Miscarriage

Question 1

What is the definition of miscarriage?

Answer 1

the spontaneous termination of pregnancy before 24 weeks gestation

spontaneous termination after 24 weeks = stillbirth

Question 2

What is an early and late miscarriage?

Answer 2

early:

• occurs in the first 12 weeks of pregnancy

late:

• occurs between 12 - 24 weeks gestation

Question 3

What is a missed miscarriage?

Answer 3

• the foetus is no longer alive
• no symptoms have occurred
• often diagnosed through routine antenatal scans

also called a “silent miscarriage”

Question 4

What is a threatened miscarriage?

Answer 4

• there is vaginal bleeding with a closed cervix
• the foetus is still alive
• this does not necessarily mean that the patient will go on to have a miscarriage

Question 5

What is an inevitable miscarriage?

Answer 5

• there is a diagnosed non-viable pregnancy
• there is vaginal bleeding and an open cervical os
• the pregnancy will proceed to an incomplete or complete miscarriage

• pregnancy tissue still remains within the uterus at this stage

Question 6

What is an incomplete miscarriage?

Answer 6

• miscarriage occurs and bleeding has begun
• the cervical os is open
• there are retained products of conception in the uterus following miscarriage

Question 7

What is a complete miscarriage?

Answer 7

• a full miscarriage has occurred
• there are NO products of conception left in the uterus
• the bleeding has now stopped and the cervix is closed

Question 8

What is an anembryonic pregnancy?

Answer 8

a gestational sac is present but it contains no embryo

Question 9

How is a miscarriage diagnosed?

Answer 9

transvaginal USS

Question 10

What 3 features are looked for on transvaginal US to determine the viability of a pregnancy?

Answer 10

• mean gestational sac diameter
• foetal pole + crown-rump length
• fetal heartbeat

mean gestational sac diameter

these appear sequentially so as each feature develops, the previous becomes less relevant in determining viability of a pregnancy

Question 11

When is a fetal heartbeat expected to be seen?

What does this mean for the pregnancy?

Answer 11

• fetal heartbeat is expected to be seen when CRL is 7mm or more
• the presence of a heartbeat means that the pregnancy is viable

Question 12

What is done when there is a CRL < 7mm and NO fetal heartbeat?

Answer 12

the scan is repeated after 1 week to ensure that a heartbeat develops

Question 13

What is done when the CRL is > 7mm and the fetal heartbeat is not present?

Answer 13

• the scan is repeated after 1 week
• if the fetal heartbeat still cannot be seen, this is deemed a non-viable pregnancy

Question 14

How is an anembryonic pregnancy diagnosed on transvaginal USS?

Answer 14

• a fetal pole is expected once mean gestational sac diameter is 25mm or more
• if the MGSD is >25mm and there is no fetal pole, scan is repeated after 1 week
• if the fetal pole is still not present, this is an anembryonic pregnancy

Question 15

What is the management for miscarriage occurring before 6 weeks gestation?

Answer 15

expectant management

• this involves awaiting the miscarriage without investigations / treatment
• as long as they do not have pain / complications / RFs

a scan is not performed as the pregnancy will be too small to be seen at this stage

Question 16

How can miscarriage be confirmed following expectant management?

Answer 16

• a repeat urine pregnancy test is performed after 7-10 days
• miscarriage is confirmed if it is negative

if bleeding continues or pain occurs, further investigation is needed

Question 17

What is the first stage in management of a suspected miscarriage after 6 weeks gestation?

Answer 17

• women are referred to an early pregnancy assessment unit if they have a positive PT and bleeding
• an USS is arranged to confirm the location + viability of the pregnancy
• this can also exclude ectopic pregnancy

Question 18

What are the 3 options for managing a miscarriage after 6 weeks gestation?

Answer 18

• expectant management
• medical management with misoprostol
• surgical management

Question 19

When is expectant management recommended following miscarriage > 6 weeks gestation?

Answer 19

• first-line option for women without RFs for heavy bleeding or infection
• 1-2 weeks are given to allow the miscarriage to occur spontaneously
• repeat urine PT performed 3 weeks after bleeding + pain settles to confirm the miscarriage is complete

Question 20

What is involved in medical management of a miscarriage?

Answer 20

• misoprostol is given to expedite the process of miscarriage
• this can be given orally or as a vaginal suppository

Question 21

How does misoprostol work?

Answer 21

• it is a prostaglandin analogue
• it binds to prostaglandin receptors to activate them
• this results in softening of the cervix and stimulation of uterine contractions

Question 22

What are the side effects of misoprostol?

Answer 22

• heavier bleeding
• pain
• vomiting
• diarrhoea

Question 23

What are the 2 surgical options for managing miscarriage?

Answer 23

• manual vacuum aspiration (MVA) under local anaesthetic
• electric vacuum aspiration (EVA) under general anaesthetic

Question 24

What is given to all patients prior to surgical management of miscarriage?

Answer 24

misoprostol

• prostaglandins are given to soften the cervix prior to surgical management

Question 25

What is involved in manual vacuum aspiration (MVA)?

Answer 25

* **local anaesthetic** is applied to the cervix * a tube attached to a syringe is inserted through the cervix into the uterus * the syringe is used to **manually aspirate** the contents of the uterus

Question 26

What are the criteria for performing MVA?

Answer 26

* women must be **below 10 weeks gestation** * it is more appropriate for **parous women** (who have previously given birth)

Question 27

What is involved in electric vacuum aspiration?

Answer 27

* performed under **general anaesthetic** * the **cervix is gradually widened** using dilators * the products of conception are removed through the cervix using an **electric-powered vacuum**

Question 28

What needs to be administered to women prior to surgical management of miscarriage?

Answer 28

**anti-D** must be given to **rhesus negative** women prior to the procedure

Question 29

What is the associated risk of an incomplete miscarriage?

Answer 29

* the **retained products of conception** remain in the uterus after conception * this may be **fetal** or **placental tissue** * retained products create a **risk of infection**

Question 30

What are the 2 options for management of an incomplete miscarriage?

Answer 30

* medical management with misoprostol * surgical management

Question 31

What is involved in the surgical management of incomplete miscarriage?

Answer 31

**evacuation of retained products of conception (ERPC)** * involves general anaesthetic * the cervix is gradually widened using dilators * the retained products are removed using **vacuum aspiration + curettage** (scraping)

Question 32

What is the main risk associated with ERPC?

Answer 32

**endometritis** following the procedure | (infection of the endometrium)

Question 33

How is recurrent miscarriage defined?

Answer 33

when an individual has **3 or more consecutive miscarriages**

Question 34

When are investigations for the underlying cause of miscarriage initiated?

Answer 34

* after **3 or more first-trimester** miscarriages OR * after **1 or more second-trimester** miscarriages

Question 35

What are the potential underlying causes of recurrent miscarriage?

Answer 35

* **idiopathic** (especially in older women) * **antiphospholipid syndrome** * hereditary **thrombophilias** * **uterine abnormalities** * genetic factors in parents * chronic histiocytic intervillositis * chronic diseases ## Footnote common chronic diseases = uncontrolled thyroid disease, diabetes + SLE

Question 36

What is antiphospholipid syndrome?

Answer 36

* an autoimmune disorder associated with **antiphospholipid autoantibodies** * the patient is in a **hypercoagulable state** * it is associated with increased risk of **thrombosis** + **complications during pregnancy**

Question 37

Who tends to be affected by antiphospholipid syndrome?

Answer 37

* it typically affects **women** around the **age of 30-40** * it is associated with other autoimmune conditions, particularly **systemic lupus erythematosus** (SLE)

Question 38

How is antiphospholipid syndrome diagnosed and managed?

Answer 38

* test for the presence of **antiphospholipid antibodies** * managed with BOTH **low dose aspirin** and **low molecular weight heparin** (LMWH) * this manages the risk of miscarriage and VTE

Question 39

What hereditary thrombophilias are most commonly associated with recurrent miscarriage?

Answer 39

* Factor V Leiden * factor II (prothrombin) gene mutation * protein S deficiency

Question 40

What uterine abnormalities can result in recurrent miscarriage?

Answer 40

* uterine septum * unicornate uterus * bicornate uterus * didelphic uterus * cervical insufficiency * fibroids

Question 41

What is a septate uterus?

Answer 41

a **thin tissue membrane (septum)** runs down the middle of the uterus, splitting it into **2 parts**

Question 42

What is a unicornate uterus?

Answer 42

* a congenital abnormality in which **only half of the uterus forms** * there is only **one working fallopian tube** * there is a **smaller uterine cavit**y ## Footnote also known as a "single horn" uterus

Question 43

What is a bicornate uterus?

Answer 43

a uterus that is divided into **2 parts** by a **deep indentation** at the top ## Footnote also called a "heart-shaped uterus"

Question 44

What is a didelphic uterus?

Answer 44

* the presence of **2 uteruses** * also called a "double uterus" * the individual also has **2 cervixes** ## Footnote this is different to a bicornate uterus, in which there is only one cervix

Question 45

What is chronic histiocytic intervillositis?

Answer 45

* **histiocytes + macrophages** build up in the placenta * the **mother's immune system reacts abnormally** to the pregnancy * this causes **inflammation** + adverse outcomes * causes recurrent miscarriage (usually 2nd trimester), IUGR + IUD ## Footnote the condition is poorly understood and is rare

Question 46

How is chronic histiocytic intervillositis diagnosed?

Answer 46

**placental histology** * shows infiltrates of **mononuclear cells** in the **intervillous spaces** * it commonly **recurs**, so needs specialist management

Question 47

What investigations are performed in recurrent miscarriage?

Answer 47

* antiphospholipid antibodies * testing for hereditary thrombophilias * pelvic USS * genetic testing of parents * genetic testing of products of conception from 3rd or future miscarriages