Miscarriage

Question 1

Miscarriage

Answer 1

Miscarriage is the spontaneous loss of an intrauterine pregnancy before 24 weeks gestation. It occurs in approximately 10 – 24% of all clinical pregnancies

Question 2

Risk factors for miscarriage

Answer 2

Increasing maternal age and the number of previous miscarriages.

Most miscarriages (~80%) are diagnosed under 13 weeks, with the risk of miscarriage decreasing as gestational age increases.

Question 3

Most common cause of miscarriage in the 1st trimester

Answer 3

Chromosomal abnormality (50-60%).

Autosomal trisomy is the most common abnormality (e.g. trisomy 16). The most common single chromosomal anomaly is 45X karyotype.

Question 4

Most common cause of miscarriage in the 2nd trimester

Answer 4

An incompetent cervix (e.g. due to previous cervical surgery) or systemic maternal illness.

Question 5

There are 5 types of miscarriage; what are they?

Answer 5

1. Threatened miscarriage
2. Inevitable miscarriage
3. Incomplete miscarriage
4. Complete miscarriage
5. Other types of miscarriage:

Question 6

Threatened miscarriage

Answer 6

Occurs when there is vaginal bleeding but the cervical os is closed, and ultrasound shows a viable intrauterine pregnancy.

Most threatened miscarriages do not result in the loss of the pregnancy.

Question 7

Inevitable miscarriage

Answer 7

Refers to vaginal bleeding with an open cervical os, either with or without cramping abdominal pain. In this situation, pregnancy loss will occur (i.e. inevitable).

Question 8

Incomplete miscarriage

Answer 8

Occurs when there is vaginal bleeding, an open cervical os and products of conception are seen on examination.

Question 9

Complete miscarriage

Answer 9

When the products of conception have passed, the cervical os is closed and ultrasound shows an empty uterine cavity.

Question 10

Other types of miscarriage apart from threatened, inevitable, incomplete & complete.

Answer 10

a. Missed miscarriage: the presence of a nonviable intrauterine pregnancy that has not yet resulted in symptoms or the passage of the products of conception.
b. Recurrent miscarriage: the occurrence of three or more miscarriages.

Question 11

What is a missed miscarriage?

Answer 11

The presence of a nonviable intrauterine pregnancy that has not yet resulted in symptoms or the passage of the products of conception.

Question 12

Examinations for miscarriage

Answer 12

Vital signs recorded using an obstetric or maternal early warning chart.

Abdominal examination should be performed to assess for signs of an acute abdomen

A speculum to assess the cervical os, rule out other sources of bleeding (e.g. cervical/vaginal pathology), quantify the bleeding and assess for visible products of conception.

If an ectopic pregnancy is suspected, a bimanual examination should also be performed.

Question 13

Laboratory tests for management of miscarriage

Answer 13

Full blood count
Beta-HCG:
Group and save / cross-match: if significant bleeding
Antibody screen: rhesus negative women

Question 14

Why should an antibody screen be done for surgical procedures (miscarriage, labour)?

Answer 14

Rhesus negative women undergoing a surgical procedure to manage miscarriage will require anti-D rhesus prophylaxis

Question 15

Imaging in miscarriage

Answer 15

A transvaginal ultrasound

If the ultrasound scan is inconclusive for an intrauterine pregnancy (i.e. there is a pregnancy of unknown location), serial beta-HCG measurements are performed.

Question 16

How much should serum beta-HCG increase in a progressing pregnancy?

Answer 16

Should increase by more than 63% in 48 hours in a progressing pregnancy.

Beta-HCG levels that fall by more than 50% in 48 hours indicate a failing pregnancy (potential miscarriage).

Beta-HCG levels that fall by less than 50%, or fail to rise by more than 63%, over 48 hours require clinical review to exclude an ectopic pregnancy.

Question 17

Emergency management of haemodynamically unstable patient in miscarriage.

Answer 17

Patients who present with significant haemorrhage, and/or evidence of haemodynamic instability, require an ABCDE approach.

A speculum examination should be performed, and products of conception should be removed.

Continued bleeding in a haemodynamically unstable patient warrants surgical management.

Question 18

Why are products of conception in the cervical os dangerous in miscrriage?

Answer 18

Products of conception in the cervical os can lead to cervical shock due to vagal stimulation

Question 19

What are the surgical management options for miscarriage?

Answer 19

Manual vacuum aspiration

Surgical evacuation

Question 20

Manual vacuum aspiration

Answer 20

under local anaesthetic. involves manual suction aspiration of the uterus

Question 21

Surgical evacuation

Answer 21

under general anaesthetic, an electronic suction device is used to remove products of conception

Question 22

When is surgical management of miscarriage required?

Answer 22

Should be performed in patients with significant bleeding who have retained products of conception. Surgical management is also used when medical management or expectant management has been unsuccessful.

Rhesus negative patients undergoing surgical management of miscarriage should be given anti-D rhesus prophylaxis.

Question 23

Medical management of miscarriage

Answer 23

Involves the use of a prostaglandin agent (misoprostol) to induce uterine contractions and effacement (empty) of the cervix.

Question 24

Example of prostaglandin agent

Answer 24

Misoprostol

Question 25

Expectant management of miscarriage

Answer 25

Involves waiting for spontaneous passage of the products of conception, without any medical or surgical intervention.

A pregnancy test should be performed three weeks after expectant management providing pain and bleeding settles. If positive, imaging for retained products of conception will be required.

Question 26

What is expectant management?

Answer 26

Involves waiting for spontaneous passage of the products of conception, without any medical or surgical intervention.

Question 27

Recurrent miscarriage

Answer 27

Defined as three or more miscarriages. These patients require a specialist review to assess for an underlying cause of miscarriage.

Question 28

Causes of recurrent miscarriage

Answer 28

1. Increased maternal age
2. Parental genetic factors
3. Thrombophilic disorders
4. Endocrine disorders (diabetes, thyroid disorders, PCOS)
   5, Structural uterine abnormalities

Question 29

Investigations for recurrent miscarriage

Answer 29

1. Cytogenetic analysis performed on the products of conception of the third and any subsequent miscarriages
2. Parental karyotyping and genetic counselling
3. Blood tests: HbA1c, antiphospholipid/thrombophilia screen, thyroid function tests
4. Pelvic ultrasound

Question 30

When is cytogenetic analysis performed in recurrent miscaariage?

Answer 30

Performed on the products of conception of the third and any subsequent miscarriages

Question 31

Complications of miscarriage

Answer 31

1, Infection
2, Retained products of conception:
3, Asherman’s syndrome
4. Psychological impact

Question 32

Risk of occurrence of miscarriage

Answer 32

No increased risk of having another miscarriage after having one miscarriage.

After two miscarriages, the risk of having a subsequent miscarriage is 25%.

After three miscarriages, the risk is approximately 40%.