Obstetrics Flashcards
Contents: - Pregnancy and prenatal care - Pregnancy-associated disorders - Labour, delivery, and associated disorders - Puerperium
Pregnancy:
Definition of gravidity?
The number of times a woman has been pregnant, regardless of pregnancy outcome:
- Nulligravidity: no history of pregnancy
- Primigravidity: history of one pregnancy
- Multigravidity: history of two or more pregnancies
Pregnancy:
Definition of parity?
Refers to pregnancies that have resulted in delivery beyond 24 weeks gestation.
Pregnancy:
Normal duration of pregnancy?
What is termed pre-/post-term birth?
Normal = 40 weeks
- Pre-term = live birth before 37 weeks pregnancy
- Post-term = live birth after 42 weeks pregnancy
Pregnancy:
What are the dates of the trimesters?
First trimester = weeks 1 - 13
Second trimester = weeks 14 - 26
Third trimester = weeks 27 - 40
Pregnancy:
How is pregnancy tested for?
β-hCG
- Urine test (e.g. home test) - can be detected 14 days after fertilisation
- Serum test - higher sensitivity, detectable earlier (6 - 9 days)
Pregnancy:
Where is β-hCG made?
Placental syncytiotrophoblast
Pregnancy:
What does β-hCG do?
Maintains corpus luteum for the first 8-10 weeks of pregnancy
Pregnancy:
Causes of abnormally low β-hCG?
Maternal - Ectopic pregnancy - Abortion/miscarriage Fetal - Edwards syndrome (trisomy 18) - Patau syndrome (trisomy 13)
Pregnancy:
Causes of abnormally high β-hCG?
Maternal - β-hCG secreting tumours (e.g. hydatidiform mole/choriocarcinoma) - Multiple pregnancy Fetal - Down syndrome
Pregnancy:
When is the foetal heartbeat usually detectable on ultrasound?
10 - 12 weeks gestation
Pregnancy:
How to calculate gestational age and estimate the date of delivery?
Naegele rule: - First day of LMP + 7 days + 9 months - Can be inaccurate Ultrasound - More accurate - Measurement of the crown-rump length in the first trimester
Pregnancy:
How is fetal growth monitored during pregnancy?
Ultrasonography
- Fetal femoral length/abdominal circumference
Symphysis fundal height
- Top of uterus to top of pubic symphysis
- Growth is ≅ 1cm/week after 20 weeks
Pregnancy:
Cardiovascular changes?
↑ Cardiac output by 40%
↑ Heart rate
↓ Mean arterial pressure
↑ Plasma volume > ↑ RBC → ↓ Haematocrit
Pregnancy:
Respiratory changes?
↑ Oxygen consumption (around 20%)
↑ Intra-abdominal pressure causes ↓ Total lung capacity & dyspnoea
↑ Tidal volume
Progesterone stimulates respiratory centres → hyperventilation → chronic respiratory alkalosis (with full metabolic compensation)
Pregnancy:
Renal changes?
↑ Renal plasma flow → ↑GFR → ↓urea & creatinine
↑ Aldosterone → ↑ plasma volume and hypernatraemia
Pregnancy:
Haematological changes?
- Dilutional anaemia
- Hypercoagulability (↑clotting factors and ↓protein S)
Pregnancy:
Skin changes?
- Spider angioma
- Palmar erythema
- Striae gravidarum
- Hyperpigmentation (chloasma, linea nigra)
Pregnancy:
Risk factors for complicated pregnancy?
(Name a few, there are loads)
Family history of complex pregnancies
Personal history:
- Advanced age (>35)
- First pregnancy
- Multiple pregnancies
- Extreme multiparty (>5 births)
- Comorbidities (e.g. DM, anti-phospholipid s., HTN etc.)
- Social/environmental factors (e.g. drug use)
- Gynae. history (e.g. fibroids, past uterine surgery)
- Prior complicated pregnancy (e.g. prematurity, c-section, placental abruption, >2 miscarriages etc.)
- Complications that arise during pregnancy
Pregnancy:
Fetal causes of oligohydramnios?
- Urethral obstruction
- (Bilateral) renal agenesis
- Autosomal recessive polycystic kidney disease
- Aneuploidy (e.g. trisomy 18 - Edwards syndrome)
- Intrauterine infections
- Twin-to-twin transfusion syndrome (in donor twin)
Pregnancy:
Maternal causes of oligohydramnios?
- Late/post-term pregnancy (>42 weeks)
- Premature rupture of membranes
- Pre-eclampsia & placental insufficiency
- Maternal use of ACE-i or NSAIDs
Pregnancy:
Diagnosis of oligohydramnios?
Ultrasound scan to determine amniotic fluid volume and assess for fetal anomalies
Pregnancy:
Management of oligohydramnios?
- Treat underlying cause if applicable
- Delivery advised if close to term
Pregnancy:
Complications of oligohydramnios?
- IUGR
- Birth complications (e.g. umbilical cord compression)
Pregnancy:
Fetal causes of polyhydramnios?
- Usually idiopathic (70%)*
- GI malformations → reduced swallowing of amniotic fluid
- Anencephaly (same pathophys. as GI malformations)
- Twin-to-twin transfusion syndrome (in recipient twin)
Pregnancy:
Maternal causes of polyhydramnios?
- Usually idiopathic (70%)*
- Diabetes mellitus (DM)
- Rh incompatibility
Pregnancy:
Diagnosis of polyhydramnios?
Examination:
- SFH large for gestational age
Ultrasound:
- Measures volume of amniotic fluid
Pregnancy:
Management of polyhydramnios?
Medical - NSAIDs (reduce fetal GFR → less fluid produced)
Minimally invasive - amnioreduction (drainage)
Pregnancy:
Complications of polyhydramnios?
- Fetal malrotation/unstable lie
- Umbilical cord prolapse
- Premature birth
- Premature ROM
Multiple pregnancy:
Risk factors for multiple pregnancy?
- Advanced maternal age (≥35 years)
- Previous multiple pregnancy
- Use of assisted reproduction
- Maternal family history
Multiple pregnancy:
Classification of twins?
Monozygotic - Identical - 1/3 of twin pregnancies - 1 egg → 2 embryos Dizygotic - Non-identical - 2/3 of twin pregnancies - 2 eggs
Multiple pregnancy:
Types of monozygotic twin pregnancies?
- Dichorionic-diamniotic (both fetuses have separate sac and placenta)
- Monochorionic-diamniotic (one placenta and two sacs; risk of TTTS)
- Monochorionic-monoamniotic (twins share a single placenta and sac; risk of being conjoined)
Multiple pregnancy:
Complications of multiple pregnancy?
Almost all complications are the same, just more likely
Maternal: preterm birth, hyperemesis gravidarum, gestational diabetes, pre-eclampsia etc.
Fetal: twin-to-twin transfusion syndrome, increased neonatal morbidity & mortality
Multiple pregnancy:
Management of multiple pregnancy?
Prenatal care:
- More frequent antenatal care visits
- Frequent early evaluations for TTTS if monochorionic
- After 32 wks: weekly antenatal care visits, including ultrasound, to monitor growth
Childbirth:
- C-section if indicated e.g. breech presentation
- Vaginal delivery: diamniotic twins ≥ 37wks with one fetus in vertex presentation
- Induction of labour if ≥ 38wks
Ectopic pregnancy:
Definition of ectopic pregnancy?
A pregnancy in which the fertilised egg attaches in a location other than the uterine endometrium
Ectopic pregnancy:
Name the common sites of implantation in ectopic pregnancies?
Fallopian tube (∼95%) - Ampulla (∼70%) - Isthmus ( ∼15%, most dangerous) - Fimbriae & other (∼10%) Ovary (∼3%) Abdomen (∼1%) Cervix (<1%)
Ectopic pregnancy:
Symptoms of ectopic pregnancy?
May be asymptomatic
- Usually lower abdominal pain followed by scanty, dark red bleeding
- Pain is variable; it is often initially colicky as the tube tries to expel the lodged embryo, but then becomes constant
- Other symptoms include syncope and amenorrhoea.
Ectopic pregnancy:
Risk factors for ectopic pregnancy?
- PID
- Previous ectopic
- Surgery involving fallopian tubes
- Endometriosis
- Kartagener syndrome
- Smoking
- Advanced maternal age
- IUD
- IVF
Ectopic pregnancy:
Investigation of a suspected ectopic pregnancy?
- Urine β-hCG will be positive
- Transvaginal ultrasound (TVUS) is investigation of choice. Will show empty uterine cavity and may show ‘blob sign’ in unruptured ectopic
- Exploratory laparoscopy is the most sensitive but is invasive. May be indicated in haemodynamically unstable patients with ?rupture
Ectopic pregnancy:
Management of suspected ectopic pregnancy (symptomatic)?
- Nil-by-mouth
- IV access
- G&S and cross-match
- Pregnancy test
- TVUS
- Laparoscopy or methotrexate dependent on criteria
Ectopic pregnancy:
Criteria for expectant management of ectopic pregnancy?
What does this involve?
- <35mm
- Unruptured
- Asymptomatic
- No fetal heartbeat
- β-hCG <1,000 IU/L
Involves close monitoring over 48hrs, intervening if criteria for medical/surgical management are met
Ectopic pregnancy:
Criteria for medical management of ectopic pregnancy?
What does this involve?
- <35mm
- Unruptured
- No significant pain
- No fetal heartbeat
- β-hCG <1,500 IU/L
Involves giving the patient methotrexate. Patient must be willing to attend follow-up.
Ectopic pregnancy:
Criteria for surgical management of ectopic pregnancy?
What does this involve?
- > 35mm
- Ruptured
- Pain
- Visible fetal heartbeat
- β-hCG >1,500 IU/L
Involves either salpingectomy or salpingotomy
Antenatal care:
When is the booking visit and what does it involve?
- 8-12 weeks (ideally < 10 weeks)
- Involves patient education (alcohol, smoking, diet), BP and BMI check, urine culture and booking bloods
Antenatal care:
What occurs at 10-13+6 weeks?
First ultrasound scan
- Dating
- Down’s syndrome screening, including nuchal scan
Antenatal care:
When is the anomaly scan?
18-20+6 weeks
Antenatal care:
When is anti-D prophylaxis given to rhesus -ve women?
- First dose at 28 weeks
- Second dose at 34 weeks
Antenatal care:
When is external cephalic version offered for breech presentation?
36 weeks
Medications during pregnancy:
What antibiotics should be avoided in pregnancy?
- Tetracyclines
- Aminoglycosides
- Trimethoprim (teratogenic)
- Chloramphenicol
- Clarithromycin
- Fluoroquinolones (-floxacins)
- Metronidazole
Medications during pregnancy:
What antibiotics are preferred during pregnancy?
- Penicillins
- Cephalosporins
- Macrolides (-mycins)
- Nitrofurantoin (avoid near term)
Medications during pregnancy:
What antihypertensives should be avoided during pregnancy?
- Diuretics
- ACE inhibitors/ARBs
- Atenolol
Medications during pregnancy:
What antihypertensives are preferred during pregnancy?
𝗠ums 𝗟ove 𝗛ealthy 𝗡ewborns
- Methyldopa
- Labetalol
- Hydralazine
- Nifedipine
Medications during pregnancy:
Other drugs to avoid during pregnancy?
- Warfarin
- NOACs
- NSAIDs
- Carbimazole
- Antiepileptics (valproate, phenytoin, carbamazepine)
- Methotrexate
- Lithium
- Oral anti-diabetic agents (except metformin)
Intrauterine growth restriction (IUGR):
Maternal factors?
(∼70%)
- Alcohol intake
- Cigarette use
- Cocaine use
- Prescription drugs (e.g. ACE-i)
- Placental insufficiency
- Placenta praevia
- Multiple gestations
IUGR:
Fetal factors?
(∼30%)
- Genetic abnormalities
- Cyanotic congenital heart defects
- Early intrauterine infections
IUGR:
Diagnosis?
- Serial ultrasound scans to diagnose
- Doppler velocimetry for ?placental insufficiency
IUGR:
Treatment?
- Monitoring
- If adverse signs → induce labour/immediate c-section. If < 34 weeks administer steroids first.
Hypertensive pregnancy disorders:
Define gestational hypertension
- Pregnancy-induced hypertension with onset after 20 weeks’ gestation without proteinuria or end-organ dysfunction
Hypertensive pregnancy disorders:
What is hypertension <20 weeks defined as?
- Chronic hypertension
- Can’t be due to pregnancy as BP physiologically decreases before 20 weeks
Hypertensive pregnancy disorders:
Define pre-eclampsia
- New-onset gestational hypertension with proteinuria or end-organ dysfunction
𝗣𝗥𝗘eclampsia: 𝗣roteinuria
𝗥ising blood pressure (hypertension)
𝗘nd-organ dysfunction
Hypertensive pregnancy disorders:
What does HELLP syndrome stand for?
What is it?
- 𝗛aemolysis, 𝗘levated 𝗟iver enzymes and 𝗟ow 𝗣latelets
- A life-threatening form of pre-eclampsia
Hypertensive pregnancy disorders:
Define eclampsia
- A severe form of pre-eclampsia with convulsive seizures and/or coma
Hypertensive pregnancy disorders:
Risk factors for pre-eclampsia?
- Thrombophilia
- Afro-Caribbean ethnicity
- Chronic hypertension
- Obesity
- Diabetes mellitus
- Nulliparity
- Chronic kidney disease
- Smoking generally protective
Hypertensive pregnancy disorders:
Pathophysiology of pre-eclampsia?
- Spiral arteries normally develop into high-capacity vessels
- This is impaired in pre-eclampsia → placental hypoperfusion
- Fetal hypoperfusion → maternal systemic vasoconstriction → hypertension & end-organ damage
Hypertensive pregnancy disorders:
Features of mild/moderate pre-eclampsia?
90% occur after 34 weeks gestation
- Usually asymptomatic
- Nonspecific sx e.g. headaches, visual disturbances, RUQ pain
- Hypertension
- Proteinuria
Hypertensive pregnancy disorders:
Features of severe pre-eclampsia?
- Severe hypertension (BP ≥ 160mmHg)
- Proteinuria/oliguria
- Headache
- Visual disturbances
- RUQ or epigastric pain
- Pulmonary oedema
- Altered mental state
Hypertensive pregnancy disorders:
Features of eclampsia?
- Onset: the majority of cases occur intra-partum and post-partum
- Eclamptic seizures: generalised tonic-clonic seizures
🔺 RUQ pain, visual changes and and hyperreflexia may be warning signs of an impending eclamptic seizure 🔺
Hypertensive pregnancy disorders:
Diagnostic criteria for gestational hypertension?
- New hypertension (BP≥140/90) diagnosed after 20 weeks gestation
Hypertensive pregnancy disorders:
Diagnostic criteria for pre-eclampsia?
New-onset blood pressure ≥ 140/90, >20wks of pregnancy
AND one of the following
- Proteinuria
- Other organ involvement (e.g. renal insufficiency)
Hypertensive pregnancy disorders:
Complications of pre-eclampsia?
Maternal
- Placental abruption
- Acute respiratory distress syndrome
- Cerebral haemorrhage
- Eclampsia
- Death
Fetal
- IUGR
- Preterm birth
- Fetal death
Hypertensive pregnancy disorders:
Prevention of pre-eclampsia?
Aspirin 75mg daily from 12 weeks until birth in high risk patients
Hypertensive pregnancy disorders:
Treatment of pre-eclampsia?
Initial assessment:
- Arrange emergency secondary care assessment for any woman with suspected pre-eclampsia
- Women with BP ≥160/110 are likely to be admitted and observed
Further management:
- Oral labetalol first-line management for BP (nifedipine and hydralazine if contraindicated)
- IV magnesium sulfate for eclampsia prophylaxis
- Delivery of the baby is definitive
Hypertensive pregnancy disorders:
Treatment of HELLP syndrome?
Stabilisation
- Blood transfusions
- Antihypertensives (labetalol)
- IV magnesium sulfate
Delivery
- If ≥34wks
- If maternal/fetal status deteriorating
Diabetic disorders in pregnancy:
Define gestational diabetes
- Impaired glucose tolerance diagnosed during pregnancy
Diabetic disorders in pregnancy:
Epidemiology of gestational diabetes?
- ∼4% of pregnancies
- Second commonest medical disorder complicating pregnancy
Diabetic disorders in pregnancy:
Risk factors for gestational diabetes?
- Obesity
- Previous baby ≥ 4.5kg
- Previous gestation diabetes
- First-degree relative with DM
- Ethnicity (South Asian, Afro-Caribbean and Middle-Eastern)
Diabetic disorders in pregnancy:
Gestational diabetes screening?
- Women with a past history of gestational diabetes = OGTT after booking and ∼26wks if first test normal. Self-testing is an alternative.
- Women with other risk factors should receive an OGTT at ∼26wks
Diabetic disorders in pregnancy:
Diagnosis of gestational diabetes (OGTT results)?
5,6,7,8 rule.
Fasting glucose ≥5.6mmol/L
2-hour glucose ≥7.8mmol/L
Diabetic disorders in pregnancy:
Management of gestational diabetes?
- Education and advice
- If fasting plasma glucose level is <7mmol/L trial conservative management
- If glucose not controlled within 1-2wks add metformin
- Add short-acting insulin if this is not effective
- If fasting glucose >7mmol/L → 𝘀𝘁𝗮𝗿𝘁 𝗶𝗻𝘀𝘂𝗹𝗶𝗻
Diabetic disorders in pregnancy:
Management of pre-existing diabetes?
- Encourage weight loss if BMI > 27
- Stop oral agents, apart from metformin, and commence insulin
- Folic acid 5mg from pre-conception to 12 weeks
- Monitor for retinopathy as risk increases during pregnancy
NB: Tight glycaemic control improves pregnancy outcomes
Diabetic disorders in pregnancy:
Complications of gestational diabetes?
- Pre-eclampsia, eclampsia and HELLP syndrome
- UTI
Diabetic disorders in pregnancy:
Prognosis of gestational diabetes?
- Most cases resolve after pregnancy
- 50% risk of recurrence in subsequent pregnancies
- Increased risk of developing DM
Hyperemesis gravidarum:
Definition
Nausea and vomiting
in early pregnancy so severe as to cause severe
dehydration, weight loss or electrolyte disturbance
Hyperemesis gravidarum:
Features
- Nausea & vomiting
- Physical signs of dehydration
- Hypersalivation
- Orthostatic hypotension
Hyperemesis gravidarum:
Management
- Rehydration with IV normal saline
- Antiemetics (metoclopramide/cyclizine)
- Thiamine (can cause Wernicke’s encephalopathy)
Loss of pregnancy:
Describe a threatened miscarriage
- Vaginal bleeding
- Viable intrauterine fetus
- Closed cervical os
Loss of pregnancy:
Describe an inevitable miscarriage
- Heavy bleeding with clots and pain
- Dilated cervical os
Loss of pregnancy:
Describe a missed miscarriage
- Gestational sac which contains a dead fetus <20 weeks without symptoms of expulsion
- May be light vaginal bleeding/discharge. Not usually painful
- Closed cervical os
Loss of pregnancy:
Describe an incomplete miscarriage
- Not all products of conception have been expelled
- Pain and vaginal bleeding
- Dilated cervical os
Loss of pregnancy:
Define miscarriage
- The loss of a uterine pregnancy occuring before 24 weeks gestation
- Can be either through expulsion of the products of conception or the detection of a dead intrauterine fetus.
Loss of pregnancy:
Define stillbirth
- The loss of a uterine pregnancy occuring after 24 weeks gestation
Loss of pregnancy:
Risk factors for loss of pregnancy?
Maternal
- Structural abnormalities of the reproductive organs
- Hypercoagulability (e.g. APS)
- Infections
- Trauma
Fetoplacental
- Chromosomal abnormalities (up to half of all miscarriages)
- Congenital anomalies
Loss of pregnancy:
Management of miscarriage?
Expectant
- Wait 7-14 days for miscarriage to complete
Medical management
- Vaginal misoprostol
- Given with antiemetics and analgesia
Surgical management
- Vacuum aspiration (local anaesthetic as outpatient)
- Operative (done under GA)
Loss of pregnancy:
Management of stillbirth?
- Spontaneous labour usually begins within 2 weeks of intrauterine fetal death
- May be induced with oxytocin
- Vaginal delivery safer than c-section
- Provide privacy and emotional support to parents
Gestational trophoblastic disease:
What is a hydatidiform mole?
- Benign trophoblastic disease
- It may become malignant, infiltrate myometrium and cause metastasis e.g. in the brain
Gestational trophoblastic disease:
Diagnosis of a hydatidiform mole?
β-hCG measurement
- Usually significantly raised (in the hundreds of thousands)
TVUS
- “Snowstorm appearance”
Gestational trophoblastic disease:
Management of a hydatidiform mole?
- Uterine evacuation by dilation and curettage (D&C)
- Monitor β-hCG levels
- Methotrexate if unresolved
Gestational trophoblastic disease:
What is a choriocarcinoma?
- Highly aggressive, malignant tumour of trophoblastic tissue
- Metastasises early
Gestational trophoblastic disease:
Pathophysiology of choriocarcinoma?
- 50% preceded by a hydatidiform mole
- Malignant transformation of cytotrophoblast and syncytiotrophoblastic tissue
Gestational trophoblastic disease:
Diagnosis of choriocarcinoma?
↑↑↑↑β-hCG
Pelvic ultrasound
- Hypervascular on doppler
Uterine D&C
- Histopathological examination
- Both diagnostic and therapeutic
Chest x-ray/ CT chest-abdo-pelvis for staging
Gestational trophoblastic disease:
Management of choriocarcinoma (localised)?
- D&C
- Methotrexate
- Surgery (e.g. hysterectomy)
- Monitor β-hCG for ≥12 months
Gestational trophoblastic disease:
Prognosis of choriocarcinoma?
Cure rate of 95-100%
Antepartum haemorrhage:
What is placental abruption?
Complete or partial separation of the placenta from the uterus prior to delivery
Antepartum haemorrhage:
Risk factors for placental abruption?
- Vascular changes e.g. hypertension, pre-eclampsia
- Abdominal trauma, car accidents
- Previous abruption
- Alcohol and cigarette consumption
- Cocaine use
Antepartum haemorrhage:
How does placental abruption present?
- Continuous vaginal bleeding
- Sudden onset back pain or uterine tenderness
- “Woody hard uterus”
- Fetal distress seen in 60% (decels on CTG)
- Abruption may be concealed (i.e. middle of placenta detaches and forms a hidden pool of blood). Presents with shock out of keeping with visible blood loss.
Antepartum haemorrhage:
How is placental abruption diagnosed?
- Diagnosis is usually clinical
To establish fetal wellbeing:
- Continual monitoring of CTG
- Abdominal ultrasound may estimate weight if preterm. US may also exclude placenta praevia, but has only 25% sensitivity for abruption.
To establish maternal wellbeing:
- FBC, coagulation screen, and crossmatch blood.
- Regular monitoring, ICU involvement if needed.
Antepartum haemorrhage:
How is placental abruption managed?
- ABCDE assessment and resuscitation
Delivery depends on fetal condition:
- Fetal distress → emergency c-section
- No distress, > 37wks gestation → induce labour
- No distress, < 37wks gestation → manage conservatively (steroids if < 34wks, discharge if symptoms resolve, pregnancy is now HIGH-RISK)
Antepartum haemorrhage:
Complications of placental abruption?
- Intrauterine fetal death
- Maternal DIC and hypovolaemic shock
- Increased risk of postpartum haemorrhage
- Uterine rupture
Antepartum haemorrhage:
What is placenta praevia?
The presence of the placenta in the lower uterine segment.
Partial or complete obstruction of the neck of the uterus will result in a high risk of haemorrhage or birth complications.
Antepartum haemorrhage:
Risk factors for placenta praevia?
- Previous placenta praevia
- Previous uterine curettage or c-section
- Maternal age >35
- Multiparity
Antepartum haemorrhage:
Clinical features of placenta praevia?
- Sudden painless vaginal bleeding
- No fetal stress
- Soft, non-tender uterus
Antepartum haemorrhage:
Diagnosis of placenta praevia?
- Digital vaginal examination contra-indicated; may cause haemorrhage
- TVUS gold standard
Antepartum haemorrhage:
Management of placenta praevia?
- Admit all women with bleeding from placenta praevia
- Administer anti-D if available
- Steroids given if < 34wks gestation
- Elective c-section at 39 weeks
Antepartum haemorrhage:
What is vasa praevia?
When a fetal blood vessel runs in the membranes in front of the presenting part
Antepartum haemorrhage:
Features of vasa praevia?
- Painless vaginal bleeding occurring suddenly, soon after rupture of membranes
- Fetal distress (e.g. bradycardia)
- Fetal death can occur quickly due to exsanguination
Antepartum haemorrhage:
Diagnosis of vasa praevia?
- Usually clinical, correlating maternal status with CTG findings
- Can be diagnosed with Doppler ultrasound
Antepartum haemorrhage:
Management of vasa praevia?
Emergency caesarian section
Chorioamnionitis:
What is it?
Infection of the placenta, membranes, and amniotic fluid
Chorioamnionitis:
Risk factors?
- Prolonged labour or premature rupture of membranes
- Bacterial colonisation of the vaginal tract
- Multiple digital vaginal examinations/invasive procedures
Chorioamnionitis:
Clinical features?
Maternal
- Fever
- Tachycardia
- Uterine tenderness
- Malodourous amniotic fluid/vaginal discharge
Fetal
- Tachycardia (HR >160bpm)
Chorioamnionitis:
Diagnosis?
Largely clinical; supported by:
- Blood tests (e.g. leucocytosis)
- Bacterial cultures from urogenital secretions/liquor
- High vaginal swab
- CTG
Chorioamnionitis:
Management?
- Immediate IV antibiotics and birth, whatever the gestational age of the pregnancy
- IV erythromycin; co-amoxiclav contraindicated as increases the risk of necrotising enterocolitis
Labour:
What are Braxton-Hicks contractions?
“False labour”
- Physiological contractions, beginning in the second or third trimester
- Short, infrequent (typically ≤2/hr) contractions, aimed at positioning the fetus correctly in the uterus
Labour:
What are the two phases of the first stage of labour?
The latent phase and the active phase
Labour:
What is the latent phase of labour 1?
When the cervix dilatates slowly for the first 4-6cm, may take as long as 20hrs in nulliparous women.
Labour:
What is the active phase of labour 1?
Faster cervical dilatation, ∼1cm/hr. Lasts until 10cm dilatation (fully dilated),
Labour:
What is the second stage of labour?
The time between full cervical dilatation and the delivery of the baby.
Labour:
What is the passive phase of labour 2?
- Lasts from full dilatation until the fetal head reaches the pelvic floor and the mother feels the urge to push
- Rotation and flexion are commonly completed at this stage
Labour:
What is the active phase of labour 2?
When the mother is pushing; the pressure of the fetal head against the pelvic floor creates an irresistible urge to bear down, though epidural may prevent this
Labour:
What steps typically occur during delivery?
- Extension as the fetal head reaches the perineum
- The head then restitutes, rotating 90º to lie transverse
- The next contraction typically delivers the shoulders
- The anterior shoulder comes first, followed by the posterior shoulder, followed by the rest of the body
Labour:
What is the third stage of labour?
How long does it last and how much blood is lost?
- The time from the delivery of the baby to the delivery of the placenta
- Usually lasts ∼15 minutes, typical blood loss ≤500ml
Mechanics of childbirth:
What is fetal lie?
Relation of the fetal long axis to the uterine long axis:
- Longitudinal (most common)
- Transverse
- Oblique
Mechanics of childbirth:
What is fetal presentation?
The part of the fetus that overlies the pelvic inlet:
- Cephalic (head; most common)
- Breech (buttocks or feet)
Mechanics of childbirth:
What is fetal station?
The position of the presenting part above or below the ischial spines, e.g. -1 = 1cm above, +2 = 2cm below.
Preterm delivery:
What is it?
Delivery occurring after 24 weeks and before 36 weeks gestation
Preterm delivery:
Management?
- If <34 weeks give steroids to delay birth and mature fetal lungs
- Magnesium sulfate for neuroprotection
- Antibiotics in labour
- Electronic fetal monitoring if >26 weeks
- Manage conservatively if <26 weeks
Amniotic fluid embolism:
What is it?
Rare, but life-threatening condition caused by the entry of fetal cells and debris from the amniotic fluid into the maternal circulation.
Amniotic fluid embolism:
Clinical features?
Acute onset of:
- Disseminated intravascular coagulation (DIC)
- Hypoxia
- Hypotension
- Cardiac arrest
Amniotic fluid embolism:
Diagnosis?
Mostly clinical,
- Respiratory acidosis
- Increased prothrombin time (PT)
Amniotic fluid embolism:
Management?
- Maternal resuscitation
- Emergency c-section
Postpartum haemorrhage:
Define primary postpartum haemorrhage?
Loss of >500ml of blood <24 hours after vaginal delivery or >1000ml if c-section
Postpartum haemorrhage:
Define secondary postpartum haemorrhage?
“Excessive” blood loss occurring between 24 hours and 6 weeks after delivery
Postpartum haemorrhage:
Define major obstetric haemorrhage
Best defined as >1500ml of blood loss which is continuing
Postpartum haemorrhage:
Causes of primary PPH?
The 4 T’s:
- Tone (70-80%) - uterine atony
- Trauma - genital tract trauma
- Tissue - retained products of conception
- Thrombin - coagulopathy
Postpartum haemorrhage:
Risk factors for uterine atony?
𝗔𝗘𝗜𝗢𝗨:
𝗔natomical e.g. fibroids, fetal/uterine abnormalities
𝗘xhausted uterus (prolonged labour, oxytocin use)
𝗜nfections
𝗢verdistended 𝗨terus - multiple pregnancy
Postpartum haemorrhage:
Initial management of uterine atony?
- IV oxytocin
- Protaglandins e.g. misoprostol
- Bimanual compression of the uterus
- Tranexamic acid (anti-fibrinolytic) if above fail
Postpartum haemorrhage:
Surgical management of uterine atony?
- Uterine balloon tamponade
- Compression sutures (“B-Lynch sutures”)
- Surgical ligation of uterine or internal iliac arteries
- Hysterectomy as last line, life-saving treatment
Postpartum haemorrhage:
What is Sheehan syndrome?
Postpartum necrosis of the pituitary gland. Usually occurs after postpartum haemorrhage but may occur spontaneously.
Postpartum period:
What is lochia?
A benign vaginal discharge usually passed for around 4 weeks after delivery
Postpartum period:
Breastfeeding physiology
- Delivery of the placenta → drop in progesterone → rise in prolactin
- Suckling maintains prolactin secretion
- Prolactin stimulates milk production
- Oxytocin stimulates the milk ejection reflex and also plays an important role in mother-baby bonding
Postpartum mental health disorders:
“Baby blues” features?
- Occurs in ≤85% of pregnancies
- Typically occurs within 1 week of delivery, resolves within ∼2 weeks
- Milder symptoms e.g. low mood, crying and fatigue
- Treatment is reassurance
Postpartum mental health disorders:
Scoring system for assessing possible postpartum depression?
Edinburgh Postnatal Depression Scale
Postpartum mental health disorders:
Features & diagnosis of postnatal depression?
- Affects ∼10% of pregnancies
- More severe symptoms than “baby blues”, same symptoms as major depression
- Diagnosis with the Edinburgh Postnatal Depression Scale
Postpartum mental health disorders:
Management of postnatal depression?
- SSRIs (paroxetine recommended as less expressed in breast milk, fluoxetine avoided as long half-life)
- CBT
Postpartum mental health disorders:
Postpartum psychosis features?
- 0.1% of pregnancies
- Typically develops within 2 weeks
- Psychotic features e.g. delusions/hallucinations
- Other features include suicidality, depression, disinhibition
Postpartum mental health disorders:
Postpartum psychosis management?
- Admission required
- Antipsychotics and major tranquillizers used
Obstetric emergencies:
What is shoulder dystocia?
Impaction of the anterior shoulder on the maternal pubic symphysis
Obstetric emergencies:
Management of shoulder dystocia?
𝗛𝗘𝗟𝗣𝗘𝗥𝗥𝗭
𝗛elp (shout)
𝗘valuate for an episiotomy (risk of perineal tear)
𝗟egs to chest (McRobert’s manoeuvre)
𝗣ubic pressure (suprapubic pressure to dislodge shoulder)
𝗘nter internal rotational manoeuvres
𝗥emove (birth) posterior arm
𝗥oll mother onto all-fours
𝗭avanelli manoeuvre (rarely done, push fetal head back into pelvis and perform emergency c-section)
Obstetric emergencies:
Complications of shoulder dystocia?
Fetal
- Brachial plexus injury (Erb’s/Klumpke’s palsy)
- Clavicle/humerus fracture
Maternal
- Perineal tears
- Postpartum haemorrhage
Obstetric emergencies:
What is umbilical cord prolapse?
This occurs after the membranes have ruptured and the umbilical cord descends below the presenting part
Obstetric emergencies:
Features of umbilical cord prolapse?
- Abrupt changes on CTG showing bradycardia, or recurrent, severe variable/late decelerations
- Cord may be visible/palpable in the birth canal
Obstetric emergencies:
Management of umbilical cord prolapse?
- The presenting part must be kept off the cord with a combination of tocolytics and the examining finger
- The patient should go onto all fours, awaiting delivery by the safest available method
- C-section is standard, although instrumental delivery may be preferable in some cases