GTG 17: Recurrent Miscarriage

Question 1

what is the definition of recurrent miscarriage, and how many couples does it affect?

Answer 1

The loss of 3 or more consecutive pregnancies, affects 1% couples trying to conceive

Question 2

what percentage second trimester pregnancies miscarry before 24/40?

Answer 2

1-2%

Question 3

what is the age-related risk of miscarriage for women aged:

1. 12-19
2. 20-24
3. 25-29
4. 30-34
5. 35-39
6. 40-44
7. > 45

Answer 3

1. 13%
2. 11%
3. 12%
4. 15%
5. 25%
6. 51%
7. 93%

Question 4

what age group of couples considered at highest risk of miscarriage?

Answer 4

women aged over 35 with man aged over 40

Question 5

Risk of miscarriage increases after each successive pregnancy loss. What is the risk of miscarriage after 3 consecutive miscarriages?

Answer 5

40%

Question 6

what are the 3 main mechanisms by which anti-phospolipid antibodies cause miscarriage?

Answer 6

1. inhibition of trophoblastic function and differentiation
2. activation of complement pathways at the maternal fetal interface, leading to inflammatory response
3. later in pregnancy, thrombosis of uteroplacental vasculature

Question 7

in what percentage of women with miscarriage are antiphospholipid antibodies present?

Answer 7

15%

Question 8

in women with recurrent miscarriage associated with antiphospholipid antibodies, what is the live birth rate with no pharmacological intervention?

Answer 8

10%

Question 9

in what percentage of couples with recurrent miscarriage will one partner carry a balanced structural chromosomal anomaly?

Answer 9

2-5%

commonly balanced reciprocal or robertsonian translocation

Question 10

chromosomal abnormalities of the embryo account for what percentage of recurrent miscarriage?

Answer 10

30-57%

Question 11

what is the prevalence of uterine anomalies in recurrent miscarriage populations?

Answer 11

1.8-37.6%

uterne anomalies more prevalent in second trimester miscarriages

Question 12

what vaginal infection is associated with an increased risk of second trimester miscarriage?

Answer 12

bacterial vaginosis

Question 13

how is antiphospholipid syndrome diagnosed?

Answer 13

2 positive tests- for either lupus or anticardiolipin antibodies- 12 weeks apart. Looking for Ig G +/- Ig M.
Titre>40

Question 14

when should screening for antiphospholipid syndrome take place? After how many miscarriages?

Answer 14

test prior to pregnancy.

after 1 second trimester miscarriage or recurrent 1st trimester miscarriage

Question 15

when should cytogenetic analysis be performed on POC?and in what circumstance would both partners be karyotyped?

Answer 15

cytogenetic analysis for 3rd and subsequent consecutive miscarriages.
both partners karytoyped if unbalanced chromosomal abnormality detected

Question 16

what percentage of couples with recurrent miscarriage have balanced translocations?

Answer 16

2%

Question 17

what are the 3 main inherited thrombophilias associated with miscarriage? In which trimester are these miscarriages more likely to occur?

Answer 17

1. Factor V Leiden
2. Prothrombin (factorII) gene mutation
3. Protein S deficiency
   associated with 2nd tri miscarriages

Question 18

what treatment is given to women with antiphoshpholipid syndrome? By what % does this reduce the miscarriage rate by?

Answer 18

low dose aspirin and LMWH

reduces miscarriage rate by 54%

Question 19

in translocation carriers, what is the chance of achieving a live birth with natural conception compared to chance of live birth with pre-implantation genetic diagnosis + IVF?

Answer 19

50-70% chance live birth with natural conception.

20-30% with IVF

Question 20

what is the chance of successful future pregnancy with supportive care alone, in women with unexplained recurrent miscarriage?

Answer 20

75%