Maternal Medicine

Question 1

Be able to demonstrate a detailed understanding of the issues relating to pregnancy complicated by diabetes mellitus.

Answer 1

• Foetal abnormalities
  
  • 5mg folic acid supplementation from preconception until 12 weeks gestation
  • Pre-conception HbA1c target of 48mmol/L
• Use of medications
  
  • Insulin and/or metformin can be used prior to conception and during pregnancy
  • Medications for co-morbidities should also be reviewed e.g. ACEis and statins
• Development/progression of retinopathy
  
  • Screening at booking and at 28 weeks gestation
  • Other diabetic complications should also be monitored for (nephropathy, neuropathy, hypertension, thryroid disease)
• Increased risk of pre-eclampsia
  
  • 75mg aspirin to be taken from 12 weeks gestation
  • Increased monitoring of maternal BP and proteinuria
• Increased risk of foetal macrosomia or IUGR
  
  • ​Regular growth scans arranged for monitoring
• Increased risk of stillbirth as gestation progresses
  
  • Planned delivery between 37 and 38 + 6 weeks (before 39 weeks)
• Control of maternal blood glucose levels during labour
  
  • Sliding scale insulin regime is considered for mothers with T1DM during labour
• Neonatal complications
  
  • Hypoglycaemia, polycythaemia, jaundice, congenital heart disease and cardiomyopathy

Question 2

Be able to demonstrate some knowledge and experience in the diagnosis and management of pregnancy complicated by obesity.

Answer 2

Obesity in pregnancy is defined as BMI of 30 kg/m² or higher at the first antenatal consultation.

Management

Pre-conception

• 5-10% weight loss can be enough to improve health during pregnancy
• Ideal BMI is 18.5 - 24.9 kg/m²
• A reduction in BMI can increase the chance of conceiving
• 5mg folic acid

During pregnancy

• Reducing risk of foetal macrosomia:
  
  • Weight gain during pregnancy expected to be less than those of ‘normal’ weight, 7 - 11.5kg for overweight and 5-9kg for obese (compared to 11.5-16kg)
  • Dispel ‘eating for 2’ myth. No need to increase calorific intake until 6 months, ~ 200 cals/day is sufficient
• 5mg folic acid and 10 micrograms vitamin D supplementation until 12 weeks gestation
• Management of increased VTE risk
  
  • BMI > 30 kg/h² → VTE assessment at booking
  • > 3 risk factors → LMWH should be prescribed and continued until 6/52 following delivery
• Management of increased risk of pre-eclampsia
  
  • ​75mg aspirin throughout pregnancy
• Management of increased risk of GDM
  
  • OGTT between 24 - 28 weeks
• Loss of SFH accuracy in obese patients
  
  • Serial growth US scans are instead performed from 28 weeks

During Labour

• BMI > 35 kg/h² → delivery in an obs, rather than midwife led, unit
• FSE may be required to allow improved foetal monitoring, as CTG is often difficult

​After Delivery

• Ongoing VTE prophylaxis as indicated
• 6/52 check of fasting glucose for those with GDM

Question 3

Be able to demonstrate some knowledge and experience in the diagnosis and management of pregnancy complicated by thrombophilia.

Answer 3

Diagnosis: Antenatal assessment of VTE risk should be performed.

Management *dependent on level of risk for VTE development*

Previous VTE assoicated with antithrombin deficiency → Higher dose LMWH

NOTE - Dehydration is a risk factor for VTE, hence patients with hyperemesis gravidarum and OHSS should be provided with LMWH, providing that delivery is not imminent

Question 4

Be able to demonstrate some knowledge and experience in the diagnosis and management of pregnancy complicated by pre-existing hypertension.

Answer 4

Diagnosis:

BP of > 140/90 mmHg at booking OR within the first 20 weeks of pregnancy.²

• If new, look to exclude secondary causes of hypertension e.g. CoA, renal artery stenosis, Cushing syndrome etc.

*** BP > 160/110 mmHg in pregnancy is a medical emergency

Management

• Increased risk of pre-eclampsia, foetal growth restriction and placental abruption.
• Cessation of inappropriate anti-hypertensives (increased risk of congential abnormalities)
  
  • ​ACEis, ARBs, thiazide diuretics should be changed to labetalol or methyldopa
  • Aim for 135/85 mmHg
• Increased risk of developing pre-eclampsia
  
  • 75-150 mmHg of aspirin from conception
• Monitoring for foetal growth restriction
  
  • US every 4/52 from 28 weeks gestation
  • Umbilical artery doppler, amniotic fluid volume assessment and foetal growth should be assessed
• Monitor BP hourly through labour (or continuously if >160/100)
• Oxytocin ONLY¹ at the 3rd stage of labour
• Post-natal medications
  
  • Methyldopa should be changed to another hypertensive after delivery (risk of postnatal depression)
  • Diuretics should be avoided if breast feeding

1: Syntometrine (ergometrine + oxytocin) causes severe hypertension, increasing the risk of stroke
2: New onset hypertension occurring in the second half of pregnancy is gestational hypertension.

Question 5

Be able to demonstrate some knowledge and experience in the diagnosis and management of pregnancy complicated by epilepsy.

Answer 5

Diagnosis: 2 or more seizures 24 hours apart, or a single seizure characteristic of an epilepsy sydrome.

Management:

• Pre-conceptual advice
  
  • ​Aim to be seizure free for at least 2/12 before conception
  • 5mg folic acid, continued until 12 weeks gestation
  • Lifestyle advice to minimise risk if a seizure should occur: avoid swimming, shower instead of bath, ensure adequate sleep and the effects of vomiting on AEDs
• AED use in pregnancy
  
  • Monotherapy is often safer
  • Lamotrigine and carbamazepine are regarded as the safest drug choices in pregnancy
  • Adjusting AED levels to compensate for changes seen in pregnancy
  • Sodium valporate and lamotrigine levels should be monitored in pregnancy (each trimester)
• Increased risk of foetal malformations (neural tube defects, cleft lips/palates, heart defects)
  
  • Detailed cardiac USS offered at 16 weeks, or as part of the anomaly scan
• Labour carries the highest risk of seizures
  
  • Avoid pethidine, as it lowers the seizure threshold
  • Continuous CTG monitoring is required
  • Ensure good hydration and pain relief

Question 6

Be able to demonstrate an awareness of the issues involved in the diagnosis and management of pregnancy complicated by HIV.

Answer 6

Diagnosis:

Screening is performed at the booking appointment (plus syphilis and HBV).

Management:

• Viral load monitoring
  
  • Viral load and CD4 should also be established in HIV positive mothers.
  • Viral load monitoring should be performed each trimester, at 36 weeks and around the time of delivery
• Reducing risk of transmission to the foetus
  
  • ​Pre-conceptual optimisation of ART (combination therapy of at least 3 antiretroviral drugs)
  • Decide mode of delivery by 36 weeks (elective C-section if viral load is high)
  • Neonate commenced on ART once born, continued for at least 4/52
  • Advise against breastfeeding, due to risk of transmission
• ​Screen for other STIs and other opportunistic infections
  
  • ​HBV, HCV, varicella, syphilis, rubella, measles and toxoplasmosis

Question 7

Be able to demonstrate an awareness of the issues involved in the diagnosis and management of pregnancy complicated by of cardiac disease.

Answer 7

Diagnosis

• Symptoms indicative of cardiac disease include syncope, dyspnoea, fatigue, orthopnoea, chest pain and palpitations. Raised JVP and oedema may be seen
• Raised RR, tachycardia and orthopnoea are important symptoms which require investigation
• Arrhythmias and heart failure are the most common complications to arise during pregnancy. MI and valvular problems may also arise.

Management

• Regular review in joint obstetric and cardiology clinic
  
  • Review symptoms
  • Investigations (e.g. ECHO) to monitor disease progression
• Discuss timing and mode of delivery
  
  • Note that pushing in the 2nd phase of labour is particularly stressing on the CV system, hence C-section may be considered a safer option
  • Must give birth in hospital; have epidural, continuous CTG and abx
• Postnatal follow-up is essential

Specific cases

Peripartum cardiomyopathy: Heart dilates and weakens during pregnancy, inducing heart failure symptoms (fatigue, SOB and fluid retention).

Hypertrophic obstructive cardiomyopathy: Increasingly diagnosed in pregnant women. An adult onset condition associated with a FHx

Question 8

Be able to demonstrate an awareness of the issues involved in the diagnosis and management of pregnancy complicated by other chronic maternal conditions.

Answer 8

Hypothyroidism

• Untreated or under-treated hypothyroidism can leads to miscarriage, anaemia, SGA and pre-eclampsia
  
  • ​As the foetal thyroid gland does not develop fully until 16 weeks gestation the foetus relies on maternal thyroid hormone prior to this
• Levothyroxine is safe for use during pregnancy and can cross the placenta

Rheumatoid arthritis

• Ideally, symptoms should be well controlled for at least 3/12 before pregnancy
• Symptoms often improve during pregnancy and then flare following delivery
• Medication choice during pregnancy
  
  • ​Methotrexate is contraindicated *teratogenic - miscarriage and congenital abnormalities*
  • Hydroxychloroquine is considered safe (often 1st line)
  • Sulfasalazine is considered pregnancy