OB Ch. 45: Multifetal Pregnancy

Question 1

Which of the following is increased among multifetal gestations compared to singletons? May have more than 1 answer

a. infant death
b. congenital anomalies
c. gestational diabetes
d. pre-eclampsia
e. permpartum hysterectomy
f. postpartum hysterectomy
g. maternal death
h. depression
i. parental divorce

Answer 1

All except gestational diabetes.

a. infant death
twins 4x
triplets 12x
quadruplets 26x

b. congenital anomalies - risk applies to each fetus
congenital heart defect 12x

d. pre-eclampsia 2x

e. peripartum hysterectomy
twins 3x
triplets/quads 24x

f. postpartum hemorrhage 2x
g. maternal death 2x

h. depression
i. parental divorce

Question 2

Dizygotic twins are technically not twins.

Answer 2

TRUE. dizygotic twinning results from the fertilization of 2 separate ova and not the fertilization of one ovum that subsequently divided

Question 3

Identical twins are monozygotic twins.

Answer 3

False. not technically identical because the there is no true equal sharing of protoplasmic material.

Question 4

give the timing of division after fertilization that would result to the following monozygotic twinning:

diamnionic, dichorionic
diamnionic, monochorionic
mono amnionic, monochorionic
conjoined twins

Answer 4

< 72hours: diamnionic, dichorionic, placenta may be 2 separate or one fused

between 4-8 days: diamnionic, monochorionic

8days: mono amnionic, monochorionic

more than 8 days: conjoined twins

Question 5

monochorionic twins can never be dizygotic.

Answer 5

False.

Monochorionic placenta is monozygotic until proven otherwise.
Dichorionic placenta can be dizygotic or monozygotic.
Monochorionic twins may be monozygotic.

Question 6

Superfetation vs superfecundation:

a. fertilization of 2 ova within the same menstrual cycle but not at the same coitus nor by sperm from the same male
b. occur in mares
c. not known to occurin humans
d. ovulation and fertilization during the course of an established pregnancy

Answer 6

Superfecundation
a. fertilization of 2 ova within the same menstrual cycle but not at the same coitus nor by sperm from the same male

Superfetation

b. occur in mares
c. not known to occurin humans
d. ovulation and fertilization during the course of an established pregnancy

Question 7

Monozygotic twinning is more common than dizygotic twinning.

Answer 7

False

Question 8

monozygotic twinning is affected by race, heredity, maternal age, parity and ART.

Answer 8

False. incidence is generally undefended of demographics except ART use.

Frequency of monozygotic twinning is constant at 1 per 250.

Heredity - racial variations in levels of FSH
maternal family history supersedes paternal

Maternal age
Paradox: declining fertility but increased chances of twinning
4-fold increase between 15-37 years of age
Increasing levels of FSH = increased chance of multiple ova being released
Increase of ART use

Fertility Treatment
Ovulation induction
28.6% twinning rate, 9.3% higher-order rate
Greater number of embryos transferred = Higher rate of multi-fetal gestation

Parity <=4: 8-fold rise
Parity>=5: 20-fold rise

Nutrition
taller, heavier women - 25-30%

Question 9

Greater fecundity and a higher rate of dizygotic twinning have been reported in women who conceive 3 months after stopping OCPs

Answer 9

False. 1 month

Question 10

As the number of fetuses increase, so does the probability of them being male.

Answer 10

false. female