Obstetric Flashcards
Haem
During a normal pregnancy blood count changes may occur in blood count changes for which cells?
Mild anaemia (diluational anaemia) - Red cell mass increases - Plasma volume increases (more than the rbc mass) Macrocytosis - may cause folate and B12 deficiency Neutrophilia Thrombocytopenia - increase in platelet size due to increased turnover
Iron requirement increases during pregnancy Why does this happen?
300mg for fetus 500mg for maternal increased red cell mass RDA 30mg Increase in daily iron absorption 1-2mg to 6mg
Iron requirement increases during pregnancy What may iron deficiency cause?
IUGR Low birth weight Premature heart defects
Iron requirement increases during pregnancy What iron and folate supplements in pregnancy are suggested?
60mg iron and 400ug folic acid during pregnancy
Anaemia in pregnancy definition?
What is thrombocytopenia in pregnancy defined as?
Platelet cound falls in pregnancy - 175-199 non pregnant - 225-249
Causes of thrombocytopenia in pregnancy? (4)
Physiological gestational fall - primary pre-eclampsia (HELLP - haemolysis, elevated liver, low platelets) Immune thrombocytopenia ITP - slightly more common in pregnancy but can occur anytime MAHA syndromes (microangiopathic syndromes) others : BM failure, hypersplenism, DIC, leukaemia
How much thrombocytopenia is acceptable for delivery?
> 50x10^9
How much thrombocytopenia is acceptable for epidural delivery?
> 70x10^9 >50 usually for normal delivery
if thrombocytopenia is more severe (<70x10^9) is it more likely to be normal gestational or pathological?
More likely to be pathological e.g. ITP or pre-eclampsia
What happens to thrombocytopenia after delivery for each following condition? Gestational thrombocytopenia Preeclampsia Immune thrombocytopenia
Gestational thrombocytopenia = 2 - 5 days post delivery Preeclampsia = remits following delivery Immune thrombocytopenia = falls for 5 days after delivery
How to treat thrombocytopenia of lower levels : >50? 20-50? <20?
What is MAHA syndomes causing thrombocytopenia?
Deposition of platelets in small blood vessels e.g. placenta Cardical signs : fragmentation (shistocytes) and destruction of RBC within vasculature Delivery does not change this syndrome
What is seen on blood flm with MAHA syndomes causing thrombocytopenia?
Deposition of platelets in small blood vessels e.g. placenta Cardical signs : fragmentation (shistocytes) and destruction of RBC within vasculature Delivery does not change this syndrome
how many TTP type MAHA syndrome affect symptoms?
TTP (pentad S/S: MAHA, fever, renal impairment, neurological impairment, thrombocytopenia)
What is the leading cause of maternal death in the UK?
VTE
Which leg often has the blood clot in pregnant women?
Left leg
Why may pro-thombotic environment be created in pregnancy?
What is the largest predictor of incidence of PE during pregnany?
High BMI >25
How does VTE cause most maternal deaths?
PE - embolism
Which is the highest risk time for PE?
post partum 6 weeks and 1st trimester
How to manage patients with BMI >25 prophylaxis for PE?
Heparin from 1st trimester
Why is D Dimer not useful for pregnancy?
often elevated in pregnancy - only used for exclusion
Which factors increase risk of thrombosis?
Prevention plan for thromboembolic disease in pregnancy?
Treatment plan for thromboembolic disease in pregnancy?
Why does Warfarin need to be stopped prior to pregnancy?
Is teterogenic so need to wean off Can cause chondrodysplasia punctata - fetal abnormality
Why can LMWH be used in pregnancy but Warfarin cannot be used?
LMWH does not cross the placenta
Warfarin does (is teratogenic) avoid specifically in weeks 6-12
Antiphospholipid syndrome is a thrombophilia associated with pregnancy
When is antiphospholipid syndrome usually diagnosed? *1 history feature + 1 diagnostic test
After 3+ (recurrent) miscarriage + lipid anticoagulant or anticardiolipin antibodies are detected
Other than recurrent miscarriage it also could be: - 1 or more pretern birth before 34 weeks
Antiphospholipid syndrome is a thrombophilia associated with pregnancy
How to treat antiphospholipid syndrome?
After 3+ (recurrent) miscarriage + Lupid anticoagulant or anticardiolipin antibodies are detected
Heparin and aspirin
What are placental causes of PPH?
Placenta praevia
Placenta Accrete
What is PPH defined as?
500ml + loss
5% pregnancies may have more than 1L
Mechanisms of PPH can be determined by the 4Ts?
Tone (uterine atony) = major cause
Tissue
Trauma (major cause)
Thrombin
Other than the 3 Ts and placental abnormalities what else can cause PPH?
Haematological factors: Dilutional coagulopathy after resus DIC in abruption
amniotic fluid embolism
What in pregnancy may predispose to DIC?
Coagulation changes as Tissue factor and Factor 7a can come into contact and start the cascade
in DIC in pregnancy, decompensation (bodys point of failure to maintain haemostasis) is worsened by which conditions?
Amniotic fluid embolism
Pre-eclampsia
also sepsis and placental abruption
What is amniotic fluid embolism?
When tissue factor from amniotic fluid enters maternal blood stream.
causes shivers, vomiting, shock
how to treat amniotic fluid embolism?
use misoprostol to induce labour
Screening for haemoglobinopathies is vital to avoid birth of children with which conditions?
Alpha 0 thalassemia / Hb Barts (in utero death)
Beta 0 thalassemia (transfusion dependent)
HbSS / SCD (sickle clell)
What inheritence pattern do haemoglobinopathies have?
All are recessive (thalassemia A and B and sickle cell)
How does Sickle cell women do in pregnancy?
prophylactic transfusion
Differences between Iron deficiency anaemia and thalassaemia trait?
Iron def: normal or low Hb with low MCH and low RBC
Trait : normal Hv with low Hb and increased RBC
Differences between Iron deficiency anaemia and thalassaemia trait? Hb?
iron def : Hb is normal or low
thalassaemia : Hb is normal
Differences between Iron deficiency anaemia and thalassaemia trait? MCH?
iron def : Low in proportion to Hb
thalassaemia : lower for same Hb
Differences between Iron deficiency anaemia and thalassaemia trait? RBC?
iron def : low or normal
thalassaemia : increased
Which of the following statements is correct?
o In gestational thrombocytopenia, the baby’s platelet count is usually affected
o Thrombocytopenia is rarely found in association with pre-eclampsia
o Thrombotic thrombocytopenic purpura remits spontaneously following delivery
o Platelet count may fall following delivery in babies born to mothers with ITP
Platelet count may fall following delivery in babies born to mothers with ITP
