Changes in the clotting factors and venous stasis and thromboembolism (especially after cesarean section).

Thromboembolism may cause death in any of the trimesters of pregnancy.

Thrombolism may also occur after delivery (postpartum).High risk factors for postpartum thrombolism include age over 35 , obesity, post cesarean section.

Mutations in Factor V Leiden and heterozygous factor II can also increase the risk of venous thromboembolism in pregnancy.

The incidence of venous thromboembolism is much higher in women who have both Factor V and factor II mutations.

Increased use of prophylaxis (such as compression stockings in high risk women), can reduce the risk of thromboembolism.

Very high risk pregnant patients (such as patients with a family history and/or personal history of thromboembolism) must be on heparin prophylaxis.

Numerous studies have shown that the use unfractionated heparin (or low molecular weight heparin) with low dose aspirin throughout pregnancy improves fetal outcomes.

2)Haemorrhage:

Postpartum haemorrhage accounts for 50% of the cases of haemorrhage related to pregnancy. The remaining 50% is due to antepartum haemorrhage (This includes placenta praevia and abruptio placentae.) 25% are due to placenta praevia and the remaining 25% is due to abruptio placentae.

Placenta praevia

Placenta praevia is particularly dangerous if it is implanted over a uterine scar. Only a consultant or a senior registrar must carry out the cesarean section for placenta praevia.

Abruptio Placenta

Usually associated with severe pain, but may not have  bleeding per vaginum. Coagulopathy could complicate abruptio placenta.

Postpartum haemorrhage

This topic will be covered in numerous posts .All hospitals must have clear guidelines for the management of postpartum haemorrhage.

3) Hypertensive disorders in pregnancy:

Severe hypertensive disease usually presents around 32 weeks of gestation. Some of the complications of hypertensive disorders in pregnancy include intracranial haemorrhage, acute respiratory distress syndrome,pulmonary edema, cerebral edema etc.

4)Amniotic fluid embolism:

When amniotic fluid finds its way to the maternal circulation, there is a sudden severe reaction in the lungs. This can cause sudden collapse and death, usually during labour.

Proof of the diagnosis is by finding fetal squames in the mothers lungs at autopsy.

5)Puerperal Sepsis:

This is common in developing countries. Prophylactic antibiotics may be given in cesarean section. Prophylactic antibiotics are not recommended in normal vaginal delivery.

6)Deaths during early pregnancy:

This refers to deaths occuring before 24 weeks of gestation.

The common causes of death during this period include ectopic pregnancy, spontaneous abortion and termination of pregnancy.

Ectopic pregnancy presents as abdominal pain with a positive pregnancy test.This can progress to shock and death rapidly if not managed immediately.

7 Deaths due to anaesthesia

This is very rare these days, due to use of modern equipments and anaesthetics.

8)Death due to genital tract trauma

Such as uterine rupture and uterine perforation. This can follow instrumental vaginal delivery.

References:

Pages 175 to 181. Chapter 21. Thrombophilia in Pregnancy by Pankaj Desai and Purvi Patel. Medical Disorders in pregnancy-An Update. Edited by Hiralal Konar and Pralhad Kushtagi. Federation of obstetric and gynaecological societies of India.

Pages 20 to 32.Chapter 3. Maternal and Perinatal Mortality.Obstetrics by Ten Teachers.Seventeenth edition. Edited by Stuart Campbell and Christoph Lees.

1)Severe bleeding- 25%

2)Indirect Causes -20% eg anaemia,malaria and heart disease.

3)Infection- 15%

4)Eclampsia-12%

5)Unsafe abortion-13%

6)Obstructed labour-8%

7)Other direct causes-eg embolism, ectopic pregnancy and anaesthesia related.

The causes of maternal mortality are the same in developed and developing countries.However there is variation in the common causes of maternal mortality, in the developed countries the common causes are thrombosis/thromboembolism,hypertensive disease and cardiac disease, while in the developing countries haemorrhage, sepsis and hypertension tops the list.

Causes of maternal mortality in developed countries:

Direct deaths (In descending order of incidence)

Thrombosis and thromboembolism

Hypertensive disease

Amniotic fluid embolism

Early pregnancy deaths due to ectopic pregnancy, spontaneous miscarriage and legal termnation

Sepsis

Haemorrhage

Genital tract trauma

Other direct causes

Indirect deaths (In descending order of incidence)

Cardiac disease

Psychiatric disorder

Other indirect causes

Direct causes account for about 80% of maternal deaths, the remaining 20% are due to indirect causes.

Social factors that influence maternal mortality:

i)Women’s age: The optimal child bearing age is from 20 to 30 years. There is a gradual increase in the risk of maternal mortality <20 years and >30 years.

ii)Parity: Parity means the number of children. The higher the parity, the higher will be the maternal mortality.

iii)Birth interval: There is an increase risk of maternal mortality with short birth intervals.

iv) Poor socioeconomic status.

v) Bad cultural practices and beliefs.

vi) Nutritional status-eg malnutrition

vii) Environmental factors-eg poor environmental sanitation.

vii)Literacy

viii)Lack of maternity services

ix) Shortage of manpower in the health sector

x) Poor communications and transport facilities.

Important measures to reduce maternal mortality:

i)Early registration of pregnancy.

ii)A minimum of three antenatal check-ups.

iii) Correction of anaemia and dietary supplementation.

iv) Prevention of haemorrhage and infection during the puerperium.

v) Prophylaxis against malaria and tetanus.

vi) Delivery in a very clean environment.

vii)Treatment of medical conditions such as diabetes, tuberculosis and hypertension.

viii)Institutional delivery for women with bad obstetric history and high risk factors.

ix) Training of traditional birth attendants and female health care workers.

x) Promotion of family planning.

xi) Prevention of complications such as eclampsia, malpresentations and ruptured uterus.

xii) Searching for the cause of every maternal death.

References:

Maternal mortality ,pages 20 to 27. Chapter 3.Obstetrics by Ten Teachers. 17th Edition. Edited by Stuart Campbell and Christoph Lees.

Pages 387 to 389. Maternal Mortality Rate.Chapter 9.Preventive Medicine in Obstetrics,Paediatrics and Geriatrics.Park’s Textbook of Preventive and Social Medicine by K. Park. 17th Edition.

Important definitions in maternal mortality:

Maternal Mortality rate:

This is the risk of women dying from “puerperal causes”.

= The total no. of female deaths due to complications of pregnancy, childbirth or within 42 days of delivery from “puerperal causes” in an area during a given year/ The total no. of live births in the same area and year

X 1000

The denominator should include all deliveries and abortions.

Ideally the maternal mortality rate should be expressed as a rate per 1000 live births. But lately the multiplying factor of 100000 is used .This is because of the recent decline in the maternal mortality rate in developed countries. This helps avoids fractions.

Definition of  Maternal Death by W.H.O

A maternal death is defined as the death of a woman while pregnant or within 42 days of termination of pregnancy,irrespective of the duration and site of pregnancy,from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.

Direct and indirect obstetric deaths:

The ICD (International classification of diseases) has recommended that maternal deaths should be classified into direct and indirect deaths.

i) Direct obstetric deaths:

These are deaths resulting from obstetric complications of the pregnant state (pregnancy,labour and puerperium), from interventions,omissions, incorrect treatment, or from a chain of events resulting from any of the above.

ii) Indirect obstetric deaths:

These are deaths resulting from previous existing disease or disease that developed during pregnancy and which was not due to direct obstetric causes, but which was aggravated by physiologic effects of pregnancy.

Late maternal death:

A late maternal death is death of a woman from direct or indirect obstetric causes more than 42 days but less than one year after termination of pregnancy.

Fortuitous death:

Deaths from unrelated causes that may happen in pregnancy or puerperium.

The death certificate must include questions regarding current pregnancy and pregnancy within one year preceding death. This will help improve the quality of data on maternal mortality. This recommendation was made by the 43rd World Assembly in 1990.

The incidence of maternal mortality in different countries:

In the whole world there were 536,000 maternal deaths in 2005. That is an average Maternal Mortality Rate (MMR) of 400 per 100,000.

In the developing countries , the average MMR is as high as 960 per 100,000, an exception being Sri Lanka with a MMR of 58 per 100,000.

Comparism of Maternal Mortality in 1990 and 2005 by regions

Maternal mortality rates are highest in Africa. In some parts of rural Africa it may be higher than 1000 per 100,000 live births.

In developed countries the maternal mortality rate is around 9 per 100,000.

Most maternal deaths are preventable (See my article on causes and prevention of maternal mortality).

References:

WHO- Maternal Mortality in 2005

Maternal mortality ,pages 20 to 27. Chapter 3.Obstetrics by Ten Teachers. 17th Edition. Edited by Stuart Campbell and Christoph Lees.

Pages 387 to 389. Maternal Mortality Rate.Chapter 9.Preventive Medicine in Obstetrics,Paediatrics and Geriatrics.Park’s Textbook of Preventive and Social Medicine by K. Park. 17th Edition.