Antenatal Care and Screening

Question 1

Risk factors in pregnancy

Answer 1

• Age
  
  • Teenagers more at risk of social deprivation, lack of support, smoke more and may not receive antenatal care
  • Older women (especially over 40), more prone to pre-existing medical condition, chromosomal disorders
• Parity
  
  • Pre-eclampsia most commonly occurs in nulliparity (first pregnancy)
  • Post-partum haemorrhage in grand multiparity (4 or more deliveries)
• Occupation
  
  • Jobs which expose mother and foetus to risk
  • Busy jobs with inadequate rest
  • Exposure to harmful substances causing foetal anomalies
• Substance misuse
  
  • Heroine, methadone, benzodiazepines are addictive to foetus
  • Requires slow withdrawal post borsht

Question 2

Alcohol in pregnancy

Answer 2

• Can cause foetal abnormalities → foetal alcohol syndrome
• Distinctive facial features and learning difficulties

Question 3

Obesity in pregnancy

Answer 3

• Higher rates of poor outcomes e.g. miscarriage and stillbirth
• Difficulty monitoring fundal height for foetal growth
• VTE much more common

Question 4

Pre-pregnancy counselling

Answer 4

• Ideally for all women however ⅓ of pregnancies are unplanned
• Especially for women with previous health or pregnancy problems
• e.g obesity and alcoholism
• Predominately done in primary care
• Involves
  
  • General health measures: improving diet, optimise BMI, reduced alcohol intake
  • Smoking cessation
  • Folic acid requirements
  • Confirm immunity to rubella

Question 5

Gastrointestinal changes in pregnancy

Answer 5

• Reduced oesophageal peristalsis
• Slowed gastric emptying
• Relaxed cardiac sphincter (LOS)
• Reduced GI motility (increased progesterone and decreased motilin)

Question 6

Respiratory changes in pregnancy

Answer 6

• Pregnancy causes physiological respiratory alkalosis due to progesterone acting on central respiratory centres
  
  • Increased tidal volume
  • Increased respiratory rate
  • Increased plasma PH
• O2 consumption increased
• Plasma PO2 unchanged

Question 7

Anaemia in pregnancy

Answer 7

• Increased plasma volume and RBC mass → drop in haemoglobin dilution
• Iron requirements in pregnancy increase by 1g
• Iron supplements required at checkup if ferritin below 110 at 28 weeks

Question 8

Increased risk of UTI’s in pregnancy

Answer 8

• Increased urinary stasis → easier path for ascending infection → pyelonephritis
• Physiological hydronephrosis in trimester III → pyelonephritis
• Increased incidence of pre-term labour (MSSU and antibiotics more indicated)

Question 9

Cardiac problems

Answer 9

• Palpitations
  
  • Increase in cardiac output
• Drop in blood pressure in second trimester
  
  • Expanded uteroplacental circulation
  • Fall in systemic vascular resistance
  • Reduced blood viscosity
  • Reduced sensitivity to angiotensin

Question 10

Hyperemesis gravidarum

Answer 10

• Much worst than morning sickness
• Presentation
  
  • Prolonged and severe nausea
  • Dehydration (unable to keep fluids down)
  • Ketosis → build up of acidic chemicals in blood and urine
  • Weight loss
  • Low blood pressure
• May not get better after 16 weeks

Question 11

Morning sickness

Answer 11

• Affects majority of pregnant women
• Worse with conditions of high hGH (twins, molar pregnancy
• Can progress to hyperemesis gravidarum
• Usually gets better by 16 weeks

Question 12

Pregnancy problems considered in pre-pregnancy counselling

Answer 12

• Foetal

Question 13

Second trimester scan

Answer 13

• Recommended around 20 weeks
• Purpose to detect foetal anomalies
• Poor test for structural abnormalities

Question 14

Anecephaly

Answer 14

• Neural tube defect causing failure of skull vault to develop
• Brain matter unprotected and is worn away
• Incompatible with extrauterine life

Question 15

First scan visit

Answer 15

• Approximately at 12 weeks
• Functions
  
  • Ensure pregnancy is viable
  • Multiple pregnancies
  • Identify anomalies incompatible with life → anencephalic foetus
  • Establish crown rump length
  • Offer screening for Down’s syndrome
  • Diagnose miscarriage
  • Diagnose ectopic pregnancy
  • Examine maternal ovaries

Question 16

Function of the ultrasound scan in pregnancy

Answer 16

• Viewing morphology of the pregnancy against checklist of normal views
• Show the first signs of pregnancy
  
  • Thickened lining of the womb
  • 4.5 weeks → fluid filled intrauterine sac
  • 5 weeks → yolk sac within uterus
  • 6 weeks → foetal heart pulsation

Question 17

Isoimmunisation

Answer 17

• Development of antibodies against particular blood groups
• Commonly rhesus disease (anti-d antibodies)
  
  • Occurs with woman is rhesus negative and carries rhesus positive baby
  • Anti-D antibodies develop if foetal blood cells enter maternal circulation (miscarriage, termination, ectopic pregnancy)
  • Higher risk of in subsequent pregnancies
• Offered anti D IbG to all rhesus negative women prophylactically after sensitising event

Question 18

What forms part of the antenatal screening

Answer 18

• Hepatitis B → provide active or passive immunisation for baby
• Syphilis → causes intrauterine growth restriction, hepato-splenomegaly, anaemia, thrombocytopenia, skin rashes, treated with penicillin
• HIV screening → use ARV and avoidance of breast feeding to reduce vertical spread
• Iron deficiency anaemia → iron tablets
• Isoimmunisation → development of antibodies against blood groups

Question 19

Function of antenatal screening

Answer 19

• Testing symptomless population to detect disease in early stages for better outcomes
• Not compulsory and requires adequate counselling before
• Allows conditions to be treated in mother and foetus in early stages

Question 20

External cephalic version (ECV)

Answer 20

• Manual procedure where baby is turned from buttocks/ foot to head first
• Normally offered if baby remains breech after 36 weeks
• If this doesn’t work, baby usually delivered by elective caesarean (safer outcomes)
• Listen to foetal heart

Question 21

Purpose of abdominal palpation

Answer 21

• Determine the lie of the baby
• Certain lies more associated with poor outcomes during delivery → ie. placenta praaevia
• Foetal lies
  
  • Longitudinal lie
  • Transverse lie
  • Breech
  • Vertex

Question 22

Ante-natal examination

Answer 22

• Routine questions (feeling well, foetal movements after 20 weeks)
• Blood pressure (hypertension and urinalysis)
• Abdominal palpitation (symphysial fundal height, size of baby, liquor volume)

Question 23

Indication for a caesarean

Answer 23

• If a patient has had a previous Caesarean section
• Only if she has had one for a non-recurring cause (breech position)
• Customary to delivery by elective caesarean after 2 previous caesarean

Question 24

Previous pregnancy problems to counsel regarding the recurrence of

Answer 24

• Mother
  
  • Caesarean section
  • DVT → thromboprophylaxis
  • Pre-eclampsia → low dose aspirin
• Foetus
  
  • Pre-term labour → treatment of infection
  • Intrauterine growth restriction
  • Foetal abnormality → foetal abnormality
    *

Question 25

Existing health conditions and pregnancy

Answer 25

• Phenyketonuria (PKU)
  
  • Inability to metabolise phenylalanine causing high levels
  • Causes mental developmental impairments
  • Mother with PKU requires low phenylalanine diet to prevent it reaching foetus
• Hypothyroidism
  
  • Increased metabolic demand in pregnancy
  • Increased demand of thyroxine especially for foetal brain development
  • Increased dosage required
• Hyperthyroidism
  
  • Small percentage with Graves disease
  • Thyroid stimulating antibodies can cross placenta
  • Requires treatment to lower thyroid levels
• Pre-existing diables
  
  • Optimised glucose control
  • Switch from oral hypoglycaemic medications to insulin
  • Higher risk of preeclampsia, stillbirth, macrosomic infants
• Renal patients
  
  • Higher risk of pre-eclampsia especially with pre-existing proteinuria and hypertension
  • Renal transplant indicated
• Epilepsy
  
  • Anti-epileptic medications → teratogenic
  • Higher rates of spina bifida with sodium valproate
• Ideally women would not take any medications during pregnancy