High-risk pregnancies — Flashcards

Flashcard 41: How many chorions and amnions develop when a zygote splits after Day 12?

Answer: 1 chorion, 1 amnion, conjoined twins

Flashcard 42: What are the characteristic clinical features of Fetal Alcohol Syndrome (FAS)?

Answer: Intellectual disability, microcephaly, facial dysmorphism (smooth philtrum, thin upper lip), and growth retardation.

Extra: Fetal Alcohol Syndrome (FAS) is the leading cause of preventable intellectual disability. Key clinical features: 1. Facial abnormalities: Smooth philtrum, thin vermilion border (upper lip), short palpebral fissures. 2. Growth: Pre- and postnatal growth restriction. 3. CNS: Microcephaly, intellectual disability, ADHD. 4. Other: Cardiac defects (VSD), limb deformities. Mechanism: Alcohol crosses the placenta and inhibits cell migration and proliferation.

Flashcard 43: Dizygotic twins arise from _____ egg(s) and _____ sperm.

Answer: 2

Flashcard 44: Monozygotic twins arise from _____ egg and _____ sperm.

Answer: 1

Flashcard 45: How many chorions and amnions develop when a zygote splits between Day 0-4?

Answer: 2 chorions, 2 amnions

Flashcard 46: How many chorions and amnions develop when a zygote splits between Day 4-8?

Answer: 1 chorion, 2 amnions

Flashcard 47: How many chorions and amnions develop when a zygote splits between Day 8-12?

Answer: 1 chorion, 1 amnion

Flashcard 48: gonads (ovaries and testes)

Answer: mesoderm

Flashcard 49: Deformation (definition)

Answer: extrinsic disruption; occurs after embryonic period

Flashcard 50: Definition of Malformation (Organogenesis)

Answer: Intrinsic disruption of development; occurs during the embryonic period (weeks 3–8).