Twin Pregnancy

Question 1

Describe dizygotic twins?

Answer 1

2/3 of twin pregnancies
Fertilisation of 2 different oocytes by different sperm
(basically two different people)

Question 2

Describe monozygotic twins?

Answer 2

1/3 of twin pregnancies

Identicle twins resulting from mitotic division of single oocyte - sex will always be the same

Question 3

Define chorionicity?

Answer 3

Sharing of the placenta checked via ultrasound within the first trimester

Question 4

Describe four symptoms and signs that may indicate a twin pregnancy?

Answer 4

Hyper-emesis gravidium
Uterus larger for expected dates (palpable by 12 wks)
3(+) x foetal poles palpable
2(+) foetal heart beats auscultated

Question 5

Name seven maternal complications associated with twin pregnancy?

Answer 5

Anaemia
APH/PPP
Pre-eclampsia
Thrombosis
Placental abruption/praevia
Gestational diabetes
Polyhydramnios

Question 6

Describe twin-twin transfusion syndrome?

Answer 6

Only occurs in MCDA twins - typically in 16-22 week

Unequal blood distribution of shared placenta due to vascular anastomosis

Question 7

Describe the effect caused by TTTS on the twins?

Answer 7

1 twin - donor - volume depleted = anaemia/IUGR/oligohydramnios
1 twin - recipient - volume overload = polyhydramnios/macrosomia/polycythaenia/cardiac failure

Question 8

Name 5 risk factors associated with twin pregnancy?

Answer 8

Assisted fertility
FHx
Ethnicity
Increasing parity
Increasing age