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Medical Complications of Pregnancy - Key Study Notes (pp. 148-157)

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1. RENAL DISEASE IN PREGNANCY (pp. 148-149)

CKD Classification

• Stages 1-2 affect ~3% of women aged 20-39; stages 3-5 affect 1 in 150

Effect of Pregnancy on CKD

• Stages 1-2: Usually uneventful if creatinine <110 µmol/L, proteinuria <1 g/24h, BP controlled - little long-term harm
• Stages 3-5: Highest risk of complications + accelerated renal decline
• Pre-eclampsia is difficult to diagnose (pre-existing HTN/proteinuria)
• NSAIDs, postpartum haemorrhage, and pre-eclampsia can critically threaten renal function

Prepregnancy Counselling Topics

• Safe contraception, fertility issues, genetic counselling
• Avoid teratogens and contraindicated drugs
• BP treatment, low-dose aspirin, anticoagulation (if significant proteinuria)
• Warn about: strict surveillance, early delivery, accelerated renal decline

CKD Monitoring in Pregnancy

• BP, creatinine, urine (infection + proteinuria), FBC (Hb + ferritin)
• Renal and fetal ultrasound; uterine artery Doppler at 20-24 weeks

Estimated Effects of Renal Function on Outcome (Table 10.2)

Dialysis in Pregnancy (Stage 5 CKD)

• Haemodialysis > peritoneal dialysis
• Complications: preterm delivery, polyhydramnios (30-60%), pre-eclampsia (40-80%), caesarean delivery (50%)

Renal Transplant Pregnancy

• Fertility returns rapidly post-transplant; 2-10% of female recipients conceive
• Advise conception after 2nd post-transplantation year with stable graft

• 90% of pregnancies beyond 1st trimester succeed

• All are high-risk - multidisciplinary team mandatory
• Risk of acute rejection in pregnancy ~2%
• Tacrolimus, azathioprine, ciclosporin, prednisolone: generally safe; mycophenolate and sirolimus - avoid
• Vaginal delivery is safe; small risk to transplant with caesarean

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2. DIABETES MELLITUS IN PREGNANCY (pp. 150-152)

Prepregnancy Counselling

• Target HbA1c <42 mmol/mol before conception (without hypoglycaemia)
• High-dose folic acid 5 mg/day (neural tube defect risk reduction)
• Stop statins and ACE inhibitors pre-pregnancy
• Poor glycaemic control → congenital anomalies (especially neural tube and cardiac defects); most critical period = first 42 days
• HbA1c >85 mmol/mol → fetal loss risk ~30%
• Women with retinopathy, nephropathy, neuropathy → multidisciplinary review before pregnancy

Maternal and Fetal Complications (Type 1 & 2)

• Congenital abnormality 2-4x more common (3x excess cardiac + neural tube defects)
• Fetal macrosomia → shoulder dystocia, traumatic birth
• Stillbirth 5x higher than general population, especially 3rd trimester
• Pre-eclampsia risk 3x higher, especially with microvascular disease
• All women with diabetes: low-dose aspirin from 12 weeks
• Retinopathy can progress; screen at booking, 16-20 weeks, 28 weeks
• Other risks: infection, severe hypoglycaemia/hyperglycaemia, DKA, high operative delivery rate

Management of Type 1 & 2 in Pregnancy

• Multidisciplinary team (diabetic midwives, dietitian, obstetrician, physician)
• Blood glucose monitoring 7 times/day (before and 1hr after meals)
• Targets: pre-meal <5.3 mmol/L; 1-hour postprandial <7.8 mmol/L
• Insulin resistance increases in 2nd half → increase insulin/metformin dose
• If corticosteroids given → extra insulin needed
• Fetal anomaly scan at 19-20 weeks (includes cardiac outflow tracts)
• Serial growth scans to monitor macrosomia/polyhydramnios
• Delivery target: vaginal, 38-39 weeks (if uncomplicated)
• Caesarean section rate ~50% in diabetic women
• In labour: sliding scale insulin; keep glucose 4-7 mmol/L
• Insulin requirements drop immediately post-delivery; risk of hypoglycaemia postnatal (esp. if breastfeeding)

Effects of Pregnancy on Diabetes

• Nausea/vomiting → poor early glucose control
• Increased insulin needs in 2nd half of pregnancy
• Increased severe hypoglycaemia risk
• Risk of deterioration in retinopathy and nephropathy

Effects of Diabetes on Pregnancy (Summary Box)

• Miscarriage, congenital malformation, macrosomia, pre-eclampsia, stillbirth, infection, operative delivery

Gestational Diabetes (GDM)

• Affects 10-15% of pregnancies
• GDM women have increased risk of type 2 diabetes later in life
• Diagnosis by glucose tolerance test (GTT)

• Glucose targets in GDM: pre-meal <5.3 mmol/L; 1hr post-meal <7.8 mmol/L
• If diet/lifestyle fails → metformin and/or insulin
• Postpartum: fasting glucose or HbA1c at 6-13 weeks after birth (exclude type 2 DM)

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3. THYROID DISEASE (pp. 152-153)

Physiology in Pregnancy

• Pregnancy symptoms overlap with thyroid disease (fatigue, weight gain, palpitations)
• Use free T4 (fT4), free T3 (fT3), TSH - NOT total T3 or T4
• 1st trimester: TSH falls, fT4 rises; then fT4 falls as gestation advances

Hypothyroidism

• ~1% of pregnant women
• Most common cause in developed world = Hashimoto's thyroiditis
• Continue thyroid replacement therapy; aim for biochemical euthyroidism (TSH <4 mmol/L)
• TFTs every trimester (or more often if dose adjusted)
• Maternal T4 is critical in 1st trimester (fetal thyroid not active yet)
• Suboptimal treatment → developmental delay + pregnancy loss

Hyperthyroidism (Graves' Disease)

• ~2 per 1,000 pregnancies
• Treatment: carbimazole or PTU (lowest acceptable dose - high doses cross placenta → fetal hypothyroidism)
• Both cause agranulocytosis → regular maternal WBC monitoring
• Radioactive iodine is absolutely contraindicated (obliterates fetal thyroid)
• Beta-blockers: initial use only, until antithyroid drugs take effect
• Thyroid surgery: rare, only for tracheal compression, malignancy suspicion, or failed medical therapy
• Uncontrolled thyrotoxicosis → miscarriage, preterm delivery, FGR
• Many women reduce/stop medication in pregnancy (thyroid function improves)

Graves' Disease - Fetal Risk

• TSH receptor stimulating antibodies cross placenta
• Risk of fetal Graves' disease after 20 weeks - proportional to antibody level
• Babies born to antibody-positive mothers → neonatal team review

Thyroid Storm

• Life-threatening; fatal in 20-50% if untreated
• Triggered by undertreatment or infection; can mimic eclampsia
• Features: sweating, pyrexia, tachycardia, AF, hypertension, hyperglycaemia, cardiac failure
• Treatment: PTU + high-dose corticosteroids + beta-blockers + rehydration

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4. OTHER ENDOCRINE CONDITIONS (p. 153-154)

Parathyroid Disease

• Hyperparathyroidism: elevated PTH → hypercalcaemia; ideally surgical removal before pregnancy; mild cases managed with hydration + low-calcium diet; fetal risks include miscarriage, intrauterine death, preterm labour, neonatal tetany
• Hypoparathyroidism: low calcium + low PTH; usually post-thyroid surgery; treat with vitamin D + oral calcium

Pituitary Tumours (Prolactinoma)

• Hyperprolactinaemia → infertility + amenorrhoea; most often benign microadenoma
• Treated with dopamine agonist (bromocriptine or cabergoline) in 80%
• Stop bromocriptine/cabergoline in pregnancy (usually safe); monitor visual fields
• If tumour growth signs → restart dopamine agonist + neuroimaging
• Pituitary gland enlarges 50% in pregnancy; rare for microadenomas to cause problems
• Macroadenomas (>1 cm): continue dopamine agonist due to risk of enlargement

Cushing's Syndrome

• Rare in pregnancy (most affected women are infertile)
• In pregnancy, adrenal causes (tumours) are more common than pituitary
• High incidence of pre-eclampsia, preterm delivery, stillbirth

Conn's Syndrome

• Adrenal tumour → excess aldosterone → secondary hypertension + hypokalaemia

Addison's Disease (Adrenal Insufficiency)

• Autoimmune; diagnosis difficult (cortisol levels may be in low-normal range due to increased cortisol-binding globulin)
• Continue glucocorticoid replacement; increase at times of stress (hyperemesis, delivery)

Phaeochromocytoma

• Rare (1 in 50,000 pregnancies); catecholamine-secreting tumour
• Presents as hypertensive crisis mimicking pre-eclampsia; characteristic feature = paroxysmal hypertension
• Diagnose via 24-hour urine catecholamines + plasma catecholamines + adrenal imaging
• Treatment: alpha-blockade (prazosin/phenoxybenzamine) + beta-blocker (propranolol/atenolol)
• Caesarean section preferred to avoid catecholamine surges with vaginal delivery
• Maternal and perinatal mortality greatly increased if not diagnosed before pregnancy

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5. HEART DISEASE IN PREGNANCY (pp. 155-157)

Prepregnancy Counselling Topics

• Risk of maternal death, reduced life expectancy
• Effects of pregnancy on cardiac disease
• Mortality with high-risk conditions
• Risk of fetal congenital heart disease
• Preterm labour, FGR, frequent hospital admission
• Surgical correction should be done before pregnancy if needed

NYHA Classification (Table 10.3)

Toronto Risk Score for Cardiac Events (Table 10.4)

1. Prior episode of heart failure, arrhythmia, or stroke
2. NYHA Class >II or cyanosis
3. Left heart obstruction
4. Reduced LV function (EF <40%)

• 0 predictors → 5% risk; 1 predictor → 37%; >1 predictors → 75% risk

Antenatal Management

• Manage in a joint obstetric/cardiac clinic
• Ask about breathlessness at night, change in heart rate/rhythm, reduced exercise tolerance
• Routine exam: pulse, BP, JVP, heart sounds, ankle/sacral oedema, basal crepitations
• Echocardiogram at booking and ~28 weeks

High-Risk Cardiac Conditions

• Systemic ventricular dysfunction (EF <30%, NYHA III-IV)
• Pulmonary hypertension
• Cyanotic congenital heart disease
• Aortic pathology (dilated aortic root >4 cm, Marfan syndrome)
• Ischaemic heart disease
• Left heart obstructive lesions (aortic/mitral stenosis)
• Prosthetic heart valves (metal)
• Previous peripartum cardiomyopathy

Fetal Risks from Maternal Cardiac Disease

• Recurrence of congenital heart disease, maternal cyanosis (fetal hypoxia), iatrogenic prematurity, FGR, teratogenic drug effects

Anticoagulation

• Warfarin: teratogenic in 1st trimester; risk of fetal intracranial haemorrhage in 3rd trimester
• LMWH preferred, especially in 1st and 3rd trimesters; titrate with anti-Xa levels
• Essential in: pulmonary hypertension, atrial fibrillation risk, metal valve replacements

Labour Management in Heart Disease

• Avoid induction if possible; aim for spontaneous labour
• Use prophylactic antibiotics (structural heart defect → endocarditis risk)
• Avoid supine position; ensure fluid balance
• Epidural anaesthesia recommended (reduces pain-related cardiac demand)
• Keep second stage short - elective forceps/ventouse if normal delivery not occurring
• Caesarean only if maternal condition too unstable for labour
• Use Syntocinon slowly with low-dose infusion (not ergometrine - causes intense vasoconstriction)
• High-level monitoring until haemodynamic changes post-delivery resolve

Treatment of Heart Failure in Pregnancy

• Same principles as non-pregnant: diuretics, vasodilators, digoxin
• Oxygen and morphine may be required
• Arrhythmias: urgent drug correction (e.g., adenosine for SVT)
• Assess fetal wellbeing with ultrasound + CTG
• If fetal compromise → consider premature delivery

Risk Factors for Heart Failure in Pregnancy

Ischaemic Heart Disease

• MI risk in pregnancy ~1 in 10-15,000; peak in 3rd trimester; >40 years, parous women
• Primary cause = coronary artery dissection (not atherosclerosis)
• PTCA acceptable but avoid during 8-15 weeks (fetal radiation susceptibility)

Mitral Stenosis

• Usually rheumatic origin; 40% worsen in pregnancy (average onset of pulmonary oedema at 30 weeks)
• Aim to reduce heart rate: bed rest, oxygen, beta-blockade, diuretics
• Balloon mitral valvotomy: treatment of choice - can be done in pregnancy if needed
• Maternal mortality 2%; fetal risk related to severity

Aortic Stenosis

• Well-tolerated if mild-moderate with normal exercise capacity
• Severe AS: maternal mortality 17%, fetal mortality 30%
• Reduce heart rate to allow ventricular filling
• If deteriorating: balloon or surgical aortic valvotomy possible

Marfan Syndrome

• Autosomal dominant connective tissue disorder → risk of mitral/aortic abnormalities (continued on next page)

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• CKD stages 3-5 = worst outcomes (remember: more creatinine = more complications)
• HbA1c <42 before conception; folic acid 5 mg; aspirin from 12 weeks in diabetes
• GDM targets: <5.3 pre-meal, <7.8 post-meal
• Radioactive iodine = absolutely contraindicated in pregnancy
• Warfarin = dangerous in 1st & 3rd trimesters; use LMWH
• Phaeochromocytoma = Caesarean section preferred
• Thyroid storm = PTU + steroids + beta-blockers

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Medical Complications of Pregnancy - COMPLETE Study Notes (pp. 148-161)

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1. RENAL DISEASE IN PREGNANCY (pp. 148-149)

CKD Classification

• Stages 1-2 affect ~3% of women aged 20-39; stages 3-5 affect 1 in 150

Effect of Pregnancy on CKD

• Stages 1-2: Usually uneventful if creatinine <110 µmol/L, proteinuria <1 g/24h, BP controlled - little long-term harm
• Stages 3-5: Highest risk of complications + accelerated renal decline
• Pre-eclampsia is difficult to diagnose (pre-existing HTN/proteinuria)
• NSAIDs, postpartum haemorrhage, and pre-eclampsia can critically threaten renal function

Prepregnancy Counselling Topics

• Safe contraception, fertility issues, genetic counselling
• Avoid teratogens and contraindicated drugs
• BP treatment, low-dose aspirin, anticoagulation (if significant proteinuria)
• Warn about: strict surveillance, early delivery, accelerated renal decline

CKD Monitoring in Pregnancy

• BP, creatinine, urine (infection + proteinuria), FBC (Hb + ferritin)
• Renal and fetal ultrasound; uterine artery Doppler at 20-24 weeks

Estimated Effects of Renal Function on Outcome (Table 10.2)

Dialysis in Pregnancy (Stage 5 CKD)

• Haemodialysis > peritoneal dialysis
• Complications: preterm delivery, polyhydramnios (30-60%), pre-eclampsia (40-80%), caesarean delivery (50%)

Renal Transplant Pregnancy

• Fertility returns rapidly post-transplant; 2-10% of female recipients conceive
• Advise conception after 2nd post-transplantation year with stable graft

• 90% of pregnancies beyond 1st trimester succeed

• All are high-risk - multidisciplinary team mandatory
• Risk of acute rejection in pregnancy ~2%
• Tacrolimus, azathioprine, ciclosporin, prednisolone: generally safe; mycophenolate and sirolimus - avoid
• Vaginal delivery is safe; small risk to transplant with caesarean

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2. DIABETES MELLITUS IN PREGNANCY (pp. 150-152)

Prepregnancy Counselling

• Target HbA1c <42 mmol/mol before conception (without hypoglycaemia)
• High-dose folic acid 5 mg/day (neural tube defect risk reduction)
• Stop statins and ACE inhibitors pre-pregnancy
• Poor glycaemic control → congenital anomalies (especially neural tube and cardiac defects); most critical period = first 42 days
• HbA1c >85 mmol/mol → fetal loss risk ~30%
• Women with retinopathy, nephropathy, neuropathy → multidisciplinary review before pregnancy

Maternal and Fetal Complications (Type 1 & 2)

• Congenital abnormality 2-4x more common (3x excess cardiac + neural tube defects)
• Fetal macrosomia → shoulder dystocia, traumatic birth
• Stillbirth 5x higher than general population, especially 3rd trimester
• Pre-eclampsia risk 3x higher, especially with microvascular disease
• All women with diabetes: low-dose aspirin from 12 weeks
• Retinopathy can progress; screen at booking, 16-20 weeks, 28 weeks
• Other risks: infection, severe hypoglycaemia/hyperglycaemia, DKA, high operative delivery rate

Management of Type 1 & 2 in Pregnancy

• Multidisciplinary team (diabetic midwives, dietitian, obstetrician, physician)
• Blood glucose monitoring 7 times/day (before and 1hr after meals)
• Targets: pre-meal <5.3 mmol/L; 1-hour postprandial <7.8 mmol/L
• Insulin resistance increases in 2nd half → increase insulin/metformin dose
• If corticosteroids given → extra insulin needed
• Fetal anomaly scan at 19-20 weeks (includes cardiac outflow tracts)
• Serial growth scans to monitor macrosomia/polyhydramnios
• Delivery target: vaginal, 38-39 weeks (if uncomplicated)
• Caesarean section rate ~50% in diabetic women
• In labour: sliding scale insulin; keep glucose 4-7 mmol/L
• Insulin requirements drop immediately post-delivery; risk of hypoglycaemia postnatal (esp. if breastfeeding)

Effects of Pregnancy on Diabetes

• Nausea/vomiting → poor early glucose control
• Increased insulin needs in 2nd half of pregnancy
• Increased severe hypoglycaemia risk
• Risk of deterioration in retinopathy and nephropathy

Effects of Diabetes on Pregnancy

• Miscarriage, congenital malformation, macrosomia, pre-eclampsia, stillbirth, infection, operative delivery

Gestational Diabetes (GDM)

• Affects 10-15% of pregnancies; GDM → increased risk of type 2 DM later in life
• Diagnosed by glucose tolerance test (GTT)

• Glucose targets in GDM: pre-meal <5.3 mmol/L; 1hr post-meal <7.8 mmol/L
• If diet/lifestyle fails → metformin and/or insulin
• Postpartum: fasting glucose or HbA1c at 6-13 weeks after birth (exclude type 2 DM)

Factors Associated with Poor Outcome in Diabetes

• Social deprivation, no prepregnancy folic acid, suboptimal glycaemic control at any stage, suboptimal preconception/maternity care, suboptimal surveillance of big babies

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3. THYROID DISEASE (pp. 152-153)

Physiology in Pregnancy

• Use free T4 (fT4), free T3 (fT3), TSH - NOT total T3 or T4
• 1st trimester: TSH falls, fT4 rises; then fT4 falls as gestation advances

Hypothyroidism

• ~1% of pregnant women; most common cause = Hashimoto's thyroiditis
• Continue thyroid replacement; aim TSH <4 mmol/L (biochemical euthyroidism)
• TFTs every trimester (or more often if dose adjusted)
• Maternal T4 critical in 1st trimester (fetal thyroid not yet active)
• Suboptimal treatment → developmental delay + pregnancy loss

Hyperthyroidism (Graves' Disease)

• ~2 per 1,000 pregnancies
• Treatment: carbimazole or PTU (lowest acceptable dose)
• High doses cross placenta → fetal hypothyroidism
• Both drugs cause agranulocytosis → regular WBC monitoring
• Radioactive iodine = absolutely contraindicated (obliterates fetal thyroid)
• Beta-blockers: initial use only until antithyroid drugs take effect
• Thyroid surgery: rare (only tracheal compression, malignancy, failed medical therapy)
• Uncontrolled thyrotoxicosis → miscarriage, preterm delivery, FGR
• Many women reduce/stop medication (thyroid function often improves in pregnancy)
• TSH receptor antibodies cross placenta → risk of fetal Graves' disease after 20 weeks

Thyroid Storm

• Fatal in 20-50% if untreated; triggered by undertreatment or infection; can mimic eclampsia
• Features: sweating, pyrexia, tachycardia, AF, hypertension, hyperglycaemia, cardiac failure
• Treatment: PTU + high-dose corticosteroids + beta-blockers + rehydration

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4. OTHER ENDOCRINE CONDITIONS (pp. 153-154)

Parathyroid Disease

• Hyperparathyroidism: elevated PTH → hypercalcaemia; surgical removal ideal before pregnancy; fetal risks: miscarriage, intrauterine death, preterm labour, neonatal tetany
• Hypoparathyroidism: usually post-thyroid surgery; treat with vitamin D + oral calcium

Pituitary Tumours (Prolactinoma)

• Most often benign microadenoma; treated with bromocriptine or cabergoline (80% shrink)
• Stop dopamine agonist in pregnancy usually; monitor visual fields + symptoms
• Macroadenomas (>1 cm): continue dopamine agonist (risk of enlargement under oestrogen)
• Pituitary enlarges 50% in pregnancy

Cushing's Syndrome

• Rare (most affected women infertile); in pregnancy adrenal tumours more common than pituitary
• High incidence of pre-eclampsia, preterm delivery, stillbirth

Conn's Syndrome

• Adrenal tumour → excess aldosterone → secondary hypertension + hypokalaemia

Addison's Disease

• Continue glucocorticoid replacement; increase dose at times of stress (hyperemesis, delivery)

Phaeochromocytoma

• 1 in 50,000 pregnancies; paroxysmal hypertension mimicking pre-eclampsia
• Diagnose: 24-hour urine catecholamines + plasma catecholamines + adrenal imaging
• Treatment: alpha-blockade (prazosin/phenoxybenzamine) + beta-blocker
• Caesarean section preferred (avoid catecholamine surge with vaginal delivery)
• High maternal and perinatal mortality if undiagnosed before pregnancy

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5. HEART DISEASE IN PREGNANCY (pp. 155-158)

Prepregnancy Counselling Topics

• Risk of maternal death, reduced life expectancy, effects of pregnancy on cardiac disease
• Risk of fetal congenital heart disease; preterm labour, FGR
• Surgical correction should be done before pregnancy if needed

NYHA Classification

Toronto Risk Score for Cardiac Events

1. Prior heart failure, arrhythmia, or stroke
2. NYHA Class >II or cyanosis
3. Left heart obstruction
4. Reduced LV function (EF <40%)

• 0 predictors → 5% risk; 1 predictor → 37%; >1 predictors → 75%

Antenatal Management

• Manage in joint obstetric/cardiac clinic
• Echocardiogram at booking and ~28 weeks
• Routine exam: pulse, BP, JVP, heart sounds, ankle/sacral oedema, basal crepitations

High-Risk Cardiac Conditions

• Systemic ventricular dysfunction (EF <30%, NYHA III-IV)
• Pulmonary hypertension, cyanotic congenital heart disease
• Aortic pathology (root >4 cm, Marfan syndrome)
• Ischaemic heart disease, left heart obstructive lesions, prosthetic metal valves
• Previous peripartum cardiomyopathy

Anticoagulation

• Warfarin: teratogenic in 1st trimester; fetal intracranial haemorrhage risk in 3rd trimester
• LMWH preferred especially in 1st and 3rd trimesters; titrate with anti-Xa levels

Labour Management in Heart Disease

• Avoid induction if possible; aim for spontaneous labour
• Prophylactic antibiotics (structural heart defect → endocarditis risk)
• Avoid supine position; ensure fluid balance
• Epidural anaesthesia recommended (reduces cardiac demand)
• Keep second stage short - assisted delivery (forceps/ventouse) if needed
• Caesarean only if too unstable for labour
• Syntocinon slowly (low-dose infusion) - NOT ergometrine (ergometrine causes intense vasoconstriction + heart failure risk)

Treatment of Heart Failure in Pregnancy

• Same as non-pregnant: diuretics, vasodilators, digoxin; oxygen + morphine if needed
• Arrhythmias: urgent correction (e.g., adenosine for SVT)

Risk Factors for Heart Failure in Pregnancy

Ischaemic Heart Disease / MI in Pregnancy

• Risk ~1 in 10-15,000; peak in 3rd trimester; primary cause = coronary artery dissection (not atherosclerosis)
• PTCA acceptable; avoid 8-15 weeks (fetal radiation risk)

Mitral Stenosis

• Usually rheumatic; 40% worsen in pregnancy; pulmonary oedema average onset at 30 weeks
• Aim to reduce heart rate: bed rest, oxygen, beta-blockade, diuretics
• Balloon mitral valvotomy = treatment of choice (can be done in pregnancy)
• Maternal mortality 2%

Aortic Stenosis

• Mild-moderate: usually well-tolerated
• Severe AS: maternal mortality 17%, fetal mortality 30%
• Aim to reduce heart rate for ventricular filling; surgical valvotomy if deteriorating

★ Marfan Syndrome (NEW - p.158)

• Autosomal dominant connective tissue disorder
• Risks: mitral valve prolapse, aortic regurgitation, aortic root dilatation, aortic rupture/dissection
• Pregnancy increases risk of aortic rupture/dissection
• Maternal mortality up to 50% where there is marked aortic root dilatation
• Echocardiography is the key investigation - assess aortic root size; serial echo throughout pregnancy
• Aortic root >4 cm = high risk
• Aortic root <4 cm → risk of adverse cardiac event ~1% (reassuring)
• Obstetric complications: early pregnancy loss, preterm labour, cervical weakness, uterine inversion, postpartum haemorrhage

★ Pulmonary Hypertension (NEW - p.158)

• One of the highest-risk cardiac conditions in pregnancy
• Maternal mortality remains very high
• (Included in high-risk conditions list above)

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6. NEUROLOGICAL DISORDERS (pp. 160-161)

★ Epilepsy (NEW)

• ~30% of those with epilepsy are women in childbearing years; 1 in 200-250 pregnancies
• Pregnancy has no consistent effect on seizure frequency (some improve, some worsen, some same)
• 10-fold increase in maternal mortality in women with epilepsy; 1 in 20 indirect maternal deaths
• Principle: risks from seizures outweigh risks from anticonvulsants
• Seizures should be controlled with minimum dose of optimal drug

Prepregnancy Counselling in Epilepsy

• Alter medication according to seizure frequency
• Reduce to monotherapy where possible
• Stress importance of compliance
• Preconceptional folic acid 5 mg
• Explain risk of congenital malformation
• Explain risk from recurrent seizures
• If seizure-free for 2 years → consideration may be given to discontinuing medication prepregnancy

Teratogenicity of Anticonvulsants

• All AEDs associated with 2-3 fold increased risk of fetal abnormality (5-6% vs baseline)
• Women with epilepsy NOT taking AEDs do NOT have increased fetal risk
• Polytherapy increases risk of major congenital abnormality by ~3% per additional AED
• Major fetal abnormalities associated with AEDs:
  • Sodium valproate, carbamazepine, phenytoin, phenobarbitone → neural tube defects, facial clefts, cardiac defects
  • Valproate specifically → dose-dependent (>1,000 mg/day); fetal valproate syndrome: developmental delay, nail hypoplasia, growth restriction, midface abnormalities
  • Valproate should be avoided in pregnant women except when epilepsy cannot be controlled otherwise
• All women should be offered detailed anomaly scanning
• Continuing anticonvulsants despite risks is usually correct (uncontrolled seizures → maternal and fetal hypoxia)

Managing AEDs in Pregnancy

• Drug levels fall in pregnancy (altered metabolism, sleep deprivation, stress, poor compliance)
• Monitoring drug levels is difficult (not always reliable guide)
• Increasing dose to prevent falls may increase fetal risk
• If no increase in seizure frequency → prenatal drug dosage can usually be continued
• Lamotrigine levels fall rapidly in pregnancy → often needs dose increase
• Delivery mode largely unaltered by epilepsy unless there has been accelerated seizure frequency
• Continue anticonvulsant medication during labour
• Breastfeeding encouraged but avoid feeding for a few hours after taking medication
• Information on safe handling of neonate should be given to all epileptic mothers

Causes of Seizures in Pregnancy (Differential Diagnosis)

• Epilepsy
• Eclampsia
• Encephalitis or meningitis
• Space-occupying lesion (tumour, tuberculoma)
• Cerebral vascular accident
• Cerebral malaria or toxoplasmosis
• Thrombotic thrombocytopaenic purpura (TTP)
• Drug and alcohol withdrawal
• Toxic overdose
• Metabolic abnormalities (e.g., hypoglycaemia)

★ Multiple Sclerosis (NEW)

• Relapsing-remitting disease; demyelination → weakness, lack of coordination, numbness, blurred vision, tremor, spasticity, voiding dysfunction
• More common in women; 1 in 1,000 pregnancies
• Onset of MS in pregnancy is unusual; optic neuritis is predominant initial symptom
• Effect of pregnancy on MS:
  • Lower relapse rate during pregnancy
  • Relapse rate rises significantly in first 3 months postpartum
  • Pregnancy may be associated with lower risk of progression long-term
  • No increased risk of preterm delivery, FGR, or congenital malformations
• Disease-modifying drugs (DMDs): number has increased over last 15 years; first-line treatment should be started where appropriate (experience in pregnancy still limited - use cautiously)

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QUICK-REFERENCE SUMMARY