Tuesday 18 May 2010

Sicke cell anaemia in pregnancy

Genetics
Autosomal recessive disorder
Single point mutation in β-Globin chain in haemoglobin.

Diagram explaining the inheritance 




Types of sickling conditions

(i)Homozygous sickle-cell disease(HbSS)
(ii)Sickle cell/HbC(HbSC)
(iii)Sickle cell /Thalassaemia








Clinical features
Common  features
(i)Anaemia due to chronic haemolysis- This is not so marked in HbSC
(ii)Vaso-occlusive crisis
(iii)Aplastic crisis

Other features
(i)leg ulcers
(ii)gall stones
(iii)acute chest syndrome-pleuritic chest pain,tachypnoea,fever


Sickling crisis  in sickle cell trait patients is precipitated by severe anoxia,dehydration or acidosis.

Diagnosis

Diagnosis is made by haemoglobin electrophoresis.

Effect of pregnancy on disease

(i) sickle cell crisis is more common on pregnancy


Effect of disease on pregnancy
(i)fertility is generally unaffected.
(ii)Genetic transmission of the condition to the fetus
(iii)Perinatal & maternal mortality is increased
(iv) increased risk fetal complications : miscarriage,intrauterine growth restriction,preterm labour
(v) increased risk of maternal complications: thromboembolism,preeclampsia, abruption,infections(probably due to hyposplenism) like UTI,puerperal sepsis
















Management
Prepregnancy
(i)Partner testing
(ii)Folic acid supplementation 5mg/day


Antenatal
(i)Multi disciplinary team involving haematologist,geneticist and obstetrician experienced in managing sickle cell disease.
(ii)Folic acid 5mg/day
(iii) Penicillin prophylaxis to prevent pneumococcal infection as a result of hyposplenism.
(iv)partner screening & genetic counselling -Fetal diagnosis by preimplantation genetics in IVF/CVS/Amniocentesis















(v)Regular checking of haemoglobin and mid stream urine

(vi)regular growth scan

(vii) Management of crisis
      (a)Rehydration
      (b)Pain relief-Morphine.NSAID can cause haemolysis.
      (c)early use of antibiotics if infection is likely
      (d)need to keep the patient warm ; well oxygenated.Pulse oxymetry & arterial blood gas may be necessary.
(viii)Blood transfusion may be necessary ex: to correct anaemia

(ix) Value of exchange transfusion is not well defined.Theoretically this increase the proportion of haemoglobin A and suppress the bone marrow from producing red cells with HbS. This may decrease the incidence of crisis but need to be balanced against the risks associated with transfusion.

(x) It is important to recognize & treat infection early.

(xi) The following treatments used to increase HbF need further evaluation in pregnancy
        (I) hydroxyurea
        (II)butyrate
(xii) Tourniquet should not be used.

Intrapartum care
(i)Avoid : dehydration/hypoxia/sepsis/acidosis
(ii)Epidural analgesia is recommended.
(iii) Sickle cell anaemia is not  an indication for caesarean section
(iv)Give oxygen 4-6 l/min
(v)avoid blood loss as much as possible(Active management of third stage)


Postpartum

(i) Dehydration  & infection should be avoided.

(ii) Risk assessment for thromboprophylaxis should be done.

(ii) Contraception should be discussed-Even though oral contraceptive pills have been implicated in increased risk of thrombo embolism , this is not based on any evidence.


RCOG guideline on management of sickle cell disease in pregnancy

Interventions for treating painful sickle cell crisis during pregnancy (Review)


Powerpoint on Sickle cell disease in pregnancy

Another presentation on sickle cell disease in pregnancy

Powerpoint on sickle cell disease



• Nelson-Piercy C. Handbook of obstetric medicine. Taylor & Francis; 2002.
• Swiet MD. Medical disorders in obstetric practice. Wiley-Blackwell; 2002.

Monday 17 May 2010

Hepatitis C in Pregnancy

Hepatitis C is a RNA virus.
It leads to chronic hepatitis in 70%,cirrhosis in 20-30% in about 10-30  years .
1-6% of cirrohotic patients develop hepatocellular carcinoma.

The commonest risk factor for hepatitis C infection in UK is past or present IV drug abuse.


Serological diagnosis
(I)Testing for Anti-HCV antibodies
(II)HCV RNA using PCR

Hepatitis C anti body indicates previous infection but positive PCR beyond six month indicates chronic infection.
 


Effect of disease in pregnancy
(i)Acute or chronic hepatitis C doesn't seem to adversely affect the pregnancy.
(ii) Vertical transmission is less frequent(3-5% of cases)  than Hepatitis B virus.High viral load,Co-infection with HIV and active i.v. drug use are major risk factors for vertical transmission.
(iii) There is an increased risk of obstetric cholestasis.

Effect of pregnancy on liver disease
(i) pregnancy doesn't induce deterioration in liver disease.

Management.


Preconceptional care

(i) Vaccination against Hepatitis A & B should be offered.

(ii) Current IV drug users should be offered treatment programmes & needle exchange programmes.



Antenatal
(i) Routine screening isn't recommended.
    Selective screening is offered to high risk individuals:
       intravenous drug users
       patients who had multiple blood transfusion in the past
       women with HIV or HBV infection


(ii) Mutli disciplinary management with the involvement of hepatologist.

(iii)Perinatal transmission is uncommon, so there is no specific recommendations on  delivery or breast feeding.

(iv) Patients should avoid alcohol in the interest of minimizing liver damage.

(v) Amniocentesis  does not seem to significantly increase the risk of vertical transmission, but women should be counseled that very few studies have properly addressed this possibility.





Delivery
Universal precautions must be followed.
Caesarean section is not recommended.
There isn't enough evidence to make recommendation on artificial rupture of membranes,fetal scalp electrode and fetal blood sampling but these procedures are better avoided whenever possible.(SOGC guideline)
Pediatrician should be notified about the baby.

Postnatal
(i) anti-HCV antibodies in the baby may be due to tranplacental maternal antibodies.Antibody testing should be delayed up to 18 months post delivery.
(ii)HCV RNA testing could be used.Undetectable levels(less than 100 copies/ml) at 3 months makes vertical transmission unlikely.
(iii) Mother should be referred to hepatologist for antiviral therapy (interferon and ribavirin). These drugs are contraindicated in pregnancy.
(iv) transmission by breast milk is uncommon.
(v)contraception must be discussed.  

A past history  of a child infected perinatally with HCV does not increase the risk of transmission in subsequent pregnancies.   

The Reproductive Care of Women Living With Hepatitis C Infection-SOGC guideline















Sources
• Nelson-Piercy C. Handbook of obstetric medicine. Taylor & Francis; 2002.
• Swiet MD. Medical disorders in obstetric practice. Wiley-Blackwell; 2002.

Hadzić N. Hepatitis C in pregnancy. Arch. Dis. Child. Fetal Neonatal Ed. 2001 May;84(3):F201-204.  

Tuesday 11 May 2010

Uterine inversion in pregnancy

Clinical features

Severe lower abdominal pain in third stage



Haemorrhage


shock out of proportion to bleeding


Uterine fundus not palpable



Mass in the vagina




Management

two important aspects
(A) resuscitation
(B)repositioning of uterus


Help-Call for help(Obstetrician/Anaesthetist/Senior midwives)



Replacement of uterus should go hand in Hand with resuscitation measures


ABC-Airway,Breathing(Remember to give oxygen),Circulation



two wide bore (14/16 G) & Fluid replacement(crystalloid & colliods)


Bloods for FBC,coagulation studies and cross matching (4-6 units)

"Take bloods & label correctly"




The earlier the correction of inversion the more likely the success.


Analgesia should be given


The earlier the reposition of uterus the more likely the success.




Techniques for repositioning uterus

(I)Manual replacement(The Jhonsons Manoeuvre)-Using the fist to push the fundus through the cervix.

(II)Hydrostatic repositioning (O'Sullivan's technique)-
(a) patient is placed in the trendlenberg position
(b)one end of the long tube(2m) with a large nozzle is placed in the posterior fornix
(c) warm saline is infused
(d) leak is prevented by approximating the labia with the hand or a vacuum cup can also be used.

(III)Medical approach
(a)Magnesium sulphate 2-4 g infused over 5 minutes
(b)ritodrine 0.15 mg IV bouls
(c)terbutaline 0.25 mg slow IV bolus
(d) volatile agent as a part of general anaesthesia





(IV) Surgery

(a)Huntingdon's procedure-Allis forceps is used to grasp the dimple of the inverted uterus and then gentle traction is applied.Further application of forceps on the advancing fundus helps in the correction of uterine inversion.

(b)Haultin's technique-posterior aspect of cervical ring is incised to help the Huntingdon's procedure.



Oxytocics should be administered after the correction of uterine inversion.


Non Surgical approach is successful in the majority of the cases.












An excellent presentation on uterine inversion