A sustained commitment to maternal health issues in Nigeria is vital to the attainment of Millennium Development Goal 5 globally. This is because Nigeria, with an estimated current population of over 160 million, is the most populous country in Africa as well as the second largest contributor of maternal deaths globally. This prospective case control study on the determinants and perinatal outcomes of near miss maternal morbidity was conducted in South Western Nigeria. A prospective approach has an advantage over a retrospective study in investigating etiologic relationships as it deals with incident rather than prevalent cases
. The incidence of near misses in this study was 12%. While this figure falls within the range of 1.17 – 23.8%
 reported by Fillipi et al. in three West African countries (Benin, Cote d’Ivoire and Morocco), it is slightly lower than the estimate of 17% in an earlier Nigerian study carried out in Sagamu. Whereas both locations are in south-west Nigeria, which is populated mostly by Yorubas, their socio-demographic mix differed somehow. Sagamu, for example, has a higher proportion of Hausa – whose maternal health seeking behaviour differed significantly from the Yorubas. As national surveys such as the National Demographic and Health Surveys
 and National HIV/AIDS and Reproductive health Survey (NARHS)
 have shown, the maternal and child health seeking behaviour and indices are much better in areas predominantly occupied by Yorubas (South-West-political zone) compared to those predominantly inhabited by Hausas (North-East and North-West geo-political zones). Thus, the population mix in terms of ethnicity and the associated different maternal health-seeking behaviours may account for the differences in the estimates recorded for the two studies. It is important to note that the estimates from both this study and that of Sagamu are not likely to be representative of the true incidence of the near miss for the entire country because there are wide geo-political variations in health indices in Nigeria and the south west has the best maternal health indices compared to other geo-political regions. In addition, fact that both studies are carried out in tertiary facilities also have implications for the representativeness of the figures for the entire countries.
Haemorrhage and hypertensive disorders in pregnancy were the two leading causes of near misses in this study; this is consistent with earlier studies in most part of the world
[10, 20, 27, 31]. These obstetric events are also the leading causes of maternal death in Nigeria
 and most other developing countries. Severe anaemia attributable to severe malaria contributed considerably to the near miss burden in this study. This may be explained by the holoendemicity of malaria in the study area and it also emphasizes the importance malaria prevention in pregnancy through the use of long lasting insecticide treated bed nets, intermittent preventive treatment and prompt case management of malaria in pregnancy.
In this study, chronic hypertension has the strongest association as a risk factor for near misses with a seven fold increase in risk. Hypertension and diabetes have been predictors of near misses in the United Kingdom
. Chronic hypertension considerably increases the risk of complications in pregnancy like superimposed pre-eclampsia, placental abruption, intra-uterine growth retardation and preterm delivery among others
. Therefore, chronic hypertension in pregnancy may be a risk marker and a premise for referral to a higher facility. Pregnant women with chronic hypertension (or any other medical condition) need to be carefully monitored and managed during pregnancy in order to prevent various potential complications. In addition such women must be managed in a facility that can provide emergency essential obstetric and neonatal care. The increase in the occurrence of chronic diseases in developing countries
[34, 35] and its relationship with pregnancy outcomes require further research.
Phase one delay, which is the delay in making the decision to seek care, was also an important risk factor for near miss in this study. Delays in accessing obstetric care during life-threatening complications is a major reason for poor maternal health outcomes in developing countries
. In our study about three-fifths (60.0%) of the near miss cases experienced either phase one and phase two delays (delay in reaching health facility) which resulted from underestimating the severity of various pregnancy-related conditions, lack of available transport particularly for problems occurring in the night as well as first seeking care from a facility that is ill-equipped to provide emergency obstetric care. Poor knowledge of risk associated with various pregnancy warning signs as well as the failure to identify health facilities well equipped for the provision of emergency obstetric services may play a major part in care-seeking decisions. Our findings that antenatal care attendance and knowledge of complications have significant protective effect against near-miss are relevant in this regard. These findings have significant implications for interventions alongside the various phases of delay are modifiable through appropriate interventions. Antenatal care offers a unique platform for the provision of cost effective health interventions which will ensure healthy outcomes for pregnant women
. These include health promotion and preventive services; early detection and treatment of complications and existing diseases; birth preparedness and complication readiness together with promoting male participation. All these are the essential ingredients of quality antenatal care.
The determinants most amenable to change are those linked to obstetric interventions for instance, emergency caesarean section (odds ratio 3.72) and assisted vaginal delivery (odd ratio 2.55). Waterstone et al. also found a strong association between emergency caesarean section and near misses in the United Kingdom. The increased odds of near miss may be associated with the outcome or survival of a near miss rather than being a risk factor due to the temporal sequence of the events. This is because such treatment modalities are employed after the occurrence of a complication and not vice-versa. This notwithstanding, this increased risk associated with emergency caesarean section may be related to the aversion of women and their family members towards caesarian delivery in developing countries such that even in event of a complication women are reluctant to access care until their conditions become life threatening.
When socio-demographic factors alone were considered as a group, being unmarried was the only significant determinant among the socio-demographic characteristics (odd ratio 3.09). It however, became insignificant after adjustment for the proximate risk factors. Marital status, although not amenable to change, may bring to light the issue of male involvement in obstetric care. Adewuyi et al. in an interventional study in south western Nigeria demonstrated that women who lacked male support were more likely to require emergency obstetric care
Perinatal outcomes are important indicators of maternal and newborn health care. In this study, stillbirth (odds ratio 7.15) low birth weight (odds ratio 3.38), and post mature pregnancy (odds ratio 3.24), were strongly associated with near misses. Although several studies have reported the link between maternal morbidity and adverse perinatal outcome very few have described their relationship to near miss maternal morbidity. An example of the latter was the study of Fillipi and her colleagues in Burkina Faso where they also demonstrated a significant association between near misses and stillbirth
. Considerably, the factors that increase the risk of adverse maternal and perinatal outcomes are quite similar for instance inadequate care during pregnancy, inappropriate management of complications, lack of newborn care and so on. Therefore, efforts directed at ensuring maternal health will have a multiplier effect which will invariably impact on the reduction of child mortality. This becomes highly significant in the light of the attainment of the Millennium Development Goals particularly MDG4 AND 5.
A challenge in a study of this nature is the number of ‘cases’ as near miss is a rare event. However, this was addressed by using a high case to control ratio (1:4) thus increasing the statistical power of the study. In addition, attempts were made to minimize some of the problems associated with a case control design. For instance, recall and misclassification biases were lessened by using incident rather than prevalent cases as well as employing validated operational definitions in the selection of cases. Lastly, although the study was conducted over a one year period there were times the study was discontinued due to circumstances beyond the control of the researchers particularly industrial action by health workers; which interrupted the study for a period of time. Hence the near miss rate in this study was limited to an uninterrupted six-month period. Studies on determinants and perinatal outcomes of near miss that address these limitations need to be performed in future, preferably prospective multicenter study carried out over a period of two years or more to generate more stable estimates. Also, near-miss studies need to be conducted in other parts of the country to produce a more comprehensive national picture of the near miss morbidity for Nigeria. Finally, it is imperative that findings from this study be used to inform interventions as Nigeria continues to strive towards achieving the fourth and fifth Millennium Development Goal.