Obstetric Haematology Flashcards
(48 cards)
During normal pregnancy…
- Less iron required
- There is an increase in haemoglobin concentration
- The platelet count falls
- The neutrophil count falls
The platelet count falls
How does the FBC change in pregnancy?
- Mild anaemia
- –Red cell mass rises (120 -130%)
- –Plasma volume rises (150%) = net dilution
- Macrocytosis–Normal–Folate or B12 deficiency
- Neutrophilia
- Thrombocytopenia
- –increased platelet size
What are the demands of pregnancy?
- Iron requirement
- Folate requirement
Describe iron requirement.
–300mg for fetus
–500mg for maternal increased red cell mass
–RDA 30mg;
– Increase in daily iron absorption:1-2mg to 6mg
Describe folate requirement.
–Growth and cell division
–Approx additional 200mcg/day required
What is the consequence of iron deficiency?
may cause IUGR, prematurity, postpartum haemorrhage
Describe iron homeostasis.
How does the iron cycle differ in pregnancy?
What is the recommendation of iron and folate in pregnancy?
nFolic acid
–Advise reduces risk of neural tube defects
–Supplement before conception and for ≥ 12 weeks gestation
–Dose 400μg / day
Iron
–No routine supplementation in UK
What is the content of elemental iron?
Pregaday 100mg,
Pregnacare 17mg,
Ferrous Sulphate 65mg (in 200mg dose) ,
Continue for 3 months following correction of Hb
Define anaemia in pregnancy-
Definition
–Hb < 110 g/l 1st trimester
–Hb < 105 g/l 2nd and 3rd trimester
–Hb < 100 g/l postpartum
How do we diagnose iron deficiency anaemia?
How does platelet count change in pregnancy?
Falls in pregnancy
Non-pregnant: 225-249 x 109/L
Pregnant: 175-199 x 109/L
How does platelet count change in pregnancy?
Falls in pregnancy
Non-pregnant: 225-249 x 109/L
Pregnant: 175-199 x 109/L
What are the causes of thrombocytopenia in pregnancy?
- Physiological:
- –‘gestational’/incidental thrombocytopenia
- Pre-eclampsia
- Immune thrombocytopenia (ITP)
- Microangiopathic syndromes
- All other causes: bone marrow failure, leukaemia, hypersplenism, DIC etc.
If plt < 150 x 109/L, < 100 x 109/L, < 70 x 109/L - what is the most likely cause?
What is gestational thrombocytopenia? What is the mechanism? What number is sufficient for delivery? Who is affected? How does it resolve?
- Physiological decrease in platelet count ~ 10%
- >50x109/l sufficient for delivery (>70 for epidural)
- Mechanism poorly defined– Dilution + increased consumption
- Baby not affected
- Platelet count rises D2 – 5 post delivery
How many women with pre-eclampsia get thrombocytopenia? Why does it occur= What is associated with? How does it resolve?
- 50% get thrombocytopenia
- Proportionate to severity
- Probably due to increased activation and consumption
- Associated with coagulation activation–(incipient DIC – normal PT, APTT)
- Usually remits following delivery
How common is ITP in pregnancy? How is it managed? What are the effects of it?
- 5% of thrombocytopenia in pregnancy
- TP may precede pregnancy
- Early onset
- Treatment options (for bleeding or delivery)
- IV immunoglobulin–Steroids etc.
- Baby may be affected
- Unpredictable (platelets <20 in 5%)
- Check cord blood and then daily
- May fall for 5 days after delivery
- Bleeding in 25% of severely affected (IVIG if low)
- Usually normal delivery
What happens in microangiopathic syndromes? What are the consequences?
–Deposition of platelets in small blood vessels
–Thrombocytopenia
–Fragmentation and destruction of rbc within vasculature
Organ damage (kidney, CNS, placenta
What are the MAHA syndromes?
Delivery does not alter course of TTP or HUS
What are the MAHA syndromes?
Delivery does not alter course of TTP or HUS
Coagulation changes in pregnancy…
- Increase the likelihood of bleeding
- Result in a hyperfibrinolytic state
- Are mediated by betaHCG
- Result in a leading cause of maternal mortality
Result in a leading cause of maternal mortality
VTE in pregnancy
B
