Recent Advances in Histopathology - 23Sebastian Lucas

MMR: 11.4/1,00,000 (UK), 120 death a year

India : 178 per 1,00,000

Possible cause of death is very wide Evaluation of causation is complex Medical, social and legal consequences are

profound, prolonged and expensive

Death at anytime during pregnancy, delivery and up to 42 days postdelivery

Deaths after 42days from delivery are included only if they result from a problem that arose before that caesura

PPCM

Prolonged survival in intensive care

Direct Pre-eclampsia, AFE, genital tract trauma and

sepsis, PPH

Indirect Sudden cardiac death, DOA, CHD, VTE, AIDS,

SLE, SUDEP, APLA, Tumors

Coincidental Homicide, road collision, drug toxicity, Cancers

Cause of death

Standard protocol

Information and samples

Placenta

Classic form – sudden cardioresp collapse

Clinical triad

Hypotension / cardiac arrest

Pulmonary vasospam

Coagulopathy with severe bleeding

High mortality ; treatment is supportive

Amniotic fluid, amniotic and fetal squamouscells and hair embolise to small vessels of the lungs

H and E AB HMWCK CD31

Renal glomeruli – fibrin thrombi in capillary lumen – DIC

Uterus – mucosal bleed – entry of AF into uterine veins – via CS incision or mucosal split

Pathogenesis – debated

Acute anaphylactic response with cardiopulmshutdown + triggering the clotting cascade and consumptive coagulopathy

? Eg of SIRS – inappropriate release of endogenous inflammatory mediators, an abnormal maternal response to fetal Ag

Used as defence against claims of clinical negligence – Fatal peri or PPH

AFE : inevitably fatal

Pre-eclampsia and eclampsia – 3rd trimester

Increased BP, oedema and proteinuria

Predisp : essential HT, renal disease & obesity

Clonic-tonic seizures in pre-eclampsia

HELLP Syndrome

Etiopathogenesis – poorly understood Generalised vasculopathy

Mode of acute death HT type intracerebral Hm

Encephalopathy caused by vasogenic edema ( severe generalized version of PRES – due to endothelial damage)

Fatal cardiac arrhythmia

HELLP : intra abdominal Hm

Brain

Intracerebral Hm without pre-exisiting berry aneurysm or predisposing factor (60%)

Diffuse cortical petechial Hm – occipital lobes

Swelling and diffuse cerebral oedema

Kidney

Glomerular endotheliosis (unique)

Endothelial cells are swollen ; glomerular capillaries appear bloodless

Glomerulus may also herniate into proximal tubules

Endothelial cells maybe vacuolated with lipid

Silver staining : string of beads appearance

Uterus and placenta Effects of reduced arterial blood supply on villi + foci

of infarction

Decidua – atherosis, fibrinoid necrosis of spiral arterioles

Liver Gross : blotchy focal or confluent Hm necrosis

Histo : periportal fibrin deposition, Hm and hepatocyte necrosis ( unique )

General autopsy findings of hypovolemicshock

Pallor

Pituitary infarction

Hypoxic – ischaemic neuronal necrosis in brain

Uterine atony – commonest cause Placenta praevia Retained placenta Placental abruption – severe coagulopathy Creta syndromes

Accreta (villi attach direct to uterine muscle)

Increta (invade further into myometrium)

Percreta ( through myometrium)

Genital tract trauma – large babies / iatrogenic ENBLOC removal of genital tract

Uterine rupture – big baby/ small pelvis/ prolonged labour/ drugs

Abortion Spont ( <24 weeks) : septic or aseptic : genital tract

sepsis/ uterine Hm/ molar preg Legal termination of preg Criminal : infection/Hm

Several syndromes with diff pathogensis

Severe cases – end results : bacteraemicseptic sock and multiorgan failure with DIC

Placental examination – critical + microbiological culture + HPE

Maternal blood cultures : aseptic – neck veins or heart

CATEGORY TYPICAL INFECTIONAGENT

PATHOLOGY

1. Unsafe abortion Clostridium spp Genital tract necrotising sepsis ; septic shock; MOF

2. Ruptured membranes E coli Infected and inflamed placenta, cord and membranes, genital tract sepsis; MOF

3. Post delivery Group A Streptococcuspyogenes (GAS)

Genital tract sepsis, sometimes necrotisingwith high bact load; MOF

CATEGORY TYPICAL INFECTIONAGENT

PATHOLOGY

4. Community acquired sepsis

GAS, pneumococcus TSS ; MOF

5. Post partum sepsis related to birth process but genital tract not involved

Gram negative and positive organisms

Localised sepsis, leading to MOF

Collapse and die suddenly Critical to examine the entire length of pulm

artery

Pregnancy is a procoagulant state

Prevents severe Hm when placenta detaches from decidua

10X relative risk of VTE (through out preg to week after delivery)

Common category

Aneurysm, dissection and rupture – 3rd trimester

Etiology :multihit Inherent predisposition + progestrone-associated

weakening of the media

Histo : elastic degeneration, mucin deposits and attenuated muscle

Outcome : collapse from shock

Congenital heart lesion with pulmonary HT Inheritable cardiomyopathy – HOCM, ARVCM Acquired cardiac muscle disease – IHD,

endocardial fibroelastosis, myocarditis SADS – sudden unexpected arrhythmic

cardiac syndrome – negative autopsy – long QT syndrome

Obesity and sudden cardiac death Valvular disease

Heart failure during last month of pregnancy and upto 5 months post delivery

Dilated cardiomyopathy

Nonsp histology

Oxidative proapoptotic stress on myocytes, related to prolactin

Pregnancy increases risk of TTP

Abnormalities of vWF physiology – platelet clustering and adhesion to endothelia of the microvasculature – brain, kidney, heart

Postpartum confusion, MAHA and renal failure

Lab : low platelet but normal CF and fibrin

Preg – relative immunodep state [CMI ]

Viral infection ( HS , hepatitis , influenza ) Listeriosis Tb

2009-10 pandemic – type A/H1N1

3rd trimester preg – influenze pneumonitisand A/c lung injury

Acquired secondary bacterial pneumonia

Preg was the pre-eminent risk factor for death with H1N1 infection

Maternal mortality raises by 10 fold

Late presentation at around time of delivery

Death – Tb or opportunistic infections, sepsis or complications of abortion

Obtain as much as clinical information and lab data as possible before starting the autopsy

Take sterile blood culture; later, retain a femoral venous blood sample

Pay close attention to pulm artery , heart and genital tract

‘Negative’ autopsy : retain a piece of spleen in freezer

To establish cause of death – discuss the case openly with obstetricians, physicians, anaesthestists and intensivists