Despite advances in maternal and perinatal health, statistics related to neonatal mortality and morbidity have not shown significant changes and remain a concern. Deaths in the neonatal period account for 60% in developing countries (1), and maternal health is a common factor. It is estimated that two out of three adverse neonatal outcomes are preventable with effective measures in the care of the pregnant woman, during delivery, and the first week of life (2). According to the World Health Organization (WHO), infant mortality is an indicator of the quality of life that reflects the absence of public health interventions, while it is also a crude indicator of poverty and economic status in this population (3).

WHO defines extreme maternal morbidity as a state in which the pregnant woman almost died during gestation, delivery or puerperium, but survived thanks to timely and adequate care. It includes conditions such as severe postpartum hemorrhage, severe preeclampsia, eclampsia, severe systemic sepsis/infection, and uterine rupture, and considers its surveillance as a strategy for the reduction of fatal maternal-perinatal outcomes (4-7). Seventy-five percent of maternal deaths in the Americas are caused by these complications (8). These conditions clearly have an impact on the newborn, in terms of short- and long-term sequelae, as well as on their quality of life (9), loss of skills (10), and the economic cost to health systems (11). Extreme maternal morbidity events in a population and their effects on the health of the mother-child binomial are considered indicators of quality of health services.

In Colombia, maternal mortality had maintained a downward curve over time until 2019 (12). This could be explained by advances in medical interventions (7). According to data from the Directorate of Epidemiology and Demography of the Ministry of Health and Social Protection of Colombia, between 2000 and 2008, an oscillation between 104.9 and 60.7 maternal deaths per 1000 live births was reported, reaching a figure of 15.1 deaths in 2019 (12). However, this could be a false reality, because the number of deaths does not represent the current poor state of maternal health in the country (6,13). Evidence of this is the fact that by 2020 there was an increase of 38.4% compared to the figures for 2019, i.e., a setback of 8 years. With the advent of the pandemic, pneumonia caused by COVID-19 disease contributed an extra 13.5 % of deaths (14). In general, the causes of maternal death in the highest percentage correspond to obstetric hemorrhage and hypertensive disorders associated with pregnancy (15).

Extreme maternal morbidity experienced an opposite behavior, which showed an increase from 2012 to that reported in 2019 (12), which could be related to a combination of factors (16), including advanced maternal age in the first pregnancy, maternal obesity, chronic diseases, increasing rates of cesarean section, increase in notifications of public health events and increase in the number of migrant pregnant women without any type of pregnancy control and any social health coverage. The national extreme maternal morbidity ratio for 2019 was 36.3 cases per 1000 live births, relative to 2018 of 35.3 cases (12), mainly concentrated in extreme ages (16). Age not only has an impact by increasing biopsychosocial risks but also influences the high proportion of perinatal and late neonatal mortality (17).

he highest proportion of perinatal deaths are registered in the fetal period before delivery, in conditions of prematurity and intrauterine growth restriction (18). In the country, the entities with the highest perinatal and late neonatal mortality ratios also share the highest rates of maternal mortality and morbidity (18). This statistical association is likely related to the high proportion of people with unsatisfied basic needs and the high poverty rate (19), with significant barriers to access to health services, especially during prenatal, delivery, and newborn care. The most frequent causes of perinatal mortality are congenital malformations, respiratory disorders typical of prematurity, bacterial sepsis of the newborn, and secondary to obstetric complications, such as asphyxia (20).

The neonatal period is critical and interventions should be oriented in this direction because actions to reduce infant mortality and to address such an important problem are still deficient. This article proposes an approach based on newborns according to their risk at birth, using characteristics related to the mother, the newborn, and sociodemographics, and in this way, we model the problem based on data capable of providing the probability of a newborn being exposed to extreme maternal morbidity events. Thus, the objective was to determine the risk of exposure of children of mothers with extreme maternal morbidity events.

A secondary data analysis study was developed. The risk of exposure to an extreme maternal morbidity event was analyzed for all births occurring in a high-risk obstetric center and referral site of the public sector in the city of Bogotá throughout 2019. The information was collected from routine notification data of extreme maternal morbidity to the National Public Health Surveillance System and the registry of live births. The variables included in the analysis were: maternal data (age, schooling, residence, health system affiliation, and nationality) and birth data (weight, gestational age, and number of prenatal controls). The outcome of interest was the occurrence of extreme maternal morbidity. The clinical information was organized in an Excel database, where the variables were coded by number and analyzed using R Studio software, version 1.2.5.

Statistical analysis. Descriptive statistics were obtained by measures of central tendency and dispersion for numerical variables and frequencies and proportions for qualitative variables. Proportions were compared using the chi-square test (χ²), to determine statistical significance by p < 0.05. To assess the risk of extreme maternal morbidity, first, chi-square tests were performed for each of the maternal, paternal, and birth data variables. All variables with a p < 0.2 were considered for binary regression.

The present investigation contemplated the parameters established in Resolution 008430 of 1993, which establishes the scientific, technical, and administrative norms for health research. This study is considered a minor risk study.

We collected 2197 records of births occurring throughout 2019 (Table 1). 51.0 % (n =1121) of the births were male. Mean weight was 2920 ± 525.2 g, length was 49.6 ± 3.0 cm, gestational age was around 38 ± 2.1 weeks and there were 5.2 ± 2.8 prenatal controls. On average, 64.5 % (n = 1417) of the births occurred by vaginal delivery, and 35.5 % (n = 780) by cesarean section. Of the births, 2.3 % (n = 51) were the result of multiple pregnancy.

Table 1. Table 1. Characteristics of hospital-registered births, 2019

The characteristics of the mothers are shown in Table 2. The mean age of the mothers was 25.6 ± 6.5 years and of the fathers 28.8 ± 7.8 years. Seventy-nine point four percent (n = 1744) were Colombian and 21.6% (n = 453) were Venezuelan migrants. Eighty-seven.7% (n = 1926) of the mothers were from urban areas and 12.3% (n = 271) were from rural areas. Of the mothers, 77.6% (n = 1705) were affiliated with the health system.

Table 2.

*Other: none, pre-school and no data.

The extreme maternal morbidity events found in our population were high and exceeded the national average. In general, there is significant heterogeneity in the results of other studies, with frequencies ranging from 0.04% to 14.9% of all gestations (9,16).

The ratio of extreme maternal morbidity was lower than the district ratio. In Bogota, extreme maternal morbidity cases between 2015 and 2018 were reported in a total of 19,366 events, with an increasing ratio reaching 61.4 events per 1000 live births (21). Concerning 2020, extreme maternal morbidity maintains a rising curve and 64.7 events per 1000 live births were recorded (14).

Extreme maternal morbidity events, defined according to the WHO protocol, are indicators of the quality of health care, with a direct relationship on maternal and perinatal outcomes. Our study showed that perinatal outcomes in patients with extreme maternal morbidity have a significantly higher risk of being associated with preterm delivery, low birth weight, and higher cesarean section rates. Larger newborns are at lower risk of having been exposed to extreme maternal morbidity events, compared to those who had a fetal weight of less than 2500g. The most commonly encountered extreme maternal morbidity was preeclampsia. Severe hypertensive disorders are the major cause of extreme maternal morbidity worldwide and increase the risk of maternal-perinatal complications by more than 3 to 25 times (22), with a high incidence of preterm delivery and low birth weight (23).

Significantly, the greatest extreme morbidity was observed in adolescent women and older women. In agreement with other studies, we found a higher proportion of adverse perinatal outcomes in pregnant women of extreme age, with a higher risk in those older than 40 years; this group has a higher incidence of comorbidities (22,24), and in adolescents, it is due to lower adherence to prenatal check-ups (25). According to the WHO, advanced maternal age contributes to increased rates of extreme maternal morbidity and maternal mortality. Individual factors such as the coexistence of complications of pre-existing diseases in older mothers (24,26) and general factors such as lack of knowledge of the problem on the part of the patient, inadequate prenatal care, delay in the patient's admission to prenatal control, referral to another level of care or timely treatment, and deficient care of the most severe cases favor a higher rate of complications in these groups.

We found that these extreme maternal morbidity events were associated with higher cesarean section rates. De Almeida et al. (27) observed that anesthesia during cesarean section increased the risk of ventilation to the newborn. Cesarean section reaches up to 13 times higher maternal mortality rates compared to vaginal delivery, twice the risk of obstetric bleeding, and a higher risk of severe obstetric complications in subsequent pregnancies (22).

Our results are consistent with the evidence regarding the association of preterm delivery with extreme maternal morbidity events (28). Having no maternal exposure to any morbidity event may be a protective factor concerning preterm delivery. Results in other studies support these findings and show that obstetric hemorrhage and severe hypertensive disorders are significantly associated with preterm delivery (29). In the study by Mengistu et al. (29), women with severe hemorrhage were more likely to have a very low birth weight newborn. In our study, the risk was found to exist when assessing the combined effect of extreme maternal morbidity with low birth weight.

It was not the aim of the study to assess the risk between the groups of Colombian and Venezuelan migrant patients, but important differences were found, especially in relation to fewer or no prenatal checkups. According to Colombia's 2018 National Demographic and Health Survey (30), despite increases in maternal care coverage in recent years, it is estimated that approximately a quarter of pregnant women still do not access care during gestation.

Due to the current social and political situation, it is necessary to evaluate, through other studies, the differences between these two groups and the different risks, to generate new intervention strategies. Public health surveillance is an important mechanism for decision-making regarding actions to prevent neonatal deaths and adverse maternal and perinatal events (31). Simple and cost-effective interventions, such as prenatal care, labor promotion, hand washing, and exclusive breastfeeding, can reduce them (32).

Hypertensive disorders and obstetric hemorrhage are the most frequent maternal morbidity events. In our study, the association between extreme maternal morbidity and perinatal outcomes is evident. Adverse outcomes, such as preterm delivery, low birth weight, and higher cesarean section rates, have a higher incidence in this group of patients. Our results enable us to conclude that all strategies that allow intervention in extreme maternal morbidity events will not only affect maternal health but also decrease the incidence of severe adverse perinatal outcomes, whose effects are important in the long-term health of the newborn.