World Health Organization (WHO) estimated that there were 287000 maternal deaths worldwide in 2010. Of all the deaths, 95% occurred in developing countries (
1), revealing major political, economic and social differences between countries and regional differences, especially regarding women’s health. According to WHO, the estimated maternal mortality ratio (MMR) in Iran in 2010 was 21 per 100,000 live births. Sistan and Baluchestan and Khorasan provinces were the regions in Iran with the highest MMRs, while direct obstetric causes account for 49% of maternal deaths and the main causes are hypertensive diseases, followed by hemorrhage and puerperal infections and pulmonary embolism (
2). Maternal death is used as a parameter to assess the quality of health services by identifying the situations of inequality and contributing to the assessment of levels of health and socioeconomic development of a population (
2). Maternal deaths are the tip of the iceberg of maternal disability and for every woman who dies many more will survive, but often have lifelong disabilities (
2,
3). Severe maternal morbidity or near miss is a newly described condition which has been investigated for 20 years. Near misses are defined as pregnant women with severe life-threatening conditions who nearly die during pregnancy, childbirth or the postpartum period; but with good luck or good care, they survive. A near miss case is a woman with at least one near miss event (
4-
7). Severe maternal morbidity or near miss can be a more valuable indicator in analyzing the obstetric care than maternal mortality, as this condition has greater incidence rates and offers a good opportunity for data collection, as the woman herself can be a source of information. Therefore, the study of severe maternal morbidity or near miss is a key to advanced knowledge about risk factors during pregnancy and it can be a valuable tool for monitoring the delivery of obstetrical care (
5,
8). Once maternal morbidity precedes maternal death, the systematic identification and the study of near miss cases help in further understanding of the determinants of maternal mortality. Unlike developed countries, in Iran there is limited experience with the use of near miss reviews as a tool for monitoring the quality of maternity services in developing countries. There are now a number of statistical data systems that measure indicators of unplanned events caused by errors that had potential to injure patients. Most studies have used Mantel (
9) and Waterstone (
10) classifications as they have been published prior to the proposed WHO classification (
11). The criteria for diagnosis of maternal near miss have been standardized. Three approaches based on different indicators have been proposed to identify severe maternal morbidity/near miss: 1) organ dysfunction (
9); 2) presence of conditions or complications (
10,
12) such as preeclampsia, uterine rupture or severe sepsis; and 3) the level of care complexity such as blood transfusion or intensive care unit (ICU) admission (
13,
14). The WHO Working Group on Maternal Mortality and Morbidity has recently developed a uniform set of criteria for case identification based on three established approaches with clinical, laboratory and management markers (
11). This event is most commonly known as “severe maternal morbidity,” “severe acute maternal morbidity” or “near miss”. WHO (
11) argues that “maternal near miss” is the term that better reflects the notion of “nearly dying but surviving” and recommends its use. The present study aimed to describe the epidemiological profile of severe maternal morbidity/near miss and its maternal characteristics and perinatal outcomes in two referral maternity hospitals. This study was conducted to determine the prevalence of near miss cases and the nature of near miss events and mortalities among the obstetric patients to serve as a complementary method for auditing the quality of maternal health care in our institution. Because maternal deaths have become so uncommon, the practice of analyzing severe maternal morbidity evolved as a surrogate to improve obstetrical and perinatal care. Because avoidance of medical errors serves to decrease the risks for maternal mortality or severe maternal morbidity, the concept of near misses or close calls was also introduced.