Revision - Obs Flashcards
When do ectopic pregnancies typically present?
6-8w gestation
Give 2 causes of cervical motion tenderness
1) PID
2) Ectopic pregnancy
What is the criteria for EXPECTANT management of an ectopic?
- no significant pain
- no foetal heartbeat
- adenexal mass <35mm
- hCG <1500
- unruptured
Criteria for METHOTREXATE management of an ectopic (i.e. instead of surgery)?
- unruptured
- no foetal heartbeat
- hCG <5000
- no significant pain
- adenexal mass <35mm
- confirmed absence of intrauterine pregnancy on US
How is methotrexate given for an ectopic?
IM injection into buttocks
Criteria for surgical management of an ectopic?
- pain
- hCG >5000
- adenexal mass >35mm
- heartbeat
What produces hCG in an intrauterine pregnancy?
The developing syncytiotrophoblast of the pregnancy
Miscarriage vs stillbirth?
Miscarriage: <24w
Stillbirth: >24w
Early vs late miscarriage?
Early: <12w gestation
Late: 12-24w gestation
What is the most common cause of miscarriage?
Anembryonic pregnancy (i.e. blighted ovum)
What are 3 key features in early pregnancy that appear sequentially on a transvaginal US (i.e. as each appears, the previous becomes less relevant in assessing viability of pregnancy)?
1) Mean gestational sac diameter
2) Foetal pole & crown rump length
3) Foetal heartbeat
What are the 2 major risk factors for a miscarriage?
1) increasing maternal age
2) number of previous miscarriages
What is the most common cause of miscarriage in the 1st trimester?
Chromosomal abnormality –> most common is autosomal trisomy (e.g. trisomy 16)
What is the most common single chromosomal abnormality causing miscarriage?
45X karyotype
Define aneuploidy
Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46.
Why is increasing maternal age associated with increasing risk of miscarriage?
Maternal age is related to aneuploidy risk
If the ultrasound scan is inconclusive for an intrauterine pregnancy (i.e. there is a pregnancy of unknown location), what investigation is performed?
Serum hCG
Emergency management of miscarriage?
I.e. patients who present with significant haemorrhage, and/or evidence of haemodynamic instability
) ABCDE approach
2) Urgent senior input from the obstetrics & gynaecology team
3) Speculum exam –> remove products of conception
4) Continued bleeding in a haemodynamically unstable patient warrants surgical management
Why should products of conception be removed in a miscarriage?
Can lead to cervical shock due to vagal stimulation
When is a pregnancy considered viable?
When a foetal heartbeat is present
At what foetal pole and crown-rump length is a foetal heartbeat expected?
≥7mm
When there is a crown-rump length of 7mm or more, without a fetal heartbeat, when is the pregnancy diagnosed as non-viable?
The scan is repeated after one week before confirming a non-viable pregnancy.
Note - can have a pregnancy of unknown viability where size may be 7mm but too small to see foetal heartbeat yet.
But if >7mm with no heartbeat, this is diagnostic of loss of pregnancy.
At what mean gestational sac diameter is a foetal pole expected?
≥25mm
When there is a mean gestational sac diameter of 25mm or more, without a fetal pole, what happens?
The scan is repeated after one week before confirming an ANEMBRYONIC pregnancy.
Is an US helpful <6w gestation?
No - pregnancy will be too small to be seen.
During expectant management, when can a miscarriage be confirmed?
A repeat urine pregnancy test should be performed 3 weeks after bleeding and pain settle to confirm the miscarriage is complete.
Management of miscarriages less than 6 weeks gestation?
Expectant
At what gestational age should you refer a woman to EPAU?
> 6 weeks gestation
When should you refer a woman to early pregnancy assessment service (EPAU)?
1) Positive pregnancy test (>6 weeks gestation)
AND
2) Bleeding
What drug is used in medical management of a miscarriage?
Misoprostol (vaginal suppository or oral dose)
What class of drug is misoprostol?
Prostaglandin analogue
Role of misoprostol in miscarriage?
Prostaglandin analogue
Causes cervical softening & stimulates uterine contractions
What drug is given before surgical management of a miscarriage?
Prostaglandins (misoprostol) –> to soften cervix
What are the 2 options for surgical management of a miscarriage?
1) Manual vacuum aspiration under local anaesthetic as an outpatient
2) Electric vacuum aspiration under general anaesthetic
Who is manual vacuum aspiration more appropriate for?
Women that have previously given birth (parous women).
How many weeks gestation must women be to undergo manual vacuum aspiration?
Must be BELOW 10 weeks gestation
Who should surgical management of miscarriage be performed in?
Patients with significant bleeding who have retained products of conception.
Also used when medical management or expectant management has been unsuccessful.
What is ‘recurrent miscarriage’ defined as ?
3 or more
What is the increased risk of having a subsequent miscarriage after having:
a) 1 miscarriage
b) 2 miscarriages
c) 3 miscarriages
a) no increased risk
b) 25%
c) 40%
What are the two types of molar pregnancy?
1) complete
2) partial
What occurs in a ‘complete’ molar pregnancy?
Occurs when TWO sperm cells fertilise an ovum that contains NO genetic material (an empty ovum).
These sperm then COMBINE genetic mterial and the cells start to divide and grow into a TUMOUR.
NO foetal material will form.
What occurs in a ‘partial mole’ pregnancy?
Occur when TWO sperm fertilise a NORMAL ovum (containing genetic material) and the cells start to divide and grow into a tumour.
SOME foetal material may form.
What are some differences in presentation between a molar pregnancy and a normal pregnancy?
In a molar:
- More severe morning sickness
- Vaginal bleeding
- Increased enlargement of uterus
- Abnormally high hCG
- Thyrotoxicosis
How can a molar pregnancy lead to thyrotoxicosis?
hCG can mimic TSH and stimulate the thyroid to produce excess T3 and T4
What US characteristic appearance can be seen in a molar pregnancy?
Characteristic “snowstorm appearance” of pregnancy.
Management of molar pregnancy?
1) Evacuation of uterus to remove mole –> Products of conception then sent for histological examination to confirm molar pregnancy
2) Monitor hCG levels until normal
3) Mole can occasionally metastasise and may require systemic chemotherapy
What two pharmacological agents are used in a MEDICAL abortion?
1) Mifepristone
2) Misoprostol –> 1 – 2 day later
What class of drug is Mifepristone?
Anti-progestogen
How does Mifepristone work in an abortion?
Mifepristone is an anti-progestogen medication that blocks the action of progesterone –> halting the pregnancy and relaxing the cervix.