Recurrent miscarriage Flashcards
Define recurrent miscarriage
> 3 consecutive pregnancies that end in miscarriage of the fetus before 24 weeks gestation
What percentage of women of reproductive age suffer from recurrent miscarriage?
1-2%
List some causes of recurrent miscarriage
Antiphospholipid syndrome
Genetic factors - parental chromosomal rearrangements or embryonic chromosomal abnormalities
Endocrine - DM, thyroid disease and PCOS
Anatomical factors - uterine malformations, cervical weakness or acquired uterine abnormalities
Infective agents
Inherited thrombophilias
What does antiphospholipid syndrome refer to?
Association between antiphospholipid antibodies and vascular thrombosis or pregnancy failure/complication
What percentage of women with recurrent miscarriage have antiphospholipid syndrome
15%
What is the live birth rate for women with antiphospholipid syndrome and no pharmacological intervention
10%
Describe parental chromosomal rearrangements
In approx 2-5% of couples with recurrent miscarriage, one of the partners carries a balanced reciprocal or robertsonian 1 chromosomal translocation. They are phenotypically normal but their pregnancies are at an increased risk of miscarriage, secondary to an unbalanced chromosomal arrangement
How many miscarriages in recurrent pregnancy loss does embryonic chromosomal abnormalities account for
30-57%
What does a high HBA1c at conception increase the risk of?
Miscarriage and foetal malformation
Describe the mechanisms by which PCOS is thought to increase risk of miscarriage
Insulin resistance
Hyperinsulinemia
Hyperandrogenaemia
List some uterine malformations
Septate
Bicornuate
Arcuate
What is an arcuate uterus?
Dip at the top
What is a septate uterus?
Has a membrane (septum) dividing the inner portion of the uterus
What is a bicornuate uterus?
Uterus appears heart shaped
Describe cervical weakness and how it may lead to miscarriage
Where cervix begins to efface and dilate before pregnancy reaches term
What is the classic history of cervical weakness
Second trimester miscarriage
Preceded by spontaneous rupture of membranes or painless cervical dilatation
List some acquired uterine abnormalities
Adhesions
Fibroids
What is the name of the syndrome which involves adhesions?
Ashermans
What is Ashermans syndrome?
scar tissue on uterus or cervix causing the walls to stick together and reduces the size of the uterus
Which infective agent increases risk of second trimester miscarriage?
Bacterial vaginosis
Which inherited thrombophilias increase the risk of second trimester pregnancy loss
Factor V leiden
Prothrombin gene mutation
Deficiencies of protein C/S and antithrombin 111
List 3 risk factors for recurrent miscarriage
Advanced maternal age
Number of previous miscarriages
Lifestyle
What blood tests would you order when investigating recurrent miscarriage?
Antiphospholipid antibodies
Inherited thrombophilia screen - factor V leiden, prothrombin gene mutation and protein S deficiency
What is required for a diagnosis of antiphospholipid syndrome?
2 positive tests, 12 weeks apart for either lupus anticoagulant, anticardiolipin antibodies or anti-B2 glycoprotein antibodies
What genetic tests would you order for recurrent miscarriage?
Cytogenetic analysis - examines for any chromosomal abnormalities in the POC of >3rd miscarriage
Parental peripheral blood karyotyping - indicated when testing POC reports unbalanced structural chromosomal abnormality. Done on both parents
What imaging is done in recurrent miscarriage?
Pelvic ultrasound - assess uterine anatomy. If anomalies suspected then further investigations such as hysteroscopy, laparoscopy or 3d pelvic US
Describe the management for recurrent miscarriage caused by genetic abnormalities
Couples with abnormal parental karyotype should be referred to a clinical geneticist
Prognosis of risk of future pregnancies
Familial chromosomal studies
Preimplantation genetic screening with IVF if unexplained recurrent miscarriage
What is the management of recurrent miscarriage caused by cervical weakness?
Cervical cerclage
or serial cervical sonographic surveillance
What is cervical cerclage?
Suture is placed to close the cervix
When might cervical cerclage be indicated?
Previous poor obstetric history >3 X 2nd trimester losses
Cervical length shortening on USS
Symptomatic women with premature cervical dilation and exposed foetal membranes in the vagina
List the complications of cervical cerclage
Bleeding
Membrane rupture
Stimulating uterine contractions
How are women with antiphospholipid syndrome managed in pregnancy
Low dose aspirin and low molecular weight heparin therapy
