Table 3. Difficulties reported and modifications applied to the World Health Organization maternal near-miss tool in middle-income countries.

Author	Setting	Modifications applied in study	Comments and problems reported by study researchers
Lower-middle-income countries
Kaur et al., 201443	India, Himachal Pradesh	Addition of items to clinical criteria (severe pre-eclampsia; eclampsia)a Addition of item to laboratory criteria (sepsis)b Addition of item to management criteria (intensive care unit admission)	NA
Kushwah et al., 201448	India, Madhya Pradesh	NA	Maximum units of blood available in study institute were 3 units as blood bank was not well supplied. Researchers believed that WHO’s criterion of receiving 5 or more units of blood was less applicable in a resource-poor institute.
Luexay et al., 201461	Lao People's Democratic Republic	Simplified modification of WHO tool for use in the communityc	Researchers concluded that maternal near misses could have been underestimated by application of the WHO definition of maternal near miss, which relies on good laboratory and management-based criteria. Adaptation of near-miss criteria for low-resource settings may benefit lower-middle-income countries where health services are also poorly resourced.
Pandey et al., 201442	India	Omission of markers from laboratory criteria (pH; PaO2/FiO2) Lowering threshold for use of blood products to 2 units of blood	NA
Sangeeta et al., 201527	India	NA	Researchers concluded that in low-resource settings, interventions need to be developed with the local context in mind.
Kulkarni et al., 201650	India, Maharashtra	Addition of item to clinical criteria (anaemia)d	NA
Parmar et al., 201635	Papua New Guinea	Omission of markers from laboratory criteria (pH; lactate; glucose and keto-acids in urine; PaO2/FiO2) Lowering threshold for use of blood products to 3 units of blood Addition of criteria (continuous use of vasoactive drugs; intensive care unit admission)	Data collection in accordance with WHO maternal near-miss guidelines, adjusted for local factors, is possible in a busy maternity unit in a resource-poor setting. Researchers concluded that such data have the potential to improve early detection of life-threatening conditions and hence obstetric outcomes.
Parmar et al., 201635	India	NA	Researchers noted that the WHO classification was remarkable for identifying the most serious cases with higher risk of death. However, the WHO classification showed a high threshold for detection of maternal near miss. Researchers therefore concluded that the method was missing a significant proportion of women with conditions such as pre-eclampsia and eclampsia.
Bolnga et al., 201768	Papua New Guinea	NA	Papua New Guinea’s resource-poor setting lacks the capacity to perform some of the WHO-recommended laboratory investigations such as pH and lactate. Researchers noted that use of locally relevant criteria was also important to avoid underestimation of the true burden of maternal near miss as previously reported in other resource-poor settings.
Panda et al., 201832	India, Odisha	Addition of items to clinical criteria (haemorrhage; hypertensive disorders; abortion; sepsis) Addition of items to management criteria (intensive care unit admission) Addition of definitions of critical interventions (emergency postpartum hysterectomy; immediate blood transfusion)	NA
El Agwany, 201946	Egypt	NA	Researchers could not apply the criteria due to lack of resources.
Gabbur et al., 201959	India, Karnataka	NA	Researchers concluded that modification of the WHO tool is required as currently it leads to underestimation of maternal near miss.
Herklots et al., 201969	United Republic of Tanzania, Zanzibar	Not modified (researchers reported the tool was applicable in this setting)	Conclusions about maternal near miss are dependent on the quality of data and challenges to this should be acknowledged. Researchers recommended adhering to the WHO criteria (adjusted to specific settings as needed) to enable meaningful comparison between similar reference populations.
Jayaratnam et al., 201971	Timor-Leste	Not modified	Determining a clear diagnosis in a woman with maternal near miss is difficult due to presence of multiple symptoms, lack of diagnostics due to fast deterioration of the woman and lack of laboratory-based markers. Researchers concluded that maternal near-miss criteria must be modified to the local context to enhance incorporation of cases (e.g. requiring lower transfusion requirements) in future studies.
Oppong et al., 201947	Ghana	Addition to definition of coagulation in organ dysfunction criteria (bedside clotting time of > 7 mins)	Organ system-based criteria are regarded as the most specific means of identifying maternal near miss. However, researchers argued that these criteria require ready availability of laboratory tests and medical technologies, thus impeding their use in many low-resource local settings.
Owolabi et al., 202022	Kenya	Adjustments were: lowering threshold for use of blood products to 2 units of blood (Kenyan method) Addition of items (laparotomy; definition of shock; treatment with oxygen face mask)	Kenyan method yielded 1.4 times the numbers of maternal near miss than the WHO method. Researchers concluded that there is under-reporting using the WHO maternal near-miss method.
Upper middle-income countries
Morse et al., 201123	Brazil, Rio de Janeiro	NA	As bed availability and intensive care unit admission criteria are not the same, researchers noted that use of intensive care unit admission as a marker is questionable because it is affected by level of complexity of care in a health setting and organization of obstetric care.
Lotufo et al., 201225	Brazil, São Paulo State	NA	Researchers reported no difficulties in using and identifying the WHO criteria, with the exception of certain clinical criteria (e.g. gasping, cyanosis and bedside clotting tests) which generally occurred before starting complex care in the intensive care unit.
Shen et al., 201326	China	NA	The study applied 16 of the 25 WHO criteria. Researchers noted that some women in their study received blood transfusion of < 5 units or intubation related to anaesthesia and therefore did not meet the WHO criteria. Women with pre-eclampsia without jaundice and loss of consciousness for < 12 hours were not included in the WHO clinical criteria group. In the laboratory-based group, women with maternal near miss were differentiated by oxygen saturation, blood creatinine level, platelet count and total bilirubin. Researchers reported it was impossible to always obtain blood pH or lactate level, because these parameters were not routinely checked in their institute.
Naderi et al., 201580	Islamic Republic of Iran	Beside the collection of data on life-threatening disease, researchers added a form based on a published method.5 Four groups were added to the form (haemorrhagic; hypertensive; management; and systemic disorders)	NA
Oliveira & Da Costa, 201576	Brazil, Pernambuco	NA	Mechanical ventilation was required in less than one quarter of cases of maternal near miss. Researchers noted that this finding may be attributed to local differences in accessibility of resources and interventions. It is one of the drawbacks of criteria based only on treatment because a more complex hospital and laboratory structure is required.
Soma-Pillay et al., 201537	South Africa	NA	The WHO tool identified five potentially life-threatening conditions: severe postpartum haemorrhage; severe pre-eclampsia; eclampsia; sepsis or severe infection; and ruptured uterus. Researchers noted that conditions such as abruptio placentae, non-obstetric infections and medical and surgical disorders were also important causes of maternal morbidity. Researchers recommended that the WHO tool should expand the categories of potentially life-threatening conditions.
Ghazivakili et al., 201681	Islamic Republic of Iran	NA	Researchers noted that a limitation of the WHO tool is that application of criteria based on organ failure requires relatively sophisticated laboratory and clinical monitoring. Underestimating occurrence of maternal near miss due to lack of equipment or unavailability of some tests is therefore possible.
Mohammadi et al., 201639	Islamic Republic of Iran	Lowering threshold for use of blood products to 4 units of blood Increasing threshold for platelets to < 75 000 per mL Addition of items to laboratory criteria (rapid reduction of > 4 g/dL in haemoglobin concentration)	NA
Norhayati et al., 201629	Malaysia	NA	Researchers noted that use of the WHO criteria was limited in smaller health facilities. Laboratory-based markers (e.g. pH, PaO2, lactate) and management-based markers (e.g. vasoactive drugs and hysterectomy) were less likely to be applicable in these health facilities.
Akrawi et al., 201741	Iraq	Lowering threshold for use of blood products to 3 units of blood Addition of item to management criteria (admission to close observation care unit >  6 hours) Addition of items to clinical criteria (prolonged labour;e anaemia)f	NA
Iwuh et al., 201844	South Africa	Addition of items to definition of severe maternal complications (acute collapse or thromboembolism; non-pregnancy-related infections; medical or surgical disorders)	NA
Oliveira Neto et al., 201877	Brazil, São Paulo State	NA	Researchers noted that arterial blood gas sampling was not routinely collected in all pregnant or postpartum patients admitted to the intensive care unit. PaO2 records were missing in some cases of maternal near miss. When evaluation of the level of consciousness by the Glasgow coma scale was compromised (due to residual effects of anaesthetics in the postoperative period, or by the use of continuous sedation), the Glasgow coma score of 15 was used as a criterion. Management criteria and not laboratory criteria would be useful to identify severe maternal outcome because they are more related to organ failure. Researchers noted that arterial blood gas sampling was not routinely collected in all pregnant or postpartum patients admitted to the intensive care unit. PaO2 records were missing in some cases of maternal near miss. When evaluation of the level of consciousness by the Glasgow coma scale was compromised (due to residual effects of anaesthetics in the postoperative period, or by the use of continuous sedation), the Glasgow coma score of 15 was used as a criterion. For the variable use of vasoactive drugs, researchers noted that WHO does not establish any other criteria for stratification of severity (e.g. blood pressure levels or whether vasodilator or vasoconstrictor drug used) which could be useful for this purpose. Researchers argue that these issues should be better addressed and possibly changed.
De Lima et al., 201934	Brazil, Alagoas	Researchers noted that intensive care unit admission was not included in the WHO criteria but was an important marker of maternal severity in their study (identified in 94.5% of pregnant women)	Researchers noted that, in contrast to laboratory and management criteria, clinical criteria are important for low-income regions, because no complex laboratory and hospital infrastructures are required. Limitations of laboratory and management criteria are that most of these criteria require high-complexity units, wards, equipment or facilities for their use. Women experiencing near miss may therefore be missed. Lowering the numbers of packed red blood cell units or including disease-based criteria was necessary in low-resource settings to classify women as near miss.
Mu et al., 201979	China	NA	Lack of high-quality medical institutions in rural areas is a problem for maternal health. In recent years, China has strengthened management of women with severe complications so that they must give birth in tertiary hospitals. The researchers argued that the lack of tertiary hospitals in rural areas will affect accessibility of pregnant women to high-quality health care.
Heemelaar et al., 202038	Namibia	Adapted tool for middle-income countries Lowering threshold for use of blood products to 4 units of blood Addition of criteria (laparotomy other than caesarean section or ectopic; pregnancy < 12 weeks) Addition of items to clinical criteria (eclampsia; uterine rupture; non-obstetric sepsis)	The researchers noted the limited availability of laboratory tests and management options resulting in under-reporting of maternal near miss.
Verschueren et al., 202045	Suriname	Evaluation of the WHO maternal near-miss tool by comparing the Suriname obstetric surveillance system with WHO maternal near miss, Namibian and sub-Saharan African tools, to identify the most useful method	The researchers concluded that the WHO tool leads to underestimation of the prevalence of severe complications as the tool does not include certain disease-based conditions.
Multiple countries
De Mucio et al., 201630	Colombia, Dominican Republic, Ecuador, Honduras, Nicaragua, Paraguay, Peru	Omission of items from laboratory criteria (glucose and keto-acids in urine) Lowering the threshold for use of blood products to 3 units of blood	NA

NA: not applicable; PaO₂: oxygen arterial pressure; PaO₂/FiO₂: ratio of arterial oxygen partial pressure to fractional inspired oxygen; WHO: World Health Organization.

^a Severe pre-eclampsia (blood pressure of 170/110 mmHg measured twice); proteinuria of 5 g or more in 24 hours; and HELLP syndrome (haemolysis, elevated liver enzymes and low platelets) or pulmonary oedema or jaundice or eclampsia (generalized fits without previous history of epilepsy) or uncontrollable fits due to any other reason.

^b Sepsis or severe systemic infection, fever (> 38 °C), confirmed or suspected infection (e.g. chorioamnionitis, septic abortion, endometritis, pneumonia), and at least one of the following: heart rate > 90 beats per minute, respiration rate > 20 breaths per minute, leukopenia (white blood cells < 4000/μL), leukocytosis (white blood cells > 12 000/μL).

^c See the supplementary files of the original article for the complete list.⁶¹

^d Anaemia was defined by the researchers as haemoglobin level of < 60 g/L or clinical signs of severe anaemia without acute haemorrhage.

^e Abnormal or difficult childbirth or labour for more than 24 hours.

^f Low haemoglobin level (< 6 g/dL) or clinical signs of severe anaemia in women without severe haemorrhage.

Note: See Box 1 for the WHO inclusion criteria.