Antenatal Care Flashcards
Purpose of Antenatal Care
aims to provide Evidence-based Information and Support to make informed
decisions, Advise on Minor problems and symptoms, Assess Maternal and Foetal Risk, Monitor Wellbeing throughout pregnancy
• BP and Urine check at every visit to detect signs of Pre-eclampsia and Diabetes
What is shared obstetric care
GP and Community Midwife undertake most Obstetric care, with limited number of visits to Hospital
o Routine Involvement of Obstetrician in care of Uncomplicated Pregnancy does not improve Perinatal Outcomes
o Information given regarding giving birth at home, at Midwife-led unit, or Hospital
What happens at first contact?
Folic acid and Lifestyle advice, Antenatal Screening and Booking Appointment
When should booking happen?
Booking should happen ideally early in pregnancy (<12/40); Very late bookers, or unbooked pregnancies have higher risk of Perinatal and Maternal Morbidity and Mortality
What happens at booking?
should comprise Comprehensive History and Full Physical Examination
o BMI, BP, Dipstick, Ultrasound for Gestational age
o Information on Antenatal Classes, Pregnancy Care Pathway, Nutrition, Diet, Vitamins, Maternity Benefits and information on Foetal development
Blood Tests at Pregnancy: FBC
Lower limit of normal Hb at 10.5; Commonest cause of Anaemia is IDA
o Investigate Haematinics (Ferritin, TIBC, Red Cell Folate, Serum B12)
Blood Tests at Pregnancy: Blood group and abnormal antibodies
If Rh negative with Rh positive father – Commence Anti D Prophylaxis
Blood Tests at Pregnancy: Syphilis
Uncommon but important cause of Neonatal Disease
Blood Tests at Pregnancy: Rubella
2% of Nulliparous and 1% of multiparous are non-immune to Rubella; Should
receive Post-Partum Rubella vaccination
Blood Tests at Pregnancy: Hep B
Neonates infected are at higher risk of becoming Chronic Carriers
(90%), and higher risk of developing Cirrhosis and HCC
o Neonates given Hep B Vaccination at birth if mother HBsAg positive but e negative; If e positive, +Passive Immunisation (HBIg)
Blood Tests at Pregnancy: HIV
Vertical Transmission can be reduced by two thirds if treatment of mother
with Antiretrovirals, and Neonate for 6/52 post; Risk of transmission reduced with C-section and avoidance of Breastfeeding
Blood Tests at Pregnancy: Haemoglobinopathies
Hb Electrophoresis – Minor Ethnic or Racial origins with high risk of Haemoglobinopathies
(Mediterranean, Middle Eastern, Indian, SEA for Thalassaemia, African/Afro-Caribbean for
Sickle Cell disease); Also, if Persistent Maternal Anaemia
Blood Tests at Pregnancy: Others
Thyroid, HbA1c, Baseline Urea and Creatinine
16 week appointment
(Discuss Screening, investigate if Hb<11g/dL, Arrange Anomaly scan at 18-20 weeks)
25 weeks
if Primiparous – BP, Urine Drip, SFH plot (The works)
28 weeks
Screen Anaemia and Atypical RBC allo-ab, Anti D Prophylaxis, BP, The works
31 weeks
The works
34 weeks
Discuss Labour and Birth, Anti D Prophylaxis, The works
36 weeks
Discuss Breastfeeding, Vit K Prophylaxis, Post-natal care, Mental Health awareness, The works
Other antenatal appointments in third trimester
38, 40, 41 weeks: membrane sweep, 42 weeks: induction
Prenatal Screening Tests
Prenatal Diagnosis helps in Planning Timing, Mode and Place of Delivery, Preparation for Parents, Planning Specialist Neonatal Services, Foetal Surveillance, In-Utero Treatment and
option of Termination of Pregnancy
Screening for chromosomal abnormalities
Negative result doesn’t guarantee no abnormality
Offered to all women at booking
Combined Test
For Down Syndrome Offered at 11-13 weeks Nuchal scan: Increased translucency marker for structural defects PAPP-A B-HCG
How is Down Syndrome risk calculated?
Down syndrome risk = Maternal Age Risk × Gestation-related risk (NT + Blood tests)
o Foetuses with Downs more likely to have absent/hypoplasia Nasal bone, Significant
Tricuspid Regurgitation
Alternative screening for Down’s Syndrome
Dating scan plus Triple/Quad Tests at 16/52
– Oestriol, hCG, AFP, and inhibin A
o Oestriol reduced in Trisomy 21 and 18; hCG reduced in T18 and raised in T21
o Recommended if NT scan was not possible, or
missed window for Combined test
Other trisomy screening
Integrated Test (NT and PAPP-A at 10 – 13 weeks, Quad serum at 15 weeks) and
Serum Integrated Test (Dating Scan, PAPP-A at 10 weeks, Quad serum at 15 weeks)
• AFP – If above 2.2 multiples of median, screening for Open NTDs and other structural defects
e.g. Abdominal Wall, Nephrosis, Bowel Obstruction, Teratomas etc
o Marker of Adverse Perinatal Outcomes – Foetal death, IUGR, Late Bleeding and Prem
Screening for structural abnormalities
Occurs at 18 – 21 weeks Gestation; High pickup rate of CNS but lower of Cardiac defects
• Covers Skull Shape and Internal Structures, Spine, Abdominal Shape and Contents, Arms,
Legs, Heart, Face and Lips
Neural Tube Defects
Occur early in development due to failure of closure; Believed to be reduced due to Folate supplementation; Spinal Bifida and Anencephaly make up 95% of defects
o Anencephaly – Absence of Skull vault and Cortex; Incompatible with life
o Spinal Bifida – Occulta, Meningocoele, Myelomeningocoele
Cardiac Defects
Most common major malformations; May be associated with Chromosomal
abnormalities (Commonly T21 and 18); Most common is VSD
o Risk Factors – FH, Maternal Rx (Li, AEDs), Maternal DM, Other congenital
abnormalities, Increased NT
Renal Agenesis
Lethal due to Anhydramnios causing Lung Hypoplasia; May not be evident
before 16/40 as Amniotic fluid not fully urinary before then
Posterior Urethral Valve Syndrome
(Males, Outflow Obstruction), Hydronephrosis (75% of
Renal Abnormalities; May be PUJ obstruction, VUR, Ureterocoele, PUV)
Lung Hypoplasia
Often Oligohydroamnios; Also, Compression; Severity associated with PPROM<25/40, Severe Oligohydramnios, Early delivery; High Mortality
Diaphragmatic Hernia
30% incidence of Aneuploidy; 40% Postnatal death from Lung
Hypoplasia; Others might require Postnatal Surgery; Foetal surgical techniques in
development e.g. Foetoscopic Tracheal Occlusion
Congenital Cystic Adenomatoid Malformation
Rare; Normal lung replaced by Proliferation of
Cysts resembling Bronchioles
Exomphalos (Omphacocele)
Failure of gut to return to Abdominal Cavity after normal Extrusion and Rotation; Viscera contained within sac, and Umbilical cord arises from apex
o 1/3 occur with Chromosomal abnormalities; another 1/3 have other malformations
o Prognosis depends on Karyotype, Concurrent malformations, Ischaemia; 40% Mort
Gastroschisis
Protrusion of gut through Anterior Abdominal wall defect (usually Right of Umbilicus);
Not covered by sac
o Usually occurs in very young mothers (<25yrs); No increased risk of
Chromosomal Abnormalities; 5 – 10% may die In-Utero or post-natal, but prognosis is
good in the remainder of infants
Gastrointestinal Obstruction
Duodenal Atresia
(30% T21), Oesophageal Atresia (15% have Aneuploidy), Other Atresias may occur with Syndromes or Gastroschisis
Chorionic Villus Sampling
Performed 10-13/40; Aspiration of some Trophoblastic cells
Small amount of tissue taken Transabdominally (sometimes Transcervical) under USS
guidance for Karyotyping; Rapid analysis is possible with FISH and PCR
Chorionic Villus Sampling: Indication
Indications include Karyotyping in first trimester if screening indicates high risk for Aneuploidy, and DNA analysis of parents of carriers of identifiable gene mutation
Chorionic Villus Sampling: Risk
Allows for first trimester TOP
risk of Miscarriage 1%; Increased risk of
Vertical transmission of Blood-borne Viruses
Chorionic Villus Sampling: Accuracy
Placental Mosaicism and Maternal contamination can cause misleading results
Amniocentesis
Performed >15/40; Aspiration of Amniotic fluid, which contains shed Foetal
cells from skin and GI tract; Transabdominal under USS guidance
Amniocentesis: Indications
Same indications as CVS, plus allow for Enzyme assay for IEMs; Can also be used to
diagnose Foetal Infections e.g. CMV, Toxoplasmosis
Amniocentesis: Risk
Lower procedure-attributed risk vs. CVS; Lower risk of Maternal contamination, or
Placental Mosaicism
