Incidence of maternal near miss in the public health sector of Harare, Zimbabwe: a prospective descriptive study

Maternal morbidity is part of a continuum from maternal good health to maternal mortality. In any setting, women who suffer severe maternal complications share many circumstantial and pathological factors related to their condition [1]. Some women die as a result of these complications, but a proportion of them narrowly escape death either by chance or due to the quality of care they receive [2]. Maternal deaths (MD) can be likened to the ‘tip of an iceberg’ with the base being maternal morbidity, in that more women survive pregnancy complications than the ones who die [3, 4]. The primary indicator of maternal health care and hence quality of obstetric care is Maternal Mortality Ratio (MMR) [5]. By monitoring only maternal deaths at institutions, very few lessons can be learnt to prevent further deaths. This is further compounded by the fact that in maternal death review meetings most of the patient’s records are either missing or incompletely filled [6, 7]. Quality of obstetric care can be assessed using either outcome indicators like maternal mortality ratio, or MNM indicators or using process indicators such as the use of prophylactic antibiotics for the reduction of puerperal sepsis after caesarian section [1, 8].

In 2009, the WHO introduced the concept of ‘maternal near miss’(MNM) for evaluating the quality of care for severe pregnancy complications [1]. A MNM is defined as a case of a woman who nearly died but survived a complication that has occurred during pregnancy, childbirth or within 42 days of termination of pregnancy [1]. Studying MNM is increasingly being recognized as a useful means to improve the quality of obstetric care, particularly in low and middle income countries [2]. It is estimated that for every woman who dies 20 or more survive severe maternal complications as a result of the pregnancy or delivery [9].

The underlying assumptions of WHO MNM concept are that all maternal deaths involve at least one life threatening condition or organ dysfunction and a substantial proportion of women with one or more of these life threatening conditions are those who have severe pregnancy-related complications or receive critical interventions like blood transfusion and ICU admission [1].

The WHO criteria for MNM are based on clinical, laboratory as well as management based proxies for organ or system dysfunction [1]. The WHO recommends that the maternal near miss approach should be considered in national plans for improving maternal health care [10]. Using near miss indicators has several advantages in that it offers a large number of cases that allows a more rapid and precise assessment of quality of care, it has greater acceptability by involved health workers and institutions since death has not occurred, and it offers an opportunity for interviewing the women themselves [11]. Maternal mortality is among the worst performing health indicators in developing countries [7]. The WHO near miss clinical based criteria when used in Tanzania taking into account available resources, had an improved sensitivity (99.5%) and specificity (100%) for detecting maternal deaths [12].

In Zimbabwe maternal mortality remains high, even in urban settings although women in rural areas are at a significantly higher risk of dying from pregnancy complications [13, 14]. The latest maternal mortality ratio in Zimbabwe is 651 per 100,000 live births [15]. The quality of obstetric care is a large driver of poor maternal outcomes. Recently, there has been some studies that sought to address this issue [9, 14, 16‐18]. The maternal mortality ratio patterns established using these retrospective studies are often imprecise and make it difficult to monitor trends or progress regarding the targets of improving maternal care [5]. The burden of severe maternal morbidity is unknown in Zimbabwe including in the public health sector of Harare. We therefore sought to assess the burden of severe maternal morbidity by calculating the MNM ratio and describe factors associated with MNM in the public health sector of Harare city.

The total number of deliveries in the public sector of Harare was 11,871 during the study period. Most of the deliveries occurred at the local clinics [6475(54%)], while 27% (3185) and 19% (2211) were delivered at Harare and Parirenyatwa hospitals respectively. Of these, 123 women developed SMO of which 13 were maternal deaths and 110 were maternal near misses. The median age for severe maternal outcomes was 28 years. Median parity was two. Most of the women were married, educated up to secondary level and 60.8% were homemakers. Most (80%) were Christians (Table 1). The maternal near miss ratio was 9.3 per 1000 deliveries, 95% confidence interval (C I) of 7.6–11.0 per 1000 deliveries, with a mortality index of 10.6%. For every maternal death, there were 8.5 maternal near miss events. The maternal mortality ratio was 110/100000 live births, 95% C I of 50–170 deaths per 100,000 live births (Table 2). Of the women who developed severe maternal outcomes 66.7% (82) were referred from local clinics, while 24% (30), 8% (10) were booked at Harare and Parirenyatwa hospitals respectively. One woman came from home.

The major underlying causes of maternal near miss were obstetric hemorrhage (31.8%), hypertensive disorders (28.2%) and complications of miscarriages (20%) (Table 3). Among maternal deaths hypertensive disorders of pregnancy were the leading cause accounting for four (30.8%) of deaths, followed by medical disorders [3(23.1%)] and obstetric haemorrhage [3(23.1%)]. The major organ dysfunction among cases with severe maternal outcomes was cardiovascular dysfunction (76.9%), Respiratory dysfunction (69.2), haematologic dysfunction (23.1%) and renal dysfunction (15.4%). There were 9 out of 123 cases of severe maternal outcomes admitted into ICU, giving an ICU admission rate of 7.3 cases per 100 cases of SMO and 88.8% of maternal deaths occurred without ICU admission.

The MNM ratio was 9.3 per 1000 deliveries and the leading cause was obstetric hemorrhage. The MNM ratio was within the range of MNM ratios described by WHO of around 7.5 cases per 1000 deliveries [1]. In a systematic review by Tuncalp et al., the MNM ratio varies depending on the criteria used and is higher in low and medium income countries [21]. Our MNM ratio is higher when compared to the MNM ratio from a South African study, which reported 4.3 per 1000 [22], and lower to that from a study in Tanzania, (23.6 per 1000 live births) [20].. This could be explained firstly by the fact that in this study we used a broader definition of MNM which included complications of miscarriages and ectopic pregnancies unlike the criteria in the South African study, secondly because the Tanzanian study was hospital based.

The MMR in this study was 110 per 100,000 live births which is lower than the national level of 651 per 100,000 live births [15] and a notable decrease from 361 per 100,000 live births in 2010 in the same population [23]. This shows a continued downward trend likely due to increased resource allocation. Most (67%) patients who developed SMO had booked at local clinics i.e. were low risk women. This was similar to findings from the South African study that reported that a significant proportion of serious complications occur in women who are otherwise regarded as low risk [22] highlighting increased vigilance during antenatal clinic visits for apparently low risk women. The leading underlying causes of SMO in this study are similar to the top 5 causes of maternal mortality in Zimbabwe quoted in various studies [9, 17, 23]. This confirms that MNM can be a proxy for MM [1]. The overall MI was 10.6%. which is comparable to the one from a South African study (14%) [22]. The MI was lowest for obstetric haemorrhage (5.4) and high for hypertensive disorders (11.4), abortion complications (12.0) and medical disorders. This is likely because of improved management of obstetric haemorrhage as a result of availability of free blood and in service training in obstetric emergencies funded by aid organizations. However, hemorrhage is still a leading cause of MNM and there is need for continued health system strengthening so as not to lose gains made by wide spread in service training in the management of obstetric emergencies. The MI for medical disorders is distorted by a low number of cases as there were only 4 cases and 3 of them died. A multi-disciplinary approach is however needed when managing patients with medical conditions in pregnancy so as to recognize complications early. While in service training in obstetric emergencies cover all areas there is need to improve the management protocols for hypertensive disorders and post abortion complications. Most deaths as a result of miscarriages were occurring within hours of arrival which suggests the unsafe nature of abortions in the communities. Earlier studies have also reported a higher case fatality rate from hypertensive disorders and this was reported to be due to inadequate case management [23, 24].

The ICU admission rate among SMO is low and most deaths occurred without being admitted into ICU. There is greater demand for ICU at our tertiary hospitals from non-obstetric cases as well as referrals from rural provinces. There is need to have an ICU dedicated to the maternity units alone. There is also need to better equip hospital wards to have high dependency units with adequate human and material resources so as to improve patient outcome.

The MNM ratio of 9.3 per thousand deliveries was comparable to other reports in the region. The mortality index was 10.6%, which is high. Obstetric haemorrhage was a leading cause of severe maternal morbidity though with less mortality when compared to hypertensive disorders and abortion complications. Zimbabwe should adopt the maternal near miss ratio as an indicator for evaluating its maternal health services. There is need for a nationwide study on the incidence of MNM to rule out regional variability and to include facilities that offer comprehensive emergency obstetric care in the sample. Well-equipped maternity HDUs and ICUs should be established to reduce the MI from obstetric emergencies.