O&G JC110: I Am Pregnant: Medical Problems Complicating Pregnancy Flashcards
Medical conditions during pregnancy
- Co-incidental / Pre-existing
- DM, renal disease, HT, autoimmune diseases, cardiac diseases (e.g. congenital heart diseases), asthma - Arising as a result of pregnancy
- **hyperemesis gravidarum, **gestational HT, **GDM, **acute fatty liver of pregnancy, acute renal failure / DIC secondary to obstetrics complications e.g. post-partum haemorrhage - Pregnancy ↑ risk of some medical disorders / aggravate them
- **Fe-deficiency anaemia, **thromboembolism
Medical conditions related to pregnancy
- HT
- DM
- Thyroid disease
- Autoimmune disease
- Cardiac conditions
- Epilepsy
- Venous thromboembolism
- Liver disease
- Hypertension in pregnancy
Pre-existing:
- Hypertension: High BP <20 weeks
- Renal disease: Proteinuria <20 weeks (after exclusion of UTI)
Gestational:
- Normal BP <20 weeks, High BP first detected >20 weeks
- HT without proteinuria
- HT with proteinuria —> ***Pre-eclampsia
Pre-existing HT with superimposed Pre-eclampsia
- Pre-existing HT —> Develop proteinuria >20 weeks
Management:
- Irrespective of cause of HT —> severe HT should be controlled to prevent **intracerebral haemorrhage
- Most Anti-HT can be used **except ACE-I
- Pre-clamptic patients more sensitive to **Vasodilators —> need to use **smaller doses than in non-pregnant patients
- Rapid lowering of BP may **↓ uterine perfusion —> **Fetal hypoxia
Other management during pregnancy:
1. MgSO4
- prevention of eclampsia
2. Investigations
- CBP
- LRFT
- Coagulation tests
3. Monitor fetal wellbeing when she is stable
4. Consider delivery of baby when woman is stable
- Diabetes mellitus in pregnancy
Effect of pregnancy on pre-existing DM
1. Blood glucose more difficult to control
- **fasting hypoglycaemia (可以低)
- **antagonising effect of placental hormones on insulin (可以高)
2. ↑ Stress on CVS / Renal system
3. Progression of diabetic retinopathy
Effect of pre-existing DM on pregnancy
Maternal:
1. ↑ Risk of complications
- **Pre-eclampsia
- **UTI
- ***Preterm labour
2. ↑ Incidence of C-section / Instrumental delivery
Fetal:
1. ↑ Risk of **congenital malformations
- neural tube
- skeletal
- cardiac
- renal
- GI
2. **Preterm delivery
3. **Large-for-gestational age (LGA)
4. Metabolic complications
5. Sepsis
6. **Jaundice —> phototherapy
7. Respiratory complications e.g. RDS
8. ***Asphyxia / Birth trauma
9. Long-term consequences on offspring
- Fetal programming effect on metabolic / CVS diseases (i.e. higher chance of developing these diseases in the future)
Management:
1. Starts before pregnancy
- good glycaemic control before pregnancy
- hyperglycaemia is ***teratogenic
- incidence of major congenital abnormality directly proportional to HbA1c level
- During pregnancy
- tight glycaemic control
—> diet but extra caloric intake needed to cover baby’s need
- oral hypoglycaemic drugs are **not CI but tight glycaemic control more difficult to achieve
- **insulin usually needed —> adjust insulin dosage on day-to-day basis
- monitor for maternal / fetal complications —> ***fetal USG to check on fetal growth + exclude congenital abnormalities - Labour
- may need labour induction before due date
- tight blood glucose control using **insulin-dextrose drip + **K replacement (∵ insulin cause inward shift of K) - After delivery
- regular blood glucose monitoring by dextrostix of baby for ***hypoglycaemia (∵ extra insulin made by baby during pregnancy)
Summary:
1. Pre-pregnancy counselling important
2. Prenatal diagnosis where necessary
3. **Monitor fetal growth + wellbeing
4. Monitor development of pregnancy complications
5. Timing of delivery
6. **Tight glycaemic control during intra-partum period
7. Neonatal assessment
8. ***Post-partum monitoring of hypoglycaemia / jaundice + treatment
9. Multi-disciplinary approach
- obstetrician, endocrinologist, DM nurse, dietitian, neonatologist
Gestational DM
- Women not diabetic but become diabetic during pregnancy / DM first detected during pregnancy
- She and baby faces similar problems but usually to milder degree than pre-existing DM
- Management similar
—> Good glycaemic control by Diet + Insulin
- Thyroid disease in pregnancy
- Transient biochemical hyperthyroidism
- No clinical features of thyrotoxicosis
- can occur in early pregnancy esp. in women with hyperemesis gravidarum - Thyroid disease esp. **Autoimmune thyroiditis occur more frequently in **post-partum period
- Thyroxine has ***no known adverse effect on pregnancy (i.e. can be used in pregnancy) unless clinically hyperthyroid
- Subclinical hypothyroidism (high TSH, normal fT4)
- associated with **preterm labour, ↑ incidence of delayed neurological development in offsprings (observational data only)
—> may need to give thyroxine to **↓ TSH level - Hyperthyroidism
- RAI (radioactive iodine) **CI in pregnancy
- Propylthiouracil (PTU) / Carbimazole commonly used
—> no known teratogenicity
—> PTU: cross less through placenta, risk of liver failure
—> both can theoretically cause **neonatal hypothyroidism (usually reversible) - Graves’ disease
- AutoAb can cause ***neonatal hyperthyroidism (rare and reversible)
- Autoimmune diseases in pregnancy
Effect of pregnancy on autoimmune diseases:
1. Pregnancy is associated with changes in immune system
—> lower risk of flare due to immunosuppressive status during pregnancy (except SLE) (SpC Revision)
—> some autoimmune diseases may worsen (e.g. SLE) / improve during pregnancy (e.g. RA)
- Pregnancy may further **stress end organ / system affected by autoimmune disease e.g. **Kidney
- In general pregnancy is **CI during acute flare up of disease
- advise pregnancy **only when during remission which is safest
Effect of autoimmune diseases on pregnancy:
1. AutoAb can cross placenta and affect baby / placental function
- **Fetal thrombocytopenia in maternal ITP (Immune thrombocytopenic purpura)
- **Congenital heart block induced by maternal **Anti-Ro Ab
- **Neonatal lupus
- IUGR and Pregnancy loss by maternal **Lupus anticoagulant
- **Anti-cardiolipin Ab (a type of Anti-mitochondrial antibody)
- End organ / system disease can adversely affect pregnancy
- Autoimmune thyroiditis —> **hypothyroidism —> abnormal fetal neurological development
- Renal problem / HT —> **IUGR + ↑ prevalence of superimposed **pre-eclampsia
- ITP —> maternal thrombocytopenia —> excessive **bleeding during delivery
Effect of treatment of autoimmune diseases on pregnancy:
1. Steroids (generally safe)
- IUGR
- Fetal cleft lip (small risk)
- Adrenal insufficiency (SpC Revision)
- Cerebral atrophy
- Use Prednisolone over Dexamethasone (cross more over placenta)
- Immunosuppressants (potentially teratogenic)
- ***Azathioprine relatively safe - Cytotoxic drugs (potentially teratogenic)
- **MTX: toxic to pregnancy, cause pregnancy loss —> **absolutely CI in pregnancy
Management:
1. Control with **steroid
2. Check AutoAb e.g. **Anti-Ro, **Lupus anticoagulant, **Anti-cardiolipin
3. Prepare for small - moderate risk of pre-eclampsia, IUGR, pregnancy loss
4. Joint management by rheumatologist and obstetrician during pregnancy
- Cardiac conditions in pregnancy
Effect of Pregnancy on Cardiac conditions:
1. ***Heart failure
- can occur during pregnancy even though cardiac disease is well-compensated before pregnancy
- ∵ Physiological ↑ in CO in pregnancy —> additional strain to heart
- Antenatal anaemia —> worsen heart failure
- Drug use in pregnancy —> β-adrenergics tocolytics for arresting pre-term labour can precipitate heart failure
- ↑ Stress + Physical demand during labour / delivery
- Excessive IV fluids —> worsen heart failure
- Post-partum period: ***Volume overload
- ∵ ↓ Uterine blood volume —> Blood return to systemic circulation —> ↑ effective circulatory volume —> Volume overload
- Precipitate heart failure (often RH)
- ↑ R to L shunt esp. in presence of Pulmonary hypertension
Effect of Cardiac conditions on Pregnancy:
1. **Growth of fetus (Smaller fetal size) + more frequent **Preterm labour
- Normal physiological ↑ in CO limited by cardiac conditions
- Hypoxia in cyanotic heart disease —> affect growth of fetus
Effective of Treatment of cardiac conditions on Pregnancy:
1. **Diuretics
- limit normal physiological volume expansion during pregnancy —> **IUGR
- Warfarin
- ↑ risk of congenital abnormalities (**Warfarin embryopathy) (esp. 1st trimester)
- ↑ fetal loss (if baby develop **intracranial haemorrhage) - ACE-I
- **↑ fetal loss
- cause **oligohydramios
- ***↓ fetal renal perfusion - Atenolol (SpC Revision)
- ***IUGR
Effective of Pregnancy on Treatment of cardiac conditions:
1. ***Teratogenic drugs
- may need to be substituted before pregnancy / in 1st trimester
- PK changes in pregnancy affect ***serum level of drugs
- Digoxin, Warfarin
- careful readjustment of dosage may be needed - Other forms of treatment carry high risks to mother / baby
- Cardiac catheterisation (X-ray exposure)
- Open heart surgery (Hypotension, Hypothermia, Hypoxia)
—> consider postpone?
Other considerations:
1. ***Antibiotic prophylaxis for mechanical heart valves / grossly damaged valves (but not for most other cases)
- Prevention of bacterial endocarditis during delivery
- ***Thromboembolism prevention
- e.g. AF secondary to MS —> consider Anticoagulation - Time + Mode of delivery
- multidisciplinary support
- in general: spontaneous onset of labour, vaginal delivery +/- epidural analgesia carries lowest risk (but need to be individualised) (epidural analgesia can potentially ↓ systemic BP)
- Epilepsy in pregnancy
Anti-epileptics (many) are **teratogenic
- cleft lip + palate, neural tube defect
- if epilepsy cannot be controlled without drugs —> do NOT stop drugs —> consider **monotherapy if possible
- **Folic acid supplement (higher dose) ↓ incidence of congenital abnormalities associated with anti-epileptics
- detailed prenatal **USG examination to assess fetal abnormality
***Folate supplement before 12 weeks
- 0.4 mg/day (Felix Lai)
- 5 mg/day: previous infant with neural tube defect, DM patients, patients on anti-epileptic drugs (Felix)
- 5 mg/day throughout whole pregnancy: Thalassaemia trait (to prevent maternal anaemia)
- Venous thromboembolism in pregnancy
↑ Thromboembolism risk in pregnancy
- Virchow’s triad all present
- Immobility
- ***Hypercoagulability (↑ in pregnancy, further ↑ in post-partum period, blood viscosity ↑ in hyperemesis)
- Obstruction to blood flow / venous return by Gravid uterus
Assessment of risk:
Pre-existing:
1. Demographic (advanced age, obesity, ethnicity)
2. Smoking
3. Congenital / Acquired thrombophilia
4. Family history of thromboembolism
Current:
1. Pregnancy / Treatment-related
- pregnancy a ***pro-coagulation state
- pre-eclampsia (∵ contracted IV volume due to edema—> thromboembolism)
- hyperemesis (∵ ↑ blood viscosity —> thromboembolism)
- bed rest
- C-section, post-partum genital tract infection
- Concurrent to pregnancy
- infection, immobilisation due to injury, long haul flights
Management:
1. Prevention of thromboembolism in pregnancy
- **Minimise immobility
—> do NOT prescribe bed rest for threatened miscarriage, IUGR, conditions where not proven to be effective (e.g. preterm labour)
- **Adequate hydration
- ***Special stockings
- Medical prevention considered in high risk cases
- **LMWH / Heparin in antenatal / postnatal period (may consider Warfarin in postnatal period)
—> Warfarin: **teratogenic: avoid in 1st / 3rd trimester
- Women on long-term anticoagulants before pregnancy should be ***continued on anticoagulants during pregnancy —> consider changing from Warfarin to LMWH / Heparin in 1st trimester + after 36 weeks
- Women at ↑ risk of thromboembolism during pregnancy and post-partum should receive **prophylactic anticoagulant
—> Cover for high risk episode (e.g. 10 days after C-section following **pre-eclampsia / during immobilisation)
—> Cover for 6 weeks post-partum for high risk (e.g. **previous DVT)
—> Cover throughout pregnancy + 6 week post-partum (if very very high risk e.g. **Antiphospholipid syndrome (APLS), ***previous PE)
Strategies of Anticoagulant use in pregnancy to prevent thromboembolism
- Anticoagulants carry risks, injudicious use can kill!!!
- Thromboembolism can also kill
—> Risk stratification important
LMWH:
- relatively safe but needs injection
- use in antenatal period / for short use in postnatal period
Warfarin:
- taken orally but cross placenta
- **teratogenic: avoid in 1st / 3rd trimester
- use in postnatal period if longer treatment (weeks) needed
- **safe for breast feeding
- long t1/2: consider changing to LMWH in 3rd trimester (∵ difficult to reverse anticoagulant effect during labour)
- Liver disease in pregnancy
Causes:
1. Concurrent (i.e. unrelated to pregnancy)
- Due to pregnancy
- **Deranged LFT in pre-eclampsia
- **Acute fatty liver of pregnancy
- ***Cholestasis of pregnancy - Liver failure related to pregnancy
- ***Reactivation of HBV (∵ altered immune status, stress of post-partum period, use of herbals)
Summary
- Obstetrics conditions can mimic medical conditions
—> pre-eclampsia mimicking hypertensive encephalopathy - Women with chronic medical diseases can get pregnant
—> pre-pregnancy counselling, make sure disease condition is in remission, contraceptive advice, careful use of drugs in women in reproductive age group - Effects of pregnancy on pre-existing medical disease / its treatment
- Effects of medical disease / its treatment on pregnancy
- Consider both mother + baby
- Prevalence of some medical diseases ↑ during pregnancy / post-partum period e.g. **VTE, **autoimmune diseases
Maternal obesity (SpC Revision)
Effect on pregnancy:
1. Difficult fetal assessment e.g. size of uterus
- P/E
- USG (poorer image quality)
- Maternal complications
- DM / GDM
- HT / Pre-eclampsia - Anaesthesia challenge
- Difficult setting up regional anaesthesia
- Difficult airway in GA
- OSA
Effect on mother during pregnancy:
1. Increase body weight
2. Compromise cardiopulmonary reserve
Maternal drug use
Physiological haemodilution (∵ expansion of plasma volume)
- Decrease serum level of medication
—> Decrease therapeutic effect (e.g. control of epilepsy)
—> Need increase in dosage + regular monitoring of drug level
