Multiple pregnancies: Week 3

Question 1

What is a multiple birth?

Answer 1

Y

Question 2

What is the incidence of multiple pregnancies?

Answer 2

Y

Question 3

What are the associated risk factors?

Answer 3

Anaemia
•Pre eclampsia / PIH
•Gestational Diabetes
•Prematurity
•Placental Insufficiency
•Placenta praevia
•PPH
•Trauma associated with fetal manipulation
*Management dependent on chorionicity

Question 4

?What are the causes of dizygotic twinning?

Answer 4

each fetus has its own placenta (either separate or fused), amnion and chorion
.•No single cause but linked to levels of Gonadotropin hormones in the blood.
•Associated factors:
•Race (Nigeria 45/1000 maternities);
•Far East – Lowest (5.6/1000 maternities – Japan);
•Maternal Age;
•Parity;
•Maternal height and weight (the taller and heavy you are, more likely to have non-identical)

Question 5

What are the causes of monozygotic twinning?

Answer 5

With earlier division, you have less complications
monozygotic twinning:The situation is more complex depending on the timing of the division of the ovum:–embryo splits at 3 days - two chorions, two amnions –embryo splits at 4-7 days - single placenta, one chorion, two amnions –embryo splits at 8-12 days - single placenta, one chorion and one amnion (rare) –embryo splits at 13 days - conjoined or Siamese twins (very rare

Question 6

Zygosity

Answer 6

ZYGOSITY•Monozygotic – Uniovular IdenticalSplitting of a zygote during the first 14 days after fertilizationSame SexGenetically IdenticalFactors responsible unknown, however more common following:Ovulation induction, GIFT, IVF;Clomiphene Citrate.No genetic predispositio

Question 7

dizygotic

Answer 7

ZYGOSITY•Dizygotic - Binovular  Non Identical, FraternalResult from the fertilization of two independently released eggs by different spermNo more alike than any other siblings25% - Both Boys25% - Both Girls50 : 50 Boy / Girl•Superfecundation Twins resulting from two coital acts in the same menstrual cycle•SuperfetationTwins resulting from two coital acts in different cycl

Question 8

What are the reason for determining zygosity?

Answer 8

•As part of clinical care;•To provide accurate genetic counselling–Future twins in future pregnancies;–Congenital abnormalities•For the parents / multiples intere