Maternal Diseases ✅ Flashcards
Give 3 categories of maternal diseases that can affect a fetus?
- Diabetes mellitus
- Red blood cell alloimmunisation
- Immune mediated disease
What is maternal diabetes mellitus associated with?
Increased perinatal morbidity and mortality
How can perinatal morbidity and mortality due to maternal diabetes mellitus be reduced?
Good blood glucose control from pre-conception
What fetal problems are associated with maternal diabetes mellitus?
- Congenital malformations
- Sudden intrauterine death
- Macrosomia
- Intrauterine growth restriction
- Preterm labour
- Hypoglycaemia
- Hyperbilirubinaemia
- Respiratory distress syndrome
- Hypertrophic cardiomyopathy
- Polycythemia
By how much is the risk of congenital malformations increased with maternal diabetes mellitus?
4x
What congenital malformations in particular is there an increased risk of with maternal diabetes mellitus?
- Cardiac malformations
- Caudal regression syndrome (sarcral agenesis)
When does maternal diabetes mellitus the risk of sudden intrauterine death?
In the third trimester
What is macrosomia defined as?
LGA >90th centile
What causes macrosomia in maternal diabetes mellitus?
Maternal hyperglycaemia results in glucose crossing the placenta, which causes fetal hyperinsulinaemia, which promotes growth
How does the % of infants with a birthweight of >4kg compare between diabetic and non-diabetic mothers?
Up to 25% in diabetic mothers, compared to 8% in non-diabetic mothers
What complications are macrocosmic infants at higher risk of?
Cephalopelvic disproportion causing;
- Obstructed labour
- Shoulder dystocia
- Birth trauma
How much is the risk of IUGR increased in diabetic mothers?
3x
What is the increased risk of IUGR in diabetic mothers associated with?
Maternal microvascular disease
What is the risk of preterm labour in diabetic mothers?
10% (either spontaneous or induced)
When is induction of labour usually planned in diabetic mothers?
38weeks
What are the neonatal problems associated with maternal diabetes mellitus?
- Hypoglycaemia
- Hyperbilirubinaemia
- Respiratory distress syndrome
- Hypertrophic cardiomyopathy
- Polycythaemia
When is hypoglycaemia common in infants born to diabetic mothers?
First 48 hours after birth
Why is hypoglycaemia common in the first 48 hours of life for infants born to diabetic mothers?
Due to residual hyperinsulinism
What is hypoglycaemia often accompanied by in neonates born to diabetic mothers?
- Hypocalcaemia
- Hypomagnesaemia
What can hyperbilirubinaemia in a child born to a diabetic mother be exacerbated by?
Polycythaemia
Why are infants born to diabetic mothers at a higher risk of respiratory distress syndrome?
Due to delayed maturation of surfactant
Is hypertrophic cardiomyopathy common in infants born to diabetic mothers?
No, is uncommon
What causes hypertrophic cardiomyopathy in infants born to diabetic mothers?
From fetal hyperinsulinism
What might hypertrophic cardiomyopathy cause in infants born to diabetic mothers?
Transient outflow obstruction
What causes polycythaemia in infants born to diabetic mothers?
Chronic fetal hypoxia
What does neonatal polycythaemia increase the risk of?
- Stroke
- Seizures
- Necrotising enterocolitis
- Renal vein thrombosis
What happens in maternal red blood cell alloimmunisation?
Maternal antibody is formed to fetal red blood cell antigens
What fetal red blood cell antigens might maternal antibody be produced against?
- Rhesus D
- Anti-Kell
- Anti-c
Give an example of a disease caused by maternal red blood cell alloimmunisation
Rhesus haemolytic disease
What has happened to the incidence of rhesus haemolytic disease?
It has reduced
Why has the incidence of rhesus haemolytic disease reduced?
Due to the introduction of anti-D prophylaxis
What kind of antibodies can cross the placenta?
IgG
Why can IgG cross the placenta?
Because they are small molecules
What is the importance of IgG transfer across the placenta?
It confers passive immunity to the infant
What it the problem with IgG transfer across the placenta?
When maternal IgG is part of a disease state, transplacental passage may result in damage to the fetal tissues or cause transient disease in the infant
Give 5 examples of maternal immune mediated diseases that can affect a foetus?
- Hyperthyroidism (Grave’s disease)
- Hypothyroidism
- Autoimmune thrombocytopenia
- SLE
- Myasthenia
When is a fetus/infant rarely affected by maternal hyperthyroidism?
If the mother is on treatment
What can happen in foetuses of mothers with untreated hyperthyroidism?
Transient neonatal thyrotoxicosis
What causes transient neonatal thyrotoxicosis?
Transplacental transfer of TSH receptor antibodies (TRAbs)
How does transient neonatal thyrotoxicosis present?
Tachycardia and features of neonatal hyperthyroidism
How long does transient neonatal thyrotoxicosis need treatment for?
Several months
What might occur in infants of mothers who are on anti-thyroid drug therapy?
Transient hypothyroidism
Can maternal hypothyroidism cause problems in the neonate if it is treated?
It is rare
What is the global importance of maternal hypothyroidism?
It is an important cause of congenital hypothyroidism secondary to maternal iodine deficiency
How can maternal autoimmune thrombocytopenia affect the foetus?
Antiplatelet IgG autoantibodies in maternal thrombocytopenia can cross the placenta causing fetal thrombocytopenia
Does maternal immune mediated fetal thrombocytopenia always require treatment?
No, rarely does
What can maternal immune mediated fetal thrombocytopenia cause if severe?
Cerebral haemorrhage before birth or from birth trauma
What is required in severe cases of maternal immune mediated fetal thrombocytopenia?
Intrauterine IV platelet transfusions
What should be given if there is severe thrombocytopenia or petechiae at birth in maternal immune mediated fetal thrombocytopenia?
IV immunoglobulins
When will IV platelets be given in the neonatal period for maternal immune mediated thrombocytopenia?
Only for extremely low platelet counts or active bleeding
Why are IV platelets only given in the neonatal period for maternal immune mediated thrombocytopenia if there is extremely low platelet counts or active bleeding?
Because of the anti platelet antibodies
How can maternal SLE affect pregnancy?
- Increased risk of recurrent miscarriage
- Increased chance of congenital heart block
Why are mothers with SLE at increased risk of recurrent miscarriage?
Due to vasculopathy associated with SLE
What is the chance of a mother with SLE having a baby with congenital heart block?
0.5-2%
Why is there an increased chance of complete heart block in babies of mothers with SLE?
Due to the presence of anti-Ro and anti-La autoantibodies, which may damage the conduction system in the fetal heart
What may be needed in babies with congenital heart block?
Pacemaker insertion
How can maternal myasthenia affect the foetus?
Maternal acetylcholine receptor (AChR) IgG antibodies can cross the placenta
What is it produced when maternal AChR IgG cross the placenta?
Transient neonatal myasthenia
How does transient neonatal myasthenia present?
Hypotonia after delivery, causing problems with feeding and sometimes respiration
How is transient neonatal myasthenia diagnosed?
Administration of anti-cholinesterase (neostigmine)
What happens when neostigmine is given in transient neonatal myasthenia?
Rapid improvement
How long does transient neonatal myasthenia last for?
2 months
In what situation can perinatal alloimmune thrombocytopenia develop?
When fetal platelets contain an antigen which the mother lacks
What are the most common antigens implicated in perinatal alloimmune thrombocytopenia?
HPA-1a or 5b
What is the pathological process in perinatal alloimmune thrombocytopenia?
The mother develops antibodies which cross the placenta and bind to fetal platelets
What is perinatal alloimmune thrombocytopenia analogous to?
Rhesus D alloimmunisation
In what respects does perinatal alloimmune thrombocytopenia differ from rhesus D alloimmunisation?
- Often affects first pregnancy
- Maternal antiplatelet antibody titres are not predictive of severity of the fetal thrombocytopenia
What can be done if perinatal alloimmune thrombocytopenia is identified from a previously affected infant?
Can be treated with IVIG and platelets if necessary
How is severe thrombocytopenia after birth treated in perinatal alloimmune thrombocytopenia?
Platelet transfusions negative for the platelet antigen
