Maternal death

# Overview
Maternal death, or maternal mortality, also "obstetrical death" is the death of a woman during or shortly after a pregnancy. In 2000, the United Nations estimated global maternal mortality at 529,000, of which less than 1% occurred in the developed world. However, most of these deaths have been medically preventable for decades, because treatments to avoid such deaths have been well known since the 1950s.

# Maternal Mortality definition
According to the WHO, "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 the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes." (1)
Generally there is a distinction between a direct maternal death that is the result of a complication of the pregnancy, delivery, or their management, and an indirect maternal death that is a pregnancy-related death in a patient with a preexisting or newly developed health problem. Other fatalities during but unrelated to a pregnancy are termed accidental, incidental, or nonobstetrical maternal deaths.
Maternal mortality is a sentinel event to assess the quality of a health care system. However, a number of issues need to be recognized. First of all, the WHO definition is one of many; other definitions may also include accidental and incidental causes.  Cases with "incidental causes" include deaths secondary to violence against women that may be related to the pregnancy and be affected by the socioeconomic and cultural environment. Also, it has been reported that about 10% of maternal deaths may occur late, that is after 42 days after a termination or delivery (1), thus, some definitions extend the time period of observation to one year after the end of the gestation. Further, it is well recognized that maternal mortality numbers are often significantly underreported (2).

# Major causes
The major causes of maternal death are bacterial infection, toxemia, obstetrical hemorrhage, ectopic pregnancy, puerperal sepsis, amniotic fluid embolism, and complications of abortions.
As stated by the 2005 WHO report "Make Every mother and Child Count" they are: severe bleeding/hemorrhage (25%), infections (13%), eclampsia (12%), obstructed labour (8%), complications of abortion (13%), other direct causes (8%), and indirect causes (20%).  Indirect causes such as malaria, anaemia, HIV/AIDS and cardiovascular disease, complicate pregnancy or are aggravated by it.
Complications of Hyperemesis Gravidarum also lead to maternal death.

# Maternal Mortality Ratio (MMR)
Maternal Mortality Ratio is the ratio of the number of maternal deaths per 100,000 live births. The MMR is used as a measure of the quality of a health care system. Sierra Leone has the highest maternal death rate at 2,000, and Afghanistan has the second highest maternal death rate at 1900 maternal deaths per 100,000 live births, reported by the UN based on 2000 figures. Lowest rates included Iceland at 0 per 100,000 and Austria at 4 per 100,000. In the United States, the maternal death rate was 17 maternal deaths per 100,000 live births in 2000. "Lifetime risk of maternal death" accounts for number of pregnancies and risk. In sub-Saharan Africa the lifetime risk of maternal death is 1 in 16, for developed nations only 1 in 2,800.
In 2003, the WHO, UNICEF and UNFPA produced a report with statistics gathered from 2000. The world average was 400, the average for developed regions was 20, and for developing regions 440. The worst countries were:
Sierra Leone (2,000), Afghanistan (1,900), Malawi
(1,800), Angola (1,700), Niger (1,600), Tanzania (1,500), Rwanda (1,400), Mali (1,200), Somalia, Zimbabwe, Chad, Central African Republic, Guinea Bissau (1,100 each), Mozambique, Burkina Faso, Burundi, and Mauritania (1,000 each).
The maternal mortality ratio is often referred to as the Maternal Mortality Rate. This is actually a misnomer as it is in fact a ratio, and not a rate at all.

# Associated risk factors
High rates of maternal deaths occur in the same countries that have high rates of infant mortality reflecting generally poor nutrition and medical care.
Low birth weight of the child increases the risk of maternal death from cardiovascular disease. Subtracting one pound of infant birth weight doubles the risk of maternal death. Therefore, the heavier the birth weight of child, the lower the risk of maternal death.

# Maternal death rates in the 20th century
The death rate for women giving birth plummeted in the 20th century.
At the beginning of the century, maternal death rates were around their historical level of nearly 1 in 100 for live births.  The number today in the United States is 13 in 100,000, a decline by a factor of 100.
The decline in maternal deaths has been due largely to improved asepsis, use of caesarean section, fluid management and blood transfusion, and better prenatal care.