Obstetrics Flashcards
1
Q
What are the main functions of the placenta?
A
Nutrition Respiratoin Immunity Excretion Endocrine - oestrogen helps soften tissues and prepares mother's breasts // progesterone maintains pregnancy by keeping uterine muscles relaxed
2
Q
what are the 3 stages of labour?
A
FIRST STAGE = Onset (true contractions) until 10cm dilation
a. Latent 0-3cm - 0.5cm/hr, irregular contractions
b. Active 3-7cm - 1cm/hr regular contractions
c. Transition 7-10cm - strong regular contractions
SECOND STAGE = 10cm dilation to delivery of baby. Success depends on Power, Passenger, Passage
THIRD STAGE = Delivery of baby to delivery of placenta
3
Q
What are the 2 broad methods of managing the third stage of labour?
A
Physiological management - placenta delivered by maternal effort
Active management - IM oxytocin and careful traction to cord. This shortens 3rd stage and reduces risk of bleeding.
If haemorrhage or >1 hour delay, give active management.
4
Q
What are the main movements of labour?
A
Engagement Descent Flexion Internal rotation Extension Restitution + external rotation Expulsion
5
Q
What are Braxton-Hicks contractions?
A
Occasional irregular uterine contractions in the 2nd and 3rd trimester.
Advise reduce stress and keep hydrated.
6
Q
What hormones from the Anterior pituitary have a physiological effect during pregnancy?
A
- Raised ACTH –> raised steroid hormones = improves automimmue conditions but more susceptible too infection and DM
- Raised prolactin - reduced FH and LSH
- Increased skin pigmentation
7
Q
what happens to the following hormone levels during pregnancy?
TSH
HCG
Progesterone
Oestrogen
A
TSH - normal but T3/4 raised
HCG - doubles every 48 hours, plateaus at 8-12 weeks, then falls
Progesterone and oestrogen both rise throughout pregnancy
8
Q
What type of anaemia is common in pregnancy?
A
Iron deficiency anaemia
Increased RBCs but blood volume increases even more
9
Q
What might pruritis be a sign of in pregnancy?
A
May be normal but may be due to obstetric cholestasis
10
Q
What normal blood changes would you see in pregnancy?
A
Raised WBC Low platelets (VTE risk) Raised ESR Raised D-dimer Raised ALP - up to 4x normal, due too excretion by placenta
11
Q
What is premature rupture of membranes?
What is pre-term premature rupture of membranes?
A
occurs at least 1 hour prior to onset of labour, at ≥37 weeks - minimal risk of harm
Pre-term = <37 weeks, occurs in 2% of pregnancies and is associated with complications
12
Q
What are the risk factors for PROM?
A
Smoking Previous PROM or preterm delivery Multiple pregnancy Cervical insufficiency Vaginal bleeding during pregnancy Invasive procedures eg. amniocentesis Polyhydramnios
13
Q
What investigations would you do in a PROM/PPROM?
A
Speculum exam = pooling
IGFBP-1 or PAMG-1 in vaginal fluid
High vaginal swab to look for signs of infection (group B streptococcus –> give clinamycin/penicillin)
14
Q
How would you manage a PROM?
A
Induction of labour from week 34
Before this aim to prolong gestation - give steroids
Give prophylactic abx to prevent chorioamnionitis (erythromycin for 10 days or until labour)
15
Q
What is the definition of a miscarriage?
A
Loss of pregnancy <24 weeks gestation
16
Q
What are the risk factors fir miscarriage?
A
Smoking / alcohol increased maternal age previous miscarriage chromosomal abnormalities Antiphospholipid syndrome uterine abnormalities or previous surgery
17
Q
How is a miscarriage diagnosed on TVUSS?
A
- Fetal heartbeat
- Crown rump length - heartbeat should be seen at >7mm. If no heartbeat at <7mm scan again in at least 1 week before diagnosing a missed pregnancy.
- look for fetal pole. If no fetus seen measure mean sac diameter:
>25mm and no fetus = anembryonic miscarriage
<25mm and no fetus = re-scan in 10-14 days
18
Q
What are the treatment options for a miscarriage?
A
- Conservative
- Medical
- Surgical
Regardless of tx type = if pt is Rh- and >12 weeks then give anti-d prophylaxis
19
Q
What is medical management of miscarriage?
A
Vaginal misoprostol (prostaglandin analogue) - stimulates cervical ripening and contractions
Pregnancy test 3 weeks later
20
Q
What is surgical management of miscarriage?
A
Manual vacuum aspiration under local anaesthetic if <12 weeks
Electrical evacuation of RPOC under GA if >12 weeks
21
Q
What are the indications for surgical management of miscarriage?
A
haemodynamically unstable
infected tissue
gestational trophoblastic disease
22
Q
What are the different types / stages of miscarriage?
A
Threatened = bleeding but cervix closed and fetus alive
Inevitable = bleeding and cervix open
Missed - no fetal pulse, ongoing discharge, may be asymptomatic
Incomplete - RPOC
Complete - symptoms settled
Septic
23
Q
What are the risk factors for gestational diabetes?
A
BMI >30 previous GD Asian 1st degree relative with DM PCOS previous macrosomic baby
24
Q
What are the fetal complications of gestational diabetes?
A
Macrosomia
Organomegaly
Erythropoiesis
polyhydramnios
Increased rates of pre-term delivery
Increased risk of hypoglycaemia after birth
Increased risk of transient tachypnoea of the newborn
25
How is gestational diabetes diagnosed?
FG >5.6 or 2 hour postprandial glucose >7.8
26
What is the management for gestational diabetes?
Lifestyle advice
Metformin
Glibenclamide if metformin not tolerated
insulin
27
What is pre-eclampsia?
| What is the triad?
New HTN in pregnancy with end-organ dysfunction. It occurs due to abnormal formation of the spiral arteries after 20 weeks.
1. Hypertension
2. Proteinuria
3. Oedema
If no proteinuria = pregnancy induced HTN
If seizures = eclampsia
28
What are the high risk and moderate risk RFs for pre-eclampsia?
```
Moderate
>40yrs
BMI >35
Multiple pregnancy
First pregnancy
FHx of pre-eclampsia
```
```
High
pre-existing HTN
previous HTN in pregnancy
Autoimmune conditions
DM / CKD
```
29
What are the SYMPTOMS of pre-eclampsia (other than the triad)
```
Headache
Visual symptoms
Epigastric pain (liver swelling)
Oedema
Brisk reflexes
Nausea and vomiting
```
30
How is pre-eclampsia diagnosed?
BP >140/90 plus any of:
- Proteinuria
- Organ dysfunction
- Placental dysfunction (growth restriction or abnormal doppler)
Also - placental growth factor will be LOW
31
What is the management for pre-eclampsia?
Routine monitoring - BP, symptoms and dipstick. serial growth scans
Medical:
Aspirin from 12 weeks if 1 high risk RF or >2 moderate
1. Labetolol
2. Nifedipine
During labour: IV MgSO4 to prevent seizures, fluid restriction
32
What is HELLP syndrome?
A complication of pre-eclampsia
Haemolysis
Elevated Liver enzymes
Low platelets
33
What is placenta praevia?
Placenta is attached in the lower portion of the uterus (lower than presenting part of fetus)
34
What is the difference between a low lying placenta and placenta praevia?
Low-lying = placenta is within 20mm of internal cervical os
Praevia = placenta over internal cervical os
35
What are the possible complications of placenta praevia?
Antepartum haemorrhage
Emergency C section
Maternal anaemia / transfusion
Pre-term birth/ low birth weight
36
What are the grades of placenta praevia?
Minor/ I = placenta not reaching os
Marginal / II = reaching but not covering
Partial / III = partially covering
Complete
37
What are the risk factors for placenta praevia and accreta?
```
Previous C section or placenta praevia/accreta
Older maternal age
IVF
smoking
structural - fibroids
```
38
How does placenta praevia or placenta accreta present?
Asymptomatic or painless bleeding (antepartum haemorrhage)
Seen at 20 week scan
Placenta accreta may present at birth with PPH
39
How is gestational HTN managed?
Aim <135/85
Admit if >160/110
Dipstick weekly and monitor bloods
Serial growth scans
40
What is the management of placenta praevia
TVUSS at 32 + 36 weeks
Corticosteroids at 34-36weeks to mature lungs
Planned C section at 36-37 weeks
41
What is placenta accreta?
Placenta implants too deep through + past the endometrium so it is difficult to separate the placenta post delivery
This causes an increased risk of PPH
42
What are the 3 severities of placenta accreta?
Superficial placenta accreta = myometrium surface
Placenta increta = deep myometrium
Placenta percreta = past myo + peri-metrium
43
What is the management of placenta accreta?
MRI to assess depth
Corticosteroids + delivery planned for 35-37 weeks
Delivery options:
- hysterectomy = recommended
- uterus preserving
- expectant (leave placenta in place to be reabsorbed over time -- risky!!)
44
What are the risk factors for placental abruption?
```
Previous abruption
Domestic violence / trauma
Bleeding early in pregnancy
Fetal growth restriction
Pre-eclampsia
Multigravida, age, smoking
```
45
What is the presentation of placental abruption?
What is a concealed abruption?
How is it diagnosed?
Sudden onset CONTINUOUS + SEVERE abdominal pain
Antepartum haemorrhage - if no bleeding consider concealed?
Shock
Fetal distress on CTG
On examination = WOODY abdomen
Concealed abruption = cervical os remains closed so bleeding remains in the uterus -- do not underestimate severity
CLINICAL DIAGNOSIS
46
How is placental abruption managed?
Steroids
C-section
Resuscitation
47
What is the definition of PPH?
500ml loss after vaginial delivery
1000ml after C section
Primary <24 hours
Secondary 24 hours - 12 weeks
48
What are the 4 main causes of PPH?
Tone (most common - uterine atony)
Trauma (perineal tear)
Thrombin (bleeding disorder)
Tissue (retained placenta)
49
What are the risk factors for PPH?
```
Previous PPH
Prolonged 3rd stage
Multiple pregnancy
Large baby
Failure to progress too 2nd stage
Pre-eclampsia
Perineal tear
Placenta accreta
```
50
What measures can be taken to prevent PPH?
give birth with empty bladder
Active management of 3rd stage - IM oxytocin
IV tranexamic acid in 3rd stage of high risk C sections
51
What is the management of PPH?
```
ABCDE
Lie woman flat and keep warm
Communication
2x large cannulas
crossmatch 4 units blood
warmed IV fluid + blood resuscitation
Oxygen
Fresh frozen plasma if clotting abnormalities
```
52
How is bleeding stopped in a PPH?
Mechanical - rubbing uterus, catheterisation
Medical - oxytocin, tranexamic acid, ergometrine, PG analogues
Surgical - IU balloon tamponade, uuterine artery ligation, hysterectomy
53
What is a complete and incomplete uterine rupture?
Complication of labour
Complete = contents of uterus are released into uterine cavity
Incomplete = myometrium ruptures but perimetrium stays intact
54
What is the main risk factor for uterine rupture?
Previous C section (scar = weakness)
Other:
- previous surgery
- high BMI
- age
- high parity
- induction of labour
55
What is the clinical presentation of uterine rupture?
Acutely unwell mother and abnormal CTG
- abdo pain
- vaginal bleeding
- uterine contractions stop
- hypotension
- tachycardia
- collapse
56
What is the management of uterine rupture?
Resuscitation + transfusion
Emergency C section
?Hysterectomy
57
What is umbilical cord prolapse?
How is it diagnosed?
Cord descends below presenting part of fetus, through cervix and into vagina
Risk of fetal hypoxia as cord is compressed by presenting part. The main risk factor is an abnormal lie after 37 weeks
Dx - suspect when fetal distress on CTG, confirmed with speculum exam
58
What is the management of cord prolapse?
Emergency C section
Keep cord warm and wet (minimal handling)
Push presenting part back up if causing compression
Lie woman in left lateral position with knees up - draws fetus away from pelvis
59
What is vasa praevia?
Rare but serious labour complication
Fetal umbilical cord vessels run across or very close to internal cervical os unprotected by the umbilical cord or the placenta
Therefore there is a high risk of the exposed vessels bleeding when the membranes rupture during labour, causing haemorrhage and fetal death
60
What are the main RFs for vasa praevia?
How is vasa praevia diagnosed?
Multiple pregnancy
IVF
Low lying placenta
Sx = antepartum haemorrhage?
During labour:
Pulsating vessels seen in the membranes through the dilated cervix
Fetal distress and dark red bleeding following rupture of membranes
61
What is the management of vasa praevia?
Asymptomatic - corticosteroids from 32 weeks and elective C sectiono 34-36 weeks
When antepartum haemorrhage occurs = emergency C section
Placenta examined for vasa praevia in any still birth or unexplained fetal compromise
62
What is the definition of:
Small for gestational age?
Low birth weight?
SGA = Birth weight <10th centile for gestational age. Severe if <3rd
LBW = <2500g birth weight
63
What are the main causes of SGA / fetal growth restriction?
1. Consitutionally small = follows centiles, no pathology
2. Placenta mediated = initially normal then slows (placental insufficiency)
3. Non-placenta mediated = fetal factors (chromosomal abnormalities, fetal infection)
64
All women should be assessed for SGA risk factors and at 20 weeks. What are the minor risk factors for SGA?
```
Age ≥35
Light smoker
Nulliparity
BMI <20 or 25-35
IVF
Previous pre-eclampsia
Pregnancy interval <6 months or ≥60 months
```
65
What are the major risk factors for SGA?
```
Age ≥40
Heavy smoker
Previous SGA baby
Maternal/paternal SGA
Pervious still birth]Cocaine
Vigorous exercise
Heavy bleeding
Low pregnancy-associated Plasma protein
```
66
How is a diagnosis of SGA made?
Ratio of head circumference to abdo circumference:
Symmetrically small - likely constitutional
Asymmetrically small - likely placental
67
How is an SGA pregnancy managed?
```
Modify risk factors
Aspirin if high risk of pre-eclampsia
Surveillance:
- uterine artery doppler
- serial growth scans
- amniotic fluid vol
```
68
What are the indications for C section or induction in an SGA pregnancy?
Induction:
by 37 weeks if abnormal UAD
At 37 weeks if normal UAD
C section
<37 weeks and absent/ reverse end-diastolic flow on doppler
69
What are the neonatal complications of SGA?
```
Birth asphyxia
Meconium aspiration
Hypothermia
Hypo/hyperglycaemia
Polycyhthaemia
Retinopathy of prematurity
Pulmoonary haemorrhage]Necrotising enterocolitis
```
70
What are the long term complications of SGA?
```
Cerebral palsy
T2DM
Obesity
Hypertension
Precocious puberty
Behavioural problems
Cncer
Alzheimers
Dpression
```
71
2 causes of painless antepartum haemorrhage?
```
Placenta praevia (before ROM)
Vasa praevia (after ROM)
```
72
2 causes of painful antepartum haemorrhage?
```
Placental abruption (hypertonic contractions - woody abdomen)
Uterine rupture (contractions stop suddenly)
```
73
When does baby-blues, postnatal depression and postpartum psychosis occur?
Baby blues = first week
Postnatal depression = 3 months
Psychosis = 2-3 weeks
74
What would a micro/normocytic anaemia in pregnancy suggest?
What about macrocytic?
micro/normocytic = iron deficiency
Macrocytic = folate deficiency
75
What is the diagnostic test for DVT?
Compression duplex USS (if negative USS but clinical suspicion remains, repeat test and treat)
76
What are the diagnostic tests for PE?
ECG, CXR
CTPA and V/Q scan = definitive
77
How would you treat a suspected VTE (DVT or PE) in pregnancy?
LMWH starting immediately
Confirmed VTE - continue anticoagulation until 6-12 weeks postpartum. Omit LMWH dose 24 hours before induction or C section.
If VTE occurs at term - give IV unfractionated heparin as can be stopped 6 hours before induction or C section.
78
What are the general guidelines for VTE prophylaxis in pregnancy and postpartum?
What blood thinner must NOT be given in pregnancy?
- LMWH from 28 weeks if previous VTE from major surgery
- LMWH throughout pregnancy if previous VTE for any other reason
- HIGH DOSE LMWH if antithrombin deficiency or antiphospholipid syndrome
- 10 day course LMWH for any women who has a C section
DO NOT GIVE WARFARIN AS TERATOGENIC
79
What are the 3 antibodies looked for in blood tests for antiphospholipid syndrome?
Anticardiolipin
Lupus anticoagulant
Anti-B2-glycoprotein-1
Note - healthy people may test positive for these Abs
80
What are the clinical criteria for a diagnosis of antiphospholipid syndrome?
What other symptoms may be present?
venous thrombosis
recurrent pregnancy loss
Sx - DVT, PE, valve disease (mitral), kidney problems, headaches, seizures, livedo reticularis (hexagonal rash)
81
What are the diagnostic criteria for hyperemesis gravidarum?
>5% body weight loss compared with before pregnancy
dehydration
electrolyte imbalance
82
What are the recommended antiemetics for treating hyperemesis gravidarum?
1. Prochlorperazine
2. Cyclizine
3. Ondansetron
4. Metoclopramide
83
What are the antibiotic options for UTI in pregnancy?
Trimethoprim - avoid in 1st trimester (neural tube defects)
Nitrofurantoin - avoid in 3rd trimester (neonatal haemolysis)
Cefalexin - no risks
Amoxicillin
84
What hormone tests can be performed in infertility?
Serum LH and FSH on days 2-5 (high LH = PCOS, high FSH = poor ovarian reserve)
Anti-Mullerian hormone = best indication, high = good ovarian reserve
TFTs if indicated
Serum progesterone on 21 = high means ovulation has occured
Prolactin if Sx of amenorrhoea or galactorrhea
85
What initial investigations would be appropriate for a couple struggling to conceive?
```
BMI check - ?PCOS or underweight?
Chlamydia screen
Semen analysis
Rubella immunity
Female hormone status
```
86
What lifestyle advice should be given to couples trying to conceive?
```
400mcg folic acid daily
Healthy BMI
Sex every 2-3 days
avoid smoking and alcohol
reduce stress
```
87
What is the management where anovulation is the cause of infertility?
Clomifene - stimulates ovulation by eradicating negative feedback of oestrogen --> more GnRH, LH and FSH
Gonadotropins if resistant to clomifene
Weight loss or ovarian drilling in PCOS
88
What imaging tests can be performed in female infertility?
USS pelvis - PCOS or structural abnormalities
Hysterosalpingogram - patency of fallopian tubes
Laparoscopy + dye test - patency of fallopian tubes + presence of adhesions/ endometriosis
89
What are the main causes of macrosomia?
```
Consitutional
Maternal diabetes
Previous macrosomia
Materal obesity or rapid weight gain
Overdue
Male baby
```
90
What are the main risks associated with macrosomia?
```
Maternal risk:
Shoulder dystocia
Failure to progress
Perineal tears
Instrumental delivery
PPH
Uterine rupture (rare)
```
```
Baby risk:
Birth injury
Neonatal hypoglycaemia
Obesity in childhood
T2DM in adulthood
```
91
What are the investigations for a large for gestational age baby?
USS to exclude polyhydramnios and estimate the fetal weight
| OGTT - gestational diabetes?
92
What are the common causes of polyhydramnios?
```
Idiopathic
Chromosomal abnormalities
Swallowing problems - oesophageal atresia
Duodenal atresia - double bubble on USS
Fetal hydrops
Twin to twin transfusion syndrome
increased lung secretions
Gestational diabetes
Viral infections
```
93
What is the management for polyhydramnios?
Usually no Tx
Aminoreduction if woman has severe symptoms (associated infection and placental abruption)
Indomethacin - reduce water retention so less fetal urine. Not used beyond 32 weeks.
In idiopathic polyhydramnios the baby must be assessed by a paediatrician before first feed.
94
What are the main causes of oligohydramnios?
```
PPROM
Renal agenesis (Potter's)
Obstructive uropathy
Genetic / chromosonal abnormalities
placental insufficiency
```
95
What is the definition of prematurity?
<37 weeks
32-37 moderate to late preterm
28-32 very preterm
<28 weeks extreme preterm
<23 weeks = non viable
96
What are the prophylaxis options for preventing preterm labour?
Vaginal progesterone - offered to women with cervical length <25mm on USS at 16-24 weeks
Cervical cerclage - stitch in cervix to keep it close, offered to women with cervical length <25mm with previous premature birth or cervical trauma (stitch removed in labour)
Rescue cervical cerclage - between 16-27+6 weeks when there is cervical dilatation without ROM
97
What is the presentation of preterm labour with intact membranes?
Regular painful contraction and cervical dilatation without rupture of amniotic sac
98
What are the management options for preterm labour?
- Fetal monitoring
- Tocolysis - nifedipine
- Maternal corticosteroids
- IV MgSO4 - protect fetal brain
- Delayed cord clamping - increases circulating blood volume
99
What is the pathophysiology of haemolytic disease of the newborn?
Rh -ve woman has first pregnancy with a Rh +ve baby -- fetal blood passes into maternal blood (sensitisation) causing Anti-D to be produced.
During her second pregnancy these Anti-D antibodies cross the placenta and cause haemolytic anaemia, raised bilirubin and jaundice in the fetus.
100
What is the management of a Rh negative woman in pregnancy?
What is Kleinhauer test?
prevention of sensitisation with IM Anti-D
Routine anti-D
- 28 weeks
- Birth if baby is found to be Rh +ve
Within 72 hours of sensitisation:
- Antepartum haemorrhage
- Abdominal trauma
- Amniocentesis procedures
Kleunhauer test - checks how much fetal blood mixed with maternal blood / if more Anti D is needed
