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.
When is Misoprostol given in abortion?
Given 1-2 days after Mifepristone
From 10 weeks gestation –> additional misoprostol doses (e.g. every 3 hours) are required until expulsion.
How does Misoprostol work in abortion?
Prostaglandins soften the cervix and stimulate uterine contractions.
When should Rhesus negative women having a medical abortion have anti-D prophylaxis?
Rhesus negative women with a gestational age of 10 weeks or above
What are the 2 surgical options for surgical abortion?
1) Cervical dilatation and suction of the contents of the uterus (usually up to 14 weeks)
2) Cervical dilatation and evacuation using forceps (between 14 and 24 weeks)
How is an abortion confirmed as complete?
A urine pregnancy test is performed 3 weeks after the abortion
When does N&V in pregnancy typically start? When does it peak?
Starts around 1st trimester and peaks 8-12 weeks gestation.
What produces hCG in pregnancy?
Placenta
What hormone is thought to be the cause of N&V in pregnancy?
hCG (theoretically, higher levels of hCG result in worse symptoms)
What type of pregnancies is N&V more severe in?
1) Molar pregnancies
2) Multiple pregnancy (e.g. twins, triplets)
Due to the higher hCG levels.
Also tends to be worse in 1st pregnancy, overweight/obese women and those with a FH of NVP.
What is the criteria for the RCOG guideline for diagnosising hyperemesis gravidarum?
Protracted N&V of pregnancy plus:
1) Weight loss >5% compared to pre-pregnancy weight
2) Electrolyte imbalances
3) Dehydration
What score is used to assess the severity of hyperemesis gravidarum?
Pregnancy-Unique Quantification of Emesis (PUQE) score.
What PUQE score indicates SEVERE hyperemesis gravidarum?
> 12
1st line pharmacological management of hyperemesis gravidarum?
In order of preference:
1) Prochlorperazine (stemetil)
2) Cyclizine
3) Ondansetron
4) Metoclopramide
Mild cases of hyperemesis gravidarum can be managed with oral antiemetics at home.
When should admission be considered?
1) Unable to tolerate oral antiemetics or keep down any fluids
2) More than 5 % weight loss compared with pre-pregnancy
3) Ketones are present in the urine on a urine dipstick (2 + ketones on the urine dipstick is significant)
4) Other medical conditions need treating that required admission
Complications of hyperemesis gravidarum?
1) Dehydration, weight loss & electrolyte imbalances
2) acute kidney injury
3) Wernicke’s encephalopathy
4) oesophagitis, Mallory-Weiss tear
5) venous thromboembolism
Medical mx of a missed miscarriage?
Oral mifepristone
followed by
Misoprostol 48h later
Medical mx of an incomplete miscarriage?
Single dose of misoprostol
Location of ectopic pregnancies that are most prone to rupture?
Isthmus
Why can normal pregnancy cause a raised ALP?
Placental production of ALP
What is ondansetron use during pregnancy associated with a small increased risk of?
Cleft palate/lip
Defien gravida
The TOTAL number of pregnancies a woman has had
Define parity
number of times the woman has given birth after 24 weeks gestation, regardless of whether the foetus was alive or stillborn
What is the 1st trimester?
From start of pregnancy to 12 weeks gestation
What is the 2nd trimester
13w to 26w
What is the 3rd trimester?
27w to birth
When do foetal movements begin?
Around 20w gestation
What are the 5 key appointments during pregnancy? When do they occur?
1) Booking clinic: 8-12w
2) Dating scan: 10-13+6w
3) Down’s syndrome screening: 11-13+6
4) Antenatal appt: 16w
5) Anomaly: 18-20+6w
Nuchal thickness in Down’s syndrome?
Down’s syndrome is one cause of a nuchal thickness > 6mm
What maternal blood tests are done in Down’s syndrome screening (combined test) ?
1) b-hCG
2) pregnancy-associated plasma protein-A (PAPPA)
What maternal blood test results indicates a greater risk of Down’s syndrome?
1) Higher beta-hCG
2) Lower PAPPA
What are the 3 options for screening in Down’s syndrome?
1) Combined test
2) Triple test
3) Quadruple test
When does a triple test screening for Down’s syndrome occur?
14-20w gestation
What does a triple test screening for Down’s syndrome involve?
Maternal blood tests ONLY:
1) hGG (higher)
2) AFP (lower)
3) Serum oestriol uE3 (lower)
What is involved in a quadruple test Down’s syndrome?
identical to triple test BUT also includes maternal blood testing for inhibin-A (higher result indicates greater risk)
The screening tests for Down’s syndrome provide a risk score for the foetus having Down’s syndrome.
What risk leads to a woman being offered further investigations?
1 in 150
What are the next investigations for Down’s syndrome?
What do these tests involve?
Amniocentesis or chorionic villus sampling
Normal folic acid dose pre pregnancy?
400mcg daily
When should you take folic acid in pregnancy?
Pre-conception up to 12w gestation –> reduce risk of neural tube defects
What does chorionic villus sampling involve?
US guided biopsy of placental tissue
Performed <15w gestation
What does amniocentesis involve?
US guided aspiration of amniotic fluid
Used later in pregnancy once there is enough amniotic fluid to make it safer to take a sample
Why should pregnant women avoid unpasteurised dairy or blue cheese?
risk of listeriosis (a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes)
What features can be seen in foetal alcohol syndrome?
1) microcephaly (small head)
2) thin upper lip
3) smooth flat philtrum (groove between the nose and upper lip)
4) short palpebral fissure (short horizontal distance from one side of the eye to the other)
5) learning disability
6) behavioural difficulties
7) Hearing and vision problems
8) Cerebral palsy
Can you fly in pregnancy? Up to what dates in:
a) a single pregnancy
b) in a twin pregnancy
a) 37 weeks
b) 32 weeks
A set of booking bloods are taken at the booking clinic. What bloods are taken?
1) Blood groups, antibodies & rhesus status
2) FBC for anaemia
3) Screening for thalassaemia (all women) and sickle cell (high risk women)
4) HIV, syphilis & hep B
Other investigations at booking clinic?
1) Weight, height and BMI
2) Urine for protein and bacteria
3) Blood pressure
How does levothyroxine need to be adjusted in pregnancy?
Dose needs to be increased during pregnancy (usually 30-50%)
What are 3 classes of HTN drugs that may cause congenital abnormalities?
1) ACEi e.g. ramipril
2) ARBs e.g. losartan
3) Thiazide and thiazide-like diuretics e.g. indapamide
What are 3 classes of HTN drugs that are NOT known to be harmful in prengnacy?
1) Labetalol: a beta blocker (although other beta blockers may have an adverse effect)
2) Calcium channel blockers (e.g. nifedipine)
3) Alpha blockers (e.g. doxazosin)
How should epilepsy be controlled BEFORE becoming pregnancy?
Epilepsy should be controlled with a single anti-epileptic drug before becoming pregnant
What can phenytoin cause in pregnancy?
causes cleft lip and palate
What is 1st line DMARD for RA in pregnancy?
Hydroxychloroquine
Maternal complications of gestational diabetes?
1) Increased risk of HTN
2) Increased risk of pre-eclampsia
When should those AT RISK of gestational diabetes (i.e. risk factors) be screened?
OGTT at 24-28 weeks gestation
When should those with previous gestational diabetes be screened?
1) OGTT soon after booking clinic
2) 2nd test at 24-28 weeks gestation if first test is normal
OGTT results for gestational diabetes?
gestational diabetes is diagnosed if either:
1) fasting glucose is >/= 5.6 mmol/L
2) 2 hour glucose is >/= 7.8 mmol/L
Remember the cutoff for gestational diabetes as 5-6-7-8.
What 3 features may suggest gestational diabetes
1) large for dates foetus
2) polyhydramnios
3) glucose on urine dipstick
Mx of results of OGTT test in gestational diabetes screening:
a) ≥7mmol/l
b) <7mmol/l
c) >6mmol/l + macrosomia (or other complications)
a) start insulin
b) trial of diet & exercise for 1-2 weeks, add metformin, then add insulin (if targets aren’t met)
c) start insulin +/- metformin
What can be suggested as an alternative for women who decline insulin or cannot tolerate metformin?
Glibenclamide (a sulfonylurea)
Is pre-existing diabetes an indication for high dose folic acid (5mg)?
Yes
Is gestational diabetes managed with short-acting or long-acting insulin?
Short acting
Rhesus-D positive vs rhesus-D negative in pregnancy?
Rhesus-D positive –> do NOT need any additional treatment during pregnancy.
Rhesus-D negative –> further management required
How does anti-D medication work in rhesus incomptability?
1) Attaches itself to the rhesus-D antigens on the fetal RBCs in the mothers circulation, causing them to be destroyed.
2) This prevents the mother’s immune system recognising the antigen and creating it’s own antibodies to the antigens
3) It acts as a prevention for the mother becoming sensitised to the rhesus-D antigen.
Anti-D injections are given routinely on what two occasions?
1) 28 weeks gestation
2) Birth (if the baby’s blood group is found to be rhesus-positive)
When should anti-D be given in a sensitisation event?
Within 72h
The Kleinhauer test is performed in rhesus-negative women.
a) when?
b) what is this?
c) purpose?
a) after any potential sensitising event after 20w gestation
b) checks how much fetal blood has passed into the mother’s blood during a sensitisation event
c) assess whether further doses of anti-D is required
What does the Kleihauer test involve?
1) The Kleihauer test involves adding acid to a sample of the mother’s blood.
2) Foetal Hb is naturally more resistant to acid, so that they are protected against the acidosis that occurs around childbirth.
3) Therefore, fetal haemoglobin persists in response to the added acid, while the mothers haemoglobin is destroyed.
4) The number of cells still containing haemoglobin (the remaining fetal cells) can then be calculated.
What is the leading cause of INDIRECT maternal death during or up to six weeks after the end of pregnancy?
Cardiac disease
What is the leading cause of DIRECT maternal death during or up to six weeks after the end of pregnancy?
VTE
Define postpartum haemorrhage (volume)
≥500ml
Define major obstetric haemorrage (volume)
≥2500ml
What is the leading cause of maternal mortality in the UK?
Maternal illness
Who would be offered Hep C screening?
History of drug abuse or obstetric cholestasis
Who would be offered Chlamydia screening at booking scan?
<25 y/o
