Antenatal Care Flashcards
When are women screened for anaemia in pregnancy
- booking visit 8-12w
- 28w
Why does anaemia occur during pregnancy
increased plasma volume diluting the Hb
What are the normal ranges of Hb during pregnancy
- > 110 g/l at booking
- >105 g/l at 28 week
What is the management of anaemia in pregnancy
- Iron if low Hb or ferritin
- B12: test for pernicious anaemia, if not B12 injection or tablet if mild
- Folate: should be taking 400mcg, if deficient, take 5mg
What is gestational diabetes
diabetes triggered by pregnancy, that usually resolves after they have given birth. It is a result of reduced insulin sensitivity.
What are the risk factors of gestational diabetes
- Raised BMI (>30)
- Previous gestational diabetes
- Asian, black Caribbean, Middle Eastern
- Previous macrocosmic baby (or large for dates baby on scans)
- Family history of diabetes (first degree relative)
When is the oral glucose tolerance test done
Booking
26 weeks
How is the oral glucose tolerance test conducted
- Performed in the morning after a fast (can drink water)
- They drink a 75g glucose drink at the start of the test (usually lucozade)
- Blood sugar is measured before the sugar drink (fasting) and then at 2 hours
What values on oral glucose tolerance test suggest gestation diabetes
At baseline > 5.6
At 2 hours >7.8
What is the management of gestational diabetes
- Joint diabetes / antenatal clinics
- Fasting glucose < 7 trial of diet and exercise
- Fasting glucose > 7 start insulin
- Fasting glucose > 6 and macrosomia (or other complications) start insulin
What is the management of pregnant women with pre-existing diabetes
- Metformin is the only safe oral agent
- Most women are switched to insulin only
- Closer monitoring is required
- Folic acid (5mg) should be taken pre-conception to 12 weeks gestation
- Retinopathy screening should be performed during pregnancy as this can progress rapidly
What is small for gestational age
Defined as a fetus that has an estimated fetal weight (on ultrasound) or abdominal circumference below the 10th centile for their gestational age.
What are the causes for SGA
- constitutionally small
- Fetal Growth Restriction (FGR) AKA Intrauterine growth restriction (IUGR)
- Abnormal SGA, the baby is small due to a genetic or structural abnormality.
- Multiple pregnancy
What is fetal growth restriction
small fetus (or a fetus that is not growing as expected) due to a pathology reducing the amount of nutrients and oxygen being delivered to the fetus.
Other features suggested of SGA
- reduced liquor volume
- abnormal doppler studies
- reduced fetal movements
- abnormal CTGs.
Causes of FGR
- Idiopathic
- Pre-eclampsia
- Maternal smoking
- Maternal alcohol
- Anaemia
- Malnutrition
- Infection
Children who are FGR are disposed to what conditions later in life
HTN
T2DM
Risk factors for FGR babies
Previous SGA baby Obesity Smoking Diabetes Existing hypertension Pre-eclampsia Antiphospholipid syndrome Older mother (>35) Low levels of Pregnancy‑Associated Plasma Protein‑A (PAPPA) Antepartum haemorrhage Multiple pregnancy
What is the management of FGR
- Treat underlying cause e.g. pre-eclampsia
- Careful monitoring of growth and health antenatally
- Get paediatricians involved at birth of baby
What investigations should be carried out if suspecting an FGR baby
- ultrasound monitoring of growth and amniotic fluid volume
- umbilical artery dopplers, ductus venous dopplers
- CTGs
What is large for gestational age
Babies are defined as being large for gestational age (also known as macrosomia) when they are born at a weight more than 4kg.
What are the causes of large for gestational age
Constitutional Maternal diabetes Previous macrosomia Maternal obesity or rapid weight gain Overdue Male baby
What are the risks of LGA to the mother
Shoulder dystocia Failure to progress Perineal tears Instrumental delivery / caesarean Post partum haemorrhage Uterine rupture (rare)
What are the risks of LGA to the baby
Birth Injury (Erbs palsy, clavicular fracture, fetal distress and hypoxia)
Neonatal hypoglycaemia
Obesity in childhood and later life
Why is chickenpox dangerous in pregnancy
- varicella pneumonitis
- fetal varicella syndrome
- Severe neonatal varicella infection (if mum is infected around delivery)
How do you establish immunity of mum regarding chickenpox
- Mothers that have previously had chickenpox are immune and safe
- If in doubt test IgG levels for immunity (positive = immune)
What do you post-exposure to the chicken pox in pregnant woman - previously had chicken pox
Nothing, they’re safe
What do you post-exposure to the chicken pox in pregnant woman - not immune
- IV varicella immunoglobulins as prophylaxis against developing chickenpox. This should be given within 10 days.
- 24 hours aciclovir if chicken pox rash has started
What are the features of congenital rubella syndrome
- Sensorineural deafness
- Congenital heath disease
- Cataracts
- Several other features
Should pregnant woman who are not immune recieve the rubella vaccine
No it’s a live virus, non immune woman should be given the vaccine after pregnancy
What are the complications of twin pregnancies
Anaemia Polyhydramnios Hypertension IUGR Prematurity Increased perinatal mortality Malpresentation Postpartum haemorrhage Twin-twin transfusion syndrome
What is twin-twin transfusion syndrome
- There is a connection between the blood supplies of the two babies
- The recipient gets the majority of the blood, and can become fluid overloaded (with polyhydramnios)
- The donor is starved of blood, and can become anaemia
.
What is the management of severe twin-twin transfusion syndrome
laser treatment to destroy the connection between the two blood supplies
What are monozygotic twins
identical - come from single zygote
What are dizygotic twins
non-identical (come from two different zygotes)
What is mono-amniotic vs diamniotic twins
one vs two amniotic sac
What is mono-chorionic vs dichorionic
one vs two placentas
What is the delivery of mono-amniotic twins
elective caesarean section at around 32-34 weeks.
What is the delivery options of diamniotic twins
- aim delivery 37-38 weeks
- Vaginal delivery is possible when the presenting twin is cephalic presentation. The second baby may require caesarean section after successful delivery of the first baby.
- Elective caesarean is generally advised when presenting twin is not cephalic presentation.
What antenatal care should be given during a twin pregnancy
- 5mg of folic acid
- Iron supplements
- Vitamin D
- Close monitoring
- Induction / section between 37 and 38 weeks for diamniotic twins.
- Steroids are given prior to delivery to mature the fetal lungs
What is the increase scanning requirements of twin pregnancies
2 weekly scans from 16 weeks for monochorionic twins
4 weekly scans from 20 weeks for dichorionic twins
What are you looking for on US during twin pregnancies
- growth restriction
- twin-twin transfusion syndrome
Why is delivery of twin before 38 weeks
associated with increased fetal death
What is the combined test
- Weeks 11-14
- US: Nuchal translucency
- beta-HCG)
Pregnancy‑Associated Plasma Protein‑A (PAPPA)
What is nuchal translucency
thickness of the back of the neck of the fetus – Downs Syndrome is a cause of thickness >6mm)
wHat might you see in the combined test if child has down syndrome
- Nuchal translucency >6mm
- High bHCG
- Low PAPPA
What is the triple test
- Weeks 15-20
- Beta-HCG -a higher result indicates greater risk
- Alpha-fetoprotein (AFP)
- Serum oestriol (female sex hormone)
wHat might you see in the triple/quadruple test if child has down syndrome
- High bHCG
- Low AFP
- Low oestriol
- High inhibin
What is the quadruple test
- Weeks 15-20
- Inhibin-A
- AFP
- bHCG
- Oestriol
Who is offered amniocentesis/chorionic villous sampling
Risk above 1 in 150
What is amniocentesis
ultrasound guided aspiration of some amniotic fluid using a needle and syringe. This is later in pregnancy once enough amniotic fluid makes it safer to take a sample.
What is Chorionic villus sampling
ultrasound guided biopsy of placental tissue. This is used when testing is done earlier in pregnancy (before 15 weeks).
What is placenta praevia
the placenta is lying in the lower portion of the uterus, at a lower point than th presenting part of the fetus. It can lie close to the opening to the cervix, or be covering it.
1-2% of pregnancies
What is considered a major praevia
covers the internal cervical OS
What is considered a minor praevia
doesn’t covers the internal cervical OS
What are the risk factors for placenta praevia
Previous caesarean sections
Older maternal age
Structural uterine abnormalities (e.g. fibroids)
If a placenta praevia is not diagnosed on an early pregnancy scan, what is the main presentation
painless vaginal bleeding - usually around 36 weeks
What is the management of placenta praevia
- Rest and avoid intercourse
- Avoid vaginal examination / speculum unless by experienced obstetrician
- Ultrasound at 34 weeks gestation (or earlier if bleeding) to assess the placental position.
What happens if the placenta remains over the os at 34 weeks
repeat scan every 2 weeks
- elective c section 37
- EmCS/earlier if bleeding
What are the complications of placenta praevia
Antepartum haemorrhage
Postpartum haemorrhage