days = conjoined twins
Q: What is Twin-to-Twin Transfusion Syndrome (TTTS)?
A:
A complication of monochorionic twins due to shared placental circulation, leading to:
• Donor twin: anemia, growth restriction, oligohydramnios
• Recipient twin: polycythemia, heart failure, polyhydramnios
Q: What is the highest-risk twin pregnancy and why?
A:
Monoamniotic monochorionic twins – risk of cord entanglement, fetal demise, and TTTS due to shared sac and placenta
Q: What hormonal change triggers ovulation?
A:
A surge in LH, triggered by positive feedback from rising estrogen levels, causes ovulation around Day 14 of the cycle
Q: What is the role of progesterone in the menstrual cycle and pregnancy?
A:
• Prepares endometrium for implantation (secretory phase)
• Maintains early pregnancy
• Inhibits GnRH to suppress LH surge
Q: Which hormone increases significantly post-menopause and why?
A:
FSH, due to reduced negative feedback from estrogen; it’s used as a diagnostic marker for menopause
Q: What is the functional fetal-maternal interface of the placenta and how is it formed?
A:
Tertiary chorionic villi, formed by Week 3, contain fetal capillaries and exchange nutrients with maternal blood in intervillous spaces
Q: What is the role of the chorion frondosum and decidua basalis?
A:
Together, they form the functional placenta:
• Chorion frondosum = fetal contribution
• Decidua basalis = maternal contribution
Q: What maternal immune adaptation occurs during pregnancy?
Shift to Th2-dominant immunity:
• Promotes maternal tolerance to fetal antigens
• Reduces cytotoxic T-cell activity
What is the most common cause of ambiguous genitalia in 46,XX neonates?
A: Congenital adrenal hyperplasia (21-hydroxylase deficiency)
What distinguishes complete androgen insensitivity syndrome (CAIS)?
46,XY karyotype, female external genitalia, no uterus, no pubic/axillary hair
