Obs 5 Flashcards
(59 cards)
1
Q
What are the RFs for a multiple pregnancy?
A
- Advanced maternal age
- IVF
- Previous multiple pregnancy
2
Q
Define chorion and amnion
A
Chorion = number of placentae
Amnion = number of amniotic sacs
3
Q
Describe monozygous twins
A
Division of fertilised egg = IDENTICAL (20% of twins)
Dichorionic diamniotic:
- Cleavage days 1-3
- 2 placenta and 2 amniotic sacs
- S/S: λ sign
Monochorionic diamniotic:
- Cleavage days 4-8
- 1 placenta (share), 2 amniotic sacs
- S/S: T-sign
Monochorionic monoamniotic:
- Cleavage days 8-12
- 1 placenta (share), 1 amniotic sac (share)
- S/S: T-sign, ‘entangled cords’
Conjoined twins:
- Cleavage days 13-15
4
Q
Describe dizygous twins
A
Fertilisation of 2 ovum by 2 different sperm = NON-IDENTICAL (80% of twins)
- DCDA – separate placentae, amnions, chorions
5
Q
How is GA estimated for multiple pregnancies?
A
Offer 1st trimester USS when CRL 45-84 mm (11-13+6 weeks) to determine: EGA, chorionicity, and to screen for Down syndrome (use largest baby to estimate GA)
6
Q
How is chronionicity detected for multiple pregnancies?
A
> Refers to the type of placentation (this is the most important feature to an obstetrician)
- Detect at time of detecting twin/triplet pregnancy by USS using number of placental masses, lambda (dichorionic) or T-sign (monochorionic) and membrane thickness
- Examine junction between the inter-fetal membrane and the placenta
- In DC pregnancies = triangular placental tissue projection (λ sign) into base of the membrane
- In MC pregnancies = no placental tissue projection (T-sign) into the base of the membrane
- If presenting after 14 weeks, determine chorionicity using all of membrane thickness, lambda sign, number of placental masses and disconcordant foetal sex
7
Q
What are the S/S of multiple pregnancies?
A
(Asymptomatic):
1st trimester = incidental on USS, hyperemesis (increased βHCG)
2nd trimester = large for dates, multiple parts on abdominal exam
Abdominal exam = increased SFH, multiple parts, >1 FH
8
Q
What is the antenatal management of a multiple pregnancy?
A
- FBC at 20-24w (query extra supplementation of iron or folic acid, repeat at 28w)
- BP (increased chance of eclampsia)
- GTT (increased likelihood of diabetes) - 16w (every 2w) for MC, 20w (every 4w) for DC
- TTTS screening = every 2 weeks from 16-24 weeks – if MC
- General growth scans = after 24w (every 2 or 4 weeks)
Serial USS for foetal growths:
- MC twins = scan at 12, 16 and then every 2 weeks until delivery
- DC twins = scan at 12, 20 and then every 4 weeks until delivery
- MC/ DC triplets = scan at 12, 16 and every 2 weeks until delivery
- TC triplets = scan at 12, 20 and every 4 weeks until delivery
9
Q
Describe the specialist care for multiple pregnancies
A
- Uncomplicated monochorionic diamniotic twin pregnancy should be offered at least 9 appointments with a healthcare professional, at least 2 should be with a specialist obstetrician
- Uncomplicated dichorionic twin pregnancy should be offered at least 8 appointments and at least 2 with a specialist obstetrician
- Uncomplicated monochorionic triamniotic or dichorionic triamniotic pregnancy should be offered at least 11 appointments and at least 2 with a specialist obstetrician
- Uncomplicated trichorionic triamniotic triplet pregnancy should be offered at least 7 scans and at least 2 with a specialist obstetrician
10
Q
How is pre-term birth in multiple pregnancies prevented?
A
Do NOT use the following routinely to prevent spontaneous preterm birth:
- Bed rest at home or in hospital
- IM or vaginal progesterone
- Cervical cerclage
- Oral tocolytics
- Corticosteroids will be useful if preterm birth is likely (should be targeted)
11
Q
Describe the birth of multiple pregnancies
A
- 60% of twin pregnancies result in spontaneous birth before 37 weeks
- Offer continuous foetal monitoring (CTG); if needed: scalp electrode and foetal blood monitoring
- Offer elective birth if (if declined > weekly obstetrician appointments):
- Uncomplicated monochorionic twin – from 36 weeks (after course of steroids)
- Uncomplicated dichorionic twin – from 37 weeks
- Uncomplicated triplet – from 35 weeks (after a course of steroids)
Vaginal delivery (first twin is in the cephalic position; 2nd may be breech but this is ok)
- Second breech baby can be turned using Internal Pedalic Version (IPV)
12
Q
Describe the foetal complications of multiple pregnancies
A
IUGR:
(and discordant IUGR: when one baby is SGA and the other normal or LGA)
- Monitored with EFW discordance (not SFH)
- Difference in size >20% is an indicator of IUGR
Intra-uterine death (IUD):
- For dizygotic twins, the other twin will be fine
- In monochorionic, this can be bad as the BP will drop in the surviving twins’ placenta > neurological damage in the surviving twin in 25%
Down Syndrome:
(greater absolute risk as same risk PER baby so increased TOTAL risk)
Also:
- Structural Abnormalities (2x in monozygotic babies)
- Twin-to-Twin Transfusion Syndrome (TTTS)
- Malpresentation
- Premature
13
Q
What are the maternal complications of multiple pregnancies?
A
- Pre-eclampsia (more risk of abnormal vasculature development)
- Hyperemesis gravidarum (more bHCG)
- GDM (more placental lactogen and placental steroids so more likely to tip into diabetes)
- APH, PPH (stretched uterus)
- Anaemia and thrombocytopaenia (more required to sustain the two children)
14
Q
What is TTTS?
A
Results from an unbalanced blood supply through placental anastomoses in monochorionic twins
Donor twin = growth restriction, renal tubular dysgenesis, and oliguria
Recipient twin = visceromegaly and polyuria
Mother = sudden abdomen size increase, SOB
- Start diagnostic monitoring with USS from 16-24 weeks on a 2-weekly basis
- Delivered by 34-37 weeks
- New treatment (<26w) = foetoscopic laser ablation of vascular anastomoses
- New treatment (>26w) = delivery
15
Q
What are RFs for high-risk pregnancies?
A
- Any previous complicated pregnancies (biggest risk for another abnormal pregnancy)
- Age <15yo or >35yo
- Pre-pregnancy weight under 45kg or obese
- Height under 5 ft (1.5m)
- Incompetent cervix
- Uterine malformations
- Small pelvis
- Being single, smoker, alcohol, illicit drugs
- No access to early prenatal care
- Low socioeconomic status
- Hx of recurrent miscarriages
- Hypothyroid / Hyperthyroid
16
Q
What is the management of high-risk pregnancies?
A
- Continued surveillance for high risk patients – more frequent scans
- Offer high dose folate 5mg – also given to…
- Previous child with NTD
- Diabetes mellitus
- Woman on an anti-epileptic
- Obesity
- HIV positive taking co-trimoxazole
- Sickle cell disease
- Offer low dose aspirin (75mg, OD) as prophylaxis for pre-eclampsia
17
Q
Define obesity in pregnancy
A
Obesity = BMI >30kg/m2
18
Q
What is the aetiology of obesity in pregnancy?
A
Pre-existing obesity – poor diet, lack of exercise
Fluid retention – polyhydramnios, heart, kidney, liver failure
19
Q
What are the S/S of obesity in pregnancy?
A
Obesity
+Associated conditions may be present:
- GDM
- Pre-eclampsia
- Infections
20
Q
What are the investigations for obesity in pregnancy?
A
- BMI monitoring
- Bloods – FBC, LFT, UE, cholesterol, OGTT
- USS – liquor volume, foetal growth scans
21
Q
What is the management of obesity in pregnancy?
A
Conservative:
- More exercise, better diet, vitamin D supplementation
Labour planning:
- Assess risk of giving birth via vaginal delivery and whether there needs to be induction/CS
Post-natal follow up:
- T2DM testing
22
Q
What are the complications of obesity in pregnancy?
A
- GDM
- Pre-eclampsia
- Infections
- Overdue pregnancy, labour difficulties, CS or miscarriage
Prognosis – almost 1/3 maternal deaths are in obese mothers
23
Q
What is oligohydramnios?
A
Decreased volume of amniotic fluid, <5th centile, deepest pool <2cm
24
Q
What are the causes of oligohydramnios?
A
Reduced input fluid:
- Placental insufficiency
- Pre-eclampsia
Reduced output fluid:
- Structural pathology (renal agenesis, atresia of ureter / urethra)
- Medications (ACEi, NSAIDs)
Lost fluid:
- Amniotic rupture
25
What are the S/S of oligohydramnios?
Commonly asymptomatic
- History of fluid leak PV, rupture of membranes
- Abdominal exam – decreased fundal height, foetal parts easily palpable
- Speculum – assess for membrane rupture if appropriate
26
What are the investigations for oligohydramnios?
- Speculum - assess for membrane rupture
- USS – liquor volume, foetal anomalies
- CTG– foetal wellbeing
27
What is the management of oligohydramnios?
*Planned birth in an obstetric unit is recommended*
**Pre-Term:**
- Expectant management
- Ongoing antepartum surveillance
- Continuous fetal heart rate monitoring during labour
- Delivery if further abnormalities arise
**Term:**
- Delivery is often the most appropriate management
28
What are the complications of olighydramnios?
**Labour:**
- Increased incidence of CTG abnormalities
- Meconium liquor
- Emergency CS
**Neonate:** can cause POTTER SEQUENCE
- Pulmonary hypoplasia
- Twisted faces
- Twisted skin
- Extremity deformities
- Renal agenesis
Prognosis – increased perinatal mortality rates with early onset oligohydramnios
29
What is polyhydramnios?
Increased volume of amniotic fluid, above 95th centile, or deepest pool greater than 8 cm.
30
What are the causes of polyhydramnios?
**Failure of foetal swallowing:**
- Neurological / chromosomal abnormalities
- GIT (duodenal atresia, oesophageal atresia, TOF)
**Foetal polyuria:**
- Maternal diabetes
- TTTS
**Also:**
- Congenital infections
31
What are the S/S of polyhydramnios?
- Symptoms of underlying cause
- Abdomen – increased fundal height, impalpable foetal parts, tense abdo
32
What are the investigations for polyhydramnios?
- USS - liquor volume, foetal growth
- Umbilical artery dopplers - exclude foetal anomalies
- Other – exclude maternal diabetes
33
What is the management of polyhydramnios?
- Antenatal monitoring of foetus, ensure diabetes control, paediatrician present at delivery
- Amnioreduction (if gross polyhydramnios / discomfort)
- COX inhibitors to decrease foetal urine output
34
What are the complications of polyhydramnios?
- PTL
- Malpresentation
- Placental abruption
- Cord prolapse
- PPH
- Increased risk CS
Prognosis – increased perinatal morbidity and mortality, related to PTL/congenital
35
Define a low-lying placenta
Placental edge is <2cm from internal os on TVUSS
36
What is placenta praevia?
Placenta lies over the internal os (diagnosed at ≥32 weeks)
37
What are the types of placenta praevia?
*Classical grading:*
- **I** = placenta does not cover internal cervical os but is low lying
- **II** = placenta reaches internal os but doesn't cover it (lower edge reaching internal os)
- **III** = placenta covers the internal os before dilation but not when dilated / lower edge partially covering the internal os
- **IV ('major')** = placenta completely covers the internal os
38
What are the RFs for placenta praevia?
- Multiple pregnancy
- Increased maternal age
- Previous uterine surgery (i.e. CS)
- Previous praevia history
- Smoking
- IVF (6x increased risk)
39
What are the S/S of placenta praevia?
- **Painless bright red PV bleeding in 2nd or 3rd trimester**
- Can have small bleeds before large
- Potential signs of shock (shock in proportion to visible loss)
- Uterus not tender
- Lie and presentation may be abnormal
- Fetal heart usually normal
- Coagulation problems rare
40
What are the investigations for placenta praevia?
*Digital vaginal examination should not be performed before an USS as it may provoke a severe haemorrhage (speculum ok to assess bleeding)*
- **1st line diagnosis: TVUSS**
- Bloods – FBC, clotting studies, G&S, U&E, LFT
- If mother RhD -ve: Kleihauer test (check level of foetal blood in maternal circulation) +/- administer anti-D
- CTG
*Placenta praevia often picked up on routine 20w abdominal USS*
41
What is the management of placenta praevia?
**1. Picked up on 20w anomaly scan:**
- Only 10% go on to have a low-lying placenta later in pregnancy
- Rescan at 32 weeks
**2. USS at 32 weeks:**
- Still present and grade I/II: Rescan at 36 weeks
- Still present and grade III/IV: Admit at 34 weeks with CS at 37 weeks
**3. USS at 36 weeks:**
- Grade I = vaginal delivery
- Grade III/IV = CS
**Also:**
- Antenatal corticosteroids from 34-36 weeks (can be earlier if at risk of PTL)
- Tocolysis (facilitate antenatal corticosteroids)
- General advice: NOT to have sex if low-lying placenta or placenta praevia
**If a woman with known placenta praevia goes into labour prior to the elective C section, an emergency C section should be performed due to the risk of PPH**
42
What is the management of placenta praevia with bleeding?
- Admit and ABC approach (IV access and fluids)
- Bloods: FBC, G&S, consider crossmatch, Kleihauer test
- Anti-D if Rh-D -ve and Kleihauer test
- Admit at least until bleeding has stopped (and keep them in for 48 hours to observe)
- If not able to stabilise = emergency C section
- If in labour or term reached = emergency C section
**Scans:**
- CTG (if >27 weeks)
- Umbilical artery dopplers (every 2 weeks)
- Growth scan
43
What are the complications of placenta praevia?
**Maternal:**
- Haemorrhage – antepartum and postpartum
- DIC
- Hysterectomy
- Maternal mortality is 1 in 300
**Foetal:**
- IUGR
- Death
44
What is vasa praevia?
**Foetal blood vessels connecting the umbilical cord to the placenta travel across the internal cervical os and below the foetal presenting part, unprotected by placental tissue or umbilical cord**
> When baby descends, they can rupture the vessels
45
What are the 2 types of vasa praevia?
**Type 1 VP** = vessels connect a velamentous umbilical cord to the placenta (single or bilobed placenta)
**Type 2 VP** = vessels connect the lobes of the placenta (single or bilobed) to 1 or more succenturiate lobes (accessory lobes)
46
What is Benckaiser’s haemorrhage?
The haemorrhage of blood when the vessels are ruptured
47
What are the RFs for vasa praevia?
- Foetal anomaly (bilobed placenta or succenturiate lobes)
- History of low-lying placenta in 2nd trimester
- Multiple pregnancies
- IVF
48
What are the S/S of vasa praevia?
**Typical picture = ROM > fresh PV bleeding + foetal bradycardia**
- After the membranes rupture, the veins alone can’t hold the weight of the baby > bleeding
- Foetal HR abnormalities – decelerations, bradycardia, sinusoidal trace, foetal demise
- O/E > you can palpate the vessels in the membranes, amnioscope can directly visualise this
49
What are the investigations for vasa praevia?
Can be clinical based on sx
- Usually diagnosed via TVUSS with Doppler
- VE - may be able to detect pulsating foetal vessels inside internal os
- Kleihauer test (measures amount of foetal Hb in a mother’s bloodstream)
- Haemoglobin electrophoresis – identify if foetal or maternal blood (takes a long time)
- Doppler USS
50
What is the management of vasa praevia?
**C-section**
>Rapid delivery + aggressive resuscitation including use of blood transfusion if required are essential
51
What are the complications of vasa praevia?
**Foetal mortality if presenting with haemorrhage is 60% but if identified antenatally its 3%**
- No major maternal risk
- Foetus: Loss of relatively small amounts of blood can have major implications for the foetus
52
What is placental abruption?
Separation of the placenta from the uterine wall before delivery (>24 weeks; if <24w, miscarriage)
Haemorrhage may be concealed (20%) or revealed (80%)
53
What are the RFs for placental abruption?
- Previous placental abruption
- HTN
- Previous APH
- PPROM
- Abdominal trauma
- Smoking, cocaine
- Polyhydramnios
- Idiopathic
*Although most cases occur in low-risk pregnancies*
54
What are the S/S of placental abruption?
**Constant abdominal pain ± PV bleeding (if revealed – 80%), SUSTAINED contractions**
*On examination:*
- General – shock out of keeping with visible loss
- Abdomen – hypertonic “woody” tender uterus
- Speculum – assess bleeding
- Vaginal exam (NOT in praevia) – cervical dilatation
- Normal lie and presentation
- Fetal heart: absent/distressed
- Coagulation problems
- Beware pre-eclampsia, DIC, anuria
55
What is a key difference between placenta praevia and placental abruption?
Praevia = bleed, no pain
Abruption = bleed, pain
56
What are the investigations for placental abruption?
- Basic obs
- Abdominal exam
- Bloods – FBC, clotting, U&E, crossmatch
- CTG for baby
- TVUSS – exclude praevia – abruption unlikely to be present unless very large, may show retroplacental collection of blood
If unsure if praevia, DO NOT BIMANUAL
57
What is the management of placental abruption?
**Mild:**
- If preterm and stable: conservative management with close monitoring > IOL at term
- Admit for at least 48 hours or until bleeding stops
- Anti-D Ig followed by Kleihauer test
- Foetus alive and >36 weeks without distress = vaginal delivery
**Severe:**
- ABC > 2x wide bore cannulae, fluids, blood transfusions, correct coagulopathies
- Foetus alive and >36 weeks and distress = Emergency CS
- Corticosteroids for foetal lung development (between 24-34+6w)
- Consider IOL if foetal compromise
- Foetus dead = induce vaginal delivery
58
What are the complications of placental abruption?
**Maternal:**
- Haemorrhage (APH, PPH)
- DIC
- Renal failure
- “Couvelaire uterus” (extravasation of blood into myometrium and beneath the peritoneum > very hard uterus)
- Sheehan syndrome
**Foetal:**
- Birth asphyxia
- Death
59
What antenatal Down Syndrome screening is offered?
**Combined test is now standard:**
- Should be done between 11 - 13+6 weeks
- High HCG, low pregnancy-associated plasma protein A (PAPP-A), thickened nuchal translucency
**Quadruple test:**
- If women book later in pregnancy the quadruple test should be offered between 15 - 20 weeks
- Low Alpha-fetoprotein, low unconjugated oestriol, high HCG and high inhibin A
