Obstetrics Flashcards
What is the most common site for ectopic pregnancies?
Ampulla of the fallopian tube
What are risk factors for ectopic pregnancy?
Previous ectopic pregnancy
Previous pelvic inflammatory disease
Previous surgery to fallopian tubes
IUD
Older age (>35)
Smoking
IVF
Being under 18 at first sexual intercourse
Black race
What are classic presenting features of an ectopic pregnancy?
Presents at 6-8 weeks
Missed period
Constant pain in right or left iliac fossa
Vaginal bleeding
Lower abdominal or pelvic tenderness
Cervical motion tenderness
Dizziness/syncope (blood loss)
Shoulder tip pain (peritonitis)
What is the management for ectopic pregnancy?
No pain, no visible heartbeat, unruptured, <35mm, HCG < 1500 IU/l = Expectant management
HCG<5000IU/l + combined absense of intrauterine pregnancy = methotrexate
Pain, >35mm, visible heartbeat, HCG > 5000IU/l = surgery –> laparoscopic salpingectomy/salpingotomy
What is the investigation of choice for diagnosing a miscarriage?
Transvaginal US
What is the management of miscarriage?
Less than 6 weeks = Expectant if no pain or signs of ectopic
More than 6 weeks:
Referral to early pregnancy unit
Expectant
Medical –> Misoprostol (softens the cervix and stimulates uterine contractions)
Surgical –> Vacuum aspiration
What is a threatened miscarriage?
Patient presents with vaginal bleeding but the pregnancy is still viable
Cervical os is closed
What is a missed miscarriage?
A gestational sac before 20 weeks that contains a non-viable fetus, without the symptoms of expulsion
May have light vaginal bleeding but no flooding or pain
Cervical os close
What is an inevitable miscarriage?
Heavy vaginal bleed with an open cervical os
Nothing can be done to prevent miscarriage
What is an incomplete miscarriage?
Not all products of conception have been expelled
Pain and bleeding
Open cervical os
What is a complete miscarriage?
Full miscarriage with no remaining products of conception
What is the cause of hyperemesis gravidarum?
In pregnancy, the placenta produces human chorionic gonadotrophin (HCG), which is responsible for nausea and vomiting
Higher levels of HCG (molar pregnancies, multiple pregnancies) lead to more severe symptoms
What is the medical management of hyperemesis gravidarum?
1st line = prochlorperazine
2nd line = cyclizine
3rd line = ondansetron
4th line = metoclopramide
Ranitidine/omeprazole if acid reflux is a problem
What is a hydatidiform mole/molar pregnancy?
A tumour that grows like a pregnancy inside the uterus.
Complete mole = two sperm cells fertilise an empty ovum, and start to divide but do not form any foetal material
Partial mole = two sperm cells fertilise a normal ovum at the same time, now having 3 sets of chromosomes, and divides, may form some foetal material
What factors indicate molar pregnancy instead of normal pregnancy?
More severe morning sickness
Vaginal bleeding
Increased uterine enlargement
Abnormally high HCG
Thyrotoxicosis
What is the management of a molar pregnancy?
Evacuation of the uterus
Send products for histological examination
Follow up and check for metastases
What is the classic triad of pre-eclampsia features?
Hypertension (pregnancy-induced)
Proteinuria
Oedema
What are the risk factors for pre-eclampsia?
High risk:
Pre-existing hypertension
Previous hypertension in pregnancy
Existing autoimmune condition eg. SLE
Diabetes
Chronic kidney disease
Moderate risk:
Older than 40
BMI>35
More than 10 years since last pregnancy
First pregnancy
Multiple pregnancy
Family history of pre-eclampsia
What are the symptoms of pre-eclampsia?
Headache
Visual disturbance
Nausea and vomiting
Upper abdominal or epigastric pain
Oedema
Reduced urine output
Brisk reflexes
What is the management of pre-eclampsia?
Prophylactic aspirin from 12 weeks until birth if 1 high-risk factor or more than 1 moderate-risk factors
Monitoring –> BP, symptoms, urine dipstick
Aim for BP below 135/85
Labetolol (first line medication)
Nifedipine (second line)
Methyldopa (third line)
What is eclampsia?
Seizures associated with pre-eclampsia
What is the management of eclampsia?
IV magnesium sulphate
What does HELLP stand for?
Haemolysis
Elevated Liver enzymes
Low Platelets
What is HELLP syndrome?
A combination of features that occur as a complication of pre-eclampsia and eclampsia
What are the risk factors for gestational diabetes?
Previous gestational diabetes
Previous macrosomic baby (>4.5kg)
BMI>30
Black Caribbean, Middle Eastern or South Asian ethnicity
Family history of diabetes (first degree relative)
What presenting features suggest gestational diabetes?
Large-for-date foetus
Polyhydramnios
Glucose on urine dipstick
What is the initial investigation of choice for gestational diabetes?
Oral glucose tolerance test (OGTT)
Performed in the morning after fasting
Patient then drinks 75g of glucose in solution
Normal glucose before = <5.6mmol/l
Normal glucose after 2 hours = <7.8mmol/l
(5-6-7-8)
What is the management of gestational diabetes?
Fasting glucose <7mmol/l = diet and exercise for 1-2 weeks, then metformin, then insulin
Fasting glucose >7mmol/l OR >6mmol/l with macrosomia = Start insulin +/- metformin
What is the cause of anaemia in pregnancy?
In pregnancy, the total blood volume increases
This means that the Hb concentration is decreased
What is the management of anaemia in pregnancy?
Iron replacement
B12 replacement –> IM hydroxocobalamin/oral cyanocobalamin
Folic acid
What are the risk factors for VTE in pregnancy?
Smoking
Parity >=3
Age>35
BMI>30
Reduced mobility
Multiple pregnancy
Pre-eclampsia
Immobility
Family history
IVF pregnancy
What VTE prophylaxis is given in pregnancy?
Low molecular weight heparin –> asap in very-high risk (4 or more risk factors), at 28 weeks in high risk (3 risk factors)
What is the presentation of VTE in pregnancy?
Unilateral calf or leg swelling
Dilated superficial veins
Tenderness to the calf
Oedema
Colour changes to the leg
Signs of PE –> SoB, chest pain, cough etc
Why is VTE risk increased in pregnancy?
Hyper-coagulable state
What is placenta praevia?
When the placenta lies over the internal cervical os
What is the definition of low-lying placenta?
When the placenta is within 20mm of the internal cervical os
What are the grades of placenta praevia?
Grade 1 (minor) = Placenta is in the lower uterus but not reaching the internal cervical os
Grade 2 (marginal) = Placenta is reaching, but not covering, the internal os
Grade 3 (partial) = Placenta is partially covering the internal os
Grade 4 (complete) = Placenta is completely covering the internal os
What are the risk factors for placenta praevia?
Previous C section
Previous placenta praevia
Older maternal age
Maternal smoking
Structural uterine abnormality (eg. fibroids)
IVF
How is a diagnosis of placenta praevia made?
20 week anomaly scan identifies the position of the placenta
Many women are asymptomatic
May present with antepartum haemorrhage
What is the management of placenta praevia?
Transvaginal US for monitoring
Corticosteroids given between 34 and 35+6 weeks to promote fetal lung maturation
Planned C section at 36-37 weeks
Emergency C-section if labour is premature or any bleeding
What is placenta accreta?
When the placenta implants deeper, through and past the endometrium, making it difficult to separate the placenta after delivery
What are the risk factors for placenta accreta?
Previous placenta accreta
Previous miscarriage
Previous C section
Multigravida
Increased maternal age
Low-lying placenta or placenta praevia
What is the management of placenta accreva?
Planned delivery between 35 and 36+6 weeks
Recommended hysterectomy
Uterine preserving surgery
Expectant management –> risks of bleeding and infection
What is vasa praevia?
Where fetal vessels (two umbilical arteries and one umbilical vein) are in the fetal membranes and travel across the internal cervical os, outside the protection of the placenta or umbilical cord
What are the risk factors for vasa praevia?
Low lying placenta
IVF
Multiple pregnancy
What is the management of vasa praevia?
Corticosteroids to mature the fetal lungs
Planned C-section at 34-36 weeks
Emergency C-section if antepartum haemorrhage occurs
What is placental abruption?
When the placenta comes away from the uterine wall during pregnancy
What are the risk factors for placental abruption?
Previous placental abruption
Pre-eclampsia
Trauma
Multiple pregnancy
Multigravida
Increased maternal age
Smoking
Cocaine/amphetamine use
What is the presentation of placental abruption?
Sudden onset, continuous, severe abdominal pain
Vaginal bleeding
Shock (hypotension and tachycardia)
Abnormalities on CTG showing fetal distress
Woody abdomen on palpation
What is the management for placental abruption?
Obstetric emergency
Steroids to mature fetal lungs
Emergency C-section if mother is unstable or fetus is distressed
What is the definition of a stillbirth?
The birth of a dead fetus after 24 weeks gestation
What is cord prolapse?
When the umbilical cord descends below the presenting part of the fetus into the vagina after rupture of the fetal membranes
Significant risk of compression causing fetal hypoxia
What is the management of a prolapsed cord?
Move patient onto all fours whilst preparing for emergency C-section
Push presenting part back into the uterus to prevent compression
Fill bladder to elevate presenting part
Emergency C-section
What are the degrees of perineal tears?
First degree = Superficial damage with no muscle involvement
Second degree = Injury to perineal muscle but not involving anal sphincter
Third degree = Injury to perineum involving the anal sphincter
Fourth degree = Injury to perineum involving the anal sphincter and rectal mucosa
What is the management of perineal tears?
First degree = Does not require repair
Second degree = Suturing on the ward
Third or fourth degree = Repair in theatre
What are the risk factors for perineal tears?
Primigravida
Large babies
Precipitant labour
Shoulder dystocia
Forceps delivery
What is the timeframe of a primary vs secondary postpartum haemorrhage?
Primary = within 24 hours
Secondary = 24 hours to 12 weeks
What volume of blood loss indicates postpartum haemorrhage?
> 500ml
What are the causes of postpartum haemorrhage?
Tone –> uterine atony (majority of cases)
Trauma –> eg perineal tear
Tissue –> retained placenta
Thrombin –> bleeding disorder
What are the risk factors for primary postpartum haemorrhage?
Previous PPH
Prolonged labour
Pre-eclampsia
Increased maternal age
Polyhydramnios
Emergency C-section
Placenta praevia/accreta
Macrosomia
What is the management of a postpartum haemorrhage?
Mechanical –> Rub the uterus to stimulate contractions, catheterisation
Medical –> IV oxytocin, IV or IM ergometrine, IM carboprost (unless asthmatic), misoprostol
Surgical –> Intrauterine balloon tamponade, ligation of uterine arteries etc
What are the most likely causes of secondary postpartum haemorrhage?
Retained products of conception
Infection
What is the management of chickenpox in a pregnant mother who is unsure if they have has chickenpox before?
Aciclovir
What screening tests are done for Down’s syndrome?
Combined test done 11-13+6 weeks:
Nuchal translucency –> Thickened in Down’s
Serum B-HCG –> Increased in Down’s
PAPP-A –> Decreased in Down’s
Triple test done at 14-20 weeks:
Beta-HCG –> Increased in Down’s
Alpha-fetoprotein (AFP) –> Lower in Down’s
Serum oestriol –> Lower in Down’s
Quadruple test done at 14-20 weeks:
Same as triple test
Also includes Inhibin-A –> Increased in Down’s
What is the first stage of labour?
From the onset of labour until the cervix is fully dilated at 10cm
Involves cervical dilation and effacement
Mucus plug falls out
What are the three phases of the first stage of labour?
Latent phase = 0-3cm dilation at 0.5cm per hour with irregular contractions
Active phase = 3-7cm dilation at 1cm per hour with regular contractions
Transition phase = 7-10cm dilation at 1cm per hour with strong, regular contractions
What is the second stage of labour?
From 10cm dilation to delivery of the baby
What is the third stage of labour?
From delivery of the baby to delivery of the placenta
What factors affect the success of the second stage of labour?
Power –> Strength of uterine contractions
Passenger –> Size (size of head at largest point), Attitude (posture eg. how the back is rounded), Lie (position of fetus relative to the mother), Presentation (part of fetus closest to cervix)
Passage –> Size and shape of the passageway, particularly the pelvis
What are the seven cardinal movements of labour?
Engagement
Descent
Flexion
Internal rotation
Extension
Restitution and external rotation
Expulsion
What gestation is classed as premature?
Before 37 weeks
What can be given prophylactically to prevent preterm labour?
Vaginal progesterone –> Decreases activity of myometrium and prevents cervical remodelling
What is the management of preterm prelabour rupture of membranes?
Prophylactic antibiotics (erythromycin) for 10 days or until labour is established
Induction of labour may be offered
What is the management of preterm labour with intact membranes?
Fetal monitoring
Tocolysis (medication to stop uterine contractions) with nifedipine (a CCB that suppresses labour)
Corticosteroids (promotes fetal lung maturation)
IV magnesium sulphate (protects baby’s brain)
What are the indications for induction of labour?
When patients go over due date
Prelabour rupture of membranes
Pre-eclampsia
Obstetric cholestasis
Existing diabetes
Intrauterine fetal death
What is the Bishop score?
Scoring system to determine whether or not to induce labour
Scored on a scale of 0-13
Score of 8 or more indicates a successful induction of labour
Score of less than 8 suggests cervical ripening is required
Five factors assessed:
Fetal station (0-3)
Cervical position (0-2)
Cervical dilation (0-3)
Cervical effacement (0-3)
Cervical consistency (0-2)
What are possible methods of induction of labour?
Membrane sweep
Vaginal prostaglandins
Cervical ripening balloon –> inserted into cervix and gently inflates, dilating the cervix
Artificial rupture of membranes with oxytocin (only if vaginal prostaglandins are contraindicated or have failed)
Oral mifepristone + misoprostol –> if intrauterine fetal death
What is a complication of induction of labour with vaginal prostaglandins?
Uterine hyperstimulation
What is the management of uterine hyperstimulation?
Removing the vaginal prostaglandins or stopping oxytocin infusion
Tocolysis with terbutaline
What does cardiotocography measure?
Fetal heart rate –> sensor placed above fetal heart
Contractions of the uterus –> sensor placed near the fundus of the uterus
What are the indications for continuous CTG monitoring?
Sepsis
Maternal tachycardia
Significant meconium
Pre-eclampsia
Fresh antepartum haemorrhage
Delay in labour
Use of oxytocin
Disproportionate maternal pain
What are the 5 features to look for on a CTG?
Contractions = Number per 10 minutes
Baseline fetal heart rate
Variability = How the fetal heart rate varies about the baseline
Accelerations of fetal HR –> generally good sign
Decelerations of fetal HR –> more concerning if after uterine contractions or for prolonged time
What is the rule of 3s for fetal bradycardia?
3 minutes = call for help
6 minutes = move to theatre
9 minutes = prepare for delivery
12 minutes = deliver the baby (by 15 minutes)
What is oxytocin used for in labour?
Induction
Progression
Improve frequency and strength of contractions
Prevent of treat PPH
What is ergometrine used for in labour?
Stimulates smooth muscle contraction
Used for delivery of placenta
Reduce PPH
Only used postpartum
What are prostaglandins used for in pregnancy?
Have hormonal effects locally
Prostaglandin E2 used in induction of labour
What is recorded on a partogram?
Cervical dilation
Descent of fetal head
Maternal pulse, BP, temp and urine output
Fetal HR
Frequency of contractions
Membrane status
Any drugs or fluids being given
What pain relief is used in labour?
Simple analgesia –> Paracetamol, codeine. NSAIDs are avoided
Gas and Air (Entonox)
IM pethidine or diamorphine
Epidural
What is shoulder dystocia?
When the anterior shoulder of the baby becomes stuck behind the pubic symphysis
What is the presentation of shoulder dystocia?
Difficulty delivering the face and head
Face remains downwards after delivery of the head
Turtle-neck sign = Where the head is delivered but retracts back onto the vagina
What is the management of shoulder dystocia?
Obstetric emergency
Episiotomy
McRoberts manoeuvre = Bringing knees up to abdomen to lift the pubic symphysis out of the way
Pressure to anterior shoulder by pressing on the suprapubic abdomen
What are the indications for an instrumental delivery?
Failure to progress
Fetal distress
Maternal exhaustion
Control the head in various fetal positions
Increased risk if epidural in place as less pushing power
What are the indications for an elective C-section?
Previous C-section
Symptomatic after previous significant perineal tear
Placenta praevia
Vase praevia
Breech presentation
Multiple pregnancy
Uncontrolled HIV
Cervical cancer
What are the different categories of C-section?
Category 1 = Immediate threat to life of mother/baby –> Delivery in 30 minutes
Category 2 = Not imminent threat to life but required urgently due to compromise of mother or baby –> Delivery in 75 minutes
Category 3 = Delivery in required, but mother and baby are stable
Category 4 = Elective
What are the risk factors for a uterine rupture?
Previous C-section
Previous uterine surgery
Increased BMI
High parity
Increased age
Induction of labour
What is the presentation of a uterine rupture?
Abdominal pain
Vaginal bleeding
Ceasing of uterine contractions
Hypotension
Tachycardia
Collapse
What is the management of uterine rupture?
Emergency C-section
Repair or remove the uterus
What are the baby blues?
A mental illness affecting around 50% of mothers in the first week or so after birth
What are the precipitating factors for baby blues?
Significant hormonal changes
Recovery from birth
Fatigue and sleep deprivation
Responsibility and pressure
Changes in environment
What are the symptoms of baby blues?
Mood swings
Low mood
Anxiety
Irritability
Tearfulness
What is puerperal psychosis?
Rare but severe illness starting 2-3 weeks after delivery
What are the symptoms of puerperal psychosis?
Delusions
Hallucinations
Depression
Mania
Confusion
Thought disorder
What is an amniotic fluid embolism?
When fetal cells/amniotic fluid enter the mother’s bloodstream and stimulate a reaction
What are the presentations of an amniotic fluid embolism?
Occur in labour or in the immediate post-partum
Chills/shivering/sweating
Anxiety
Coughing
Cyanosis
Hypotension
Tachycardia
Bronchospasms
Myocardial infarction
What is the management of an amniotic fluid embolism?
ICU
Supportive
Monitor BP and HR
What is the presentation of obstetric cholestasis?
Itching –> particularly palms and soles of feet
Fatigue
Dark urine
Pale, greasy stools
Jaundice
NO RASH
What is gastroschisis?
Congenital defect in the anterior abdominal wall lateral to the umbilical cord, allowing the intestines and other abdominal organs to exit the body
What is the management of gastroschisis?
Vaginal delivery may be attempted
Newborns should go to theatre within 4 hours of delivery
What is exomphalos/omphalocoele?
Where the abdominal contents protrude through the anterior abdominal wall but are covered in amniotic sac formed by the amniotic membrane and peritoneum
What is the management of exomphalos?
C-section to reduce risk of sac rupturing
Repair often difficult due to high intra-abdominal pressure so wait until infant has grown and contents can be put back inside and damage repaired
At what gestation should a booking visit be done?
8-12 weeks
At what gestation should the early scan to confirm dates be done?
10-13+6 weeks
At what gestation can Down’s syndrome screening, including nuchal scan, be done?
11-13+6 weeks
At what week is an anomaly scan done?
18-20+6 weeks
At what gestation is external cephalic version offered if indicated?
36 weeks
What physiological changes to blood pressure happen in pregnancy?
Falls in the first trimester until 20-24 weeks and the increases to the pre-pregnancy levels by term
What are the 2 phases of the menstrual cycle?
Follicular phase (first 14 days)
Luteal phase (last 14 days)
What is the role of FSH at the start of the menstrual cycle?
Stimulate development of the secondary follicles
What is the role of granulosa cells in the follicular phase of the menstrual cycle?
Surrounds the follicles
Secretes oestradiol (naturally occurring oestrogen)
What is the effect of oestradiol on the pituitary gland?
Negative feedback
Reduces the levels of LH and FSH
What is the effect of rising oestrogen on the cervix?
Causes the cervical mucus to be more permeable, allowing sperm to penetrate the cervix
Which hormone causes the follicle to release the ovum?
LH
At what date does ovulation occur?
14 days before the end of the cycle
(Day 14 of 28-day cycle, Day 16 of 30-day cycle etc)
What happens to the follicle after releasing the ovum?
Collapses and becomes the corpus luteum, which secretes high levels of progesterone
What is the role of progesterone in the luteal phase?
Maintain the endometrial lining and thickens the cervical mucus, making it no longer penetrable
What maintains the corpus luteum after fertilisation?
The syncytiotrophoblast of the embryo secretes HCG, which maintains the corpus luteum and continues the secretion of progesterone
What happens to the corpus luteum if there is no fertilisation?
It degenerates and stops producing oestrogen and progesterone
This causes the endometrium to break down and menstruation to occur
On what day of the menstrual cycle does menstruation occur?
Day 1
What is the effect of no fertilisation on LH and FSH?
No fertilisation causes the corpus luteum to break down, stopping the secretion of oestrogen and progesterone
This stops the negative feedback of oestrogen and progesterone on the hypothalamus and pituitary gland, allowing FSH and LH to begin to rise
The cycle restarts
What are the physiological cardiovascular changes in pregnancy?
Increased blood volume
Increased plasma volume
Increased cardiac output –> increased stroke volume and heart rate
Decreased peripheral vascular resistance
Decreased blood pressure in early and middle trimesters, returning to normal by term
Varicose veins
Peripheral vasodilation (flushing and hot sweats)
What are the physiological respiratory changes in pregnancy?
Tidal volume and respiratory rate increase in later pregnancy to meet increased oxygen demand
What are the physiological renal changes in pregnancy?
Increased renal blood flow
Increased GFR
Increased aldosterone
Increased protein excretion
What are the physiological haematology changes in pregnancy?
Increased RBC production
Higher iron, folate and B12 requirements
Lower concentration of RBC due to higher plasma volume increase –> anaemia
What are the 3 stages of postpartum thyroiditis?
Thyrotoxicosis
Hypothyroidism
Normal thyroid function, but high recurrence rate in future pregnancies
What is the management of the thyrotoxicosis stage of postpartum thyroiditis?
Propranolol until symptoms resolve in around 1 year
Not usually treated with anti-thyroid drugs
What is the management of the hypothyroid phase of postpartum thyroiditis?
Thyroxine
What is oligohydramnios?
Deficiency of amniotic fluid in pregnancy
What are the causes of oligohydramnios?
Premature rupture of membranes
Fetal renal problems/agenesis
Intrauterine growth restriction
Post-term gestation
Pre-eclampsia
How can fetal growth be assessed?
Measure length of femur on US
Measure fetal abdominal circumference using US
Measure size of uterus on abdominal examination
Palpate the fetal head on examination
Measure length of femur on US
What antibiotics are safe to use at any stage of pregnancy?
Cephalosporins
What are risk factors for intrauterine growth restriction?
Maternal age under 16 or over 35
Low BMI
>75kg
Interpregnancy interval of less than 6 months or over 120 months
Trisomy 18
Pre-eclampsia
