Infant mortality can be defined as the number of deaths of children under one year of age per 1000 live births in the same year [1]. It is an essential national health indicator; a high rate of infant mortality may be an indicator of poor healthcare infrastructure or poor health services [1, 2]. A reduction in infant mortality is one of the priorities of global health and international development agendas [3, 4]. It was a priority area during the Millennium Development Goals (MDGs), and it remains as a priority area in the Sustainable Development Goals (SDGs) for 2030 [5, 6]. Over the past two decades, the world has achieved remarkable progress in child survival [4]. Globally, the infant mortality rate has decreased by 50% between 1990 and 2017 [4]. According to a 2017 WHO report, infant mortality accounts for 75% of all under-five deaths [4]. The risk of a child dying before completing the first year of life was six times higher in the African region than that in the European region [4]. Infant deaths in developing countries are mainly due to preventable causes, such as pneumonia and diarrhoea [7]. The majority of infant deaths are due to avoidable causes and can be prevented using basic maternal healthcare service interventions, including the utilization of prenatal care services, skilled delivery, and postnatal care [8–10]. Despite the government’s considerable effort to decrease the number of infant deaths, infant mortality in Ethiopia remains among the highest in the world [11, 12]. One of the key reasons for high infant mortality in Ethiopia is low utilization of modern healthcare services by many women in Ethiopia [13]. Previous cross-sectional studies based on Demographic and Health Surveys (DHS) data in Ethiopia have clearly indicated that utilization of maternal health services is very low in the country [14]. According to the Lancet Global Burden of Disease Study in 2015, to achieve the SDG targets regarding maternal and child mortality by 2030, it will require 91% coverage of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled birth attendance [15].
According to the 2016 Ethiopia Demographic and Health Survey, antenatal care utilization coverage, skilled delivery, and postnatal care utilization was 35%, 62%, 28%, and 17%, respectively [16]. Even though home delivery remains high, primarily in hard-to-reach rural areas, there have been improvements in antenatal care service utilization and institutional delivery in Ethiopia [16]. Furthermore, the Federal Ministry of Health in Ethiopia plans to increase the utilization coverage of antenatal care and skilled delivery to 95% and 90%, respectively, by the end of 2020 [17].
According to the Lancet Global Health, half of the world’s population do not have access to modern health services [18]. However, according to the principles of universal health service coverage, everyone should have access to quality essential healthcare services [19]. The United Nations General Assembly has called on all countries to ensure universal health service coverage by 2030 [20]. Ethiopia is one of the countries with a high disease burden of reproductive health problem, maternal health problem, neonatal and child health problem and infectious diseases problem [21]. In addition, the country has low basic health services coverage and low health service utilization [22]. In 2015, the national health service coverage was 34.3%, ranging from 52.2% in the Addis Ababa city administration to 10% in the Afar region [23]. The universal health service coverage for neonatal and child health was 37.5% [23].
In this study, optimum maternal healthcare service utilization is the utilization of WHO recommended antenatal care visits, tetanus injection, skilled delivery, place of delivery, and postnatal check. The WHO recommends that a pregnant woman should receive a minimum of four antenatal care visits [24]. According to the WHO, the essential components of a basic prenatal care program are: identification of pregnancy, management of pregnancy-related complications, treatment of underlying illnesses, disease screening, preventive measures including tetanus toxoid immunization, de-worming, iron and folic acid, treatment of malaria in pregnancy, a birth and emergency preparedness plan, promotion of healthy behaviours at home, helping the pregnant woman and her partner prepare emotionally and physically for birth and care of their baby, and promotion of postnatal family planning/birth spacing [24]. The attendance of a skilled health professional (doctor, nurse, or midwife) during delivery is also crucial to reduce child deaths. The WHO recommends that women who give birth either at home or in a health institution should stay at a health institution following childbirth [25]. The WHO recommends that regardless of the place of birth, women should not be discharged within 24 hours after delivery [25].
Poor utilization of maternal healthcare services has a significant impact on the outcomes of child health [26]. Utilization of recommended antenatal care during pregnancy improves maternal and child health outcomes [27]. Evidence from DHS data from 17 sub-Saharan African countries showed that having prenatal care provided by a skilled practitioner reduced the odds of neonatal mortality by 30% [28]. A finding from a systematic review done in sub-Saharan African countries also revealed that women receiving at least one antenatal care visit during pregnancy decreased neonatal mortality by 39% [29]. Research has indicated that utilization of prenatal healthcare significantly reduces maternal and child mortality [30, 31]. Prenatal care during pregnancy is critical for the foetus and mother’s health [32]. Prenatal care increases the chance of skilled birth attendance, which can improve the likelihood of child survival in the first year of life [32]. A cross-sectional study in West Africa showed that having any prenatal care was associated with lower infant mortality [33]. A nationally representative health survey in Zimbabwe also indicated that poor quality prenatal care contributes to neonatal and infant mortality; a one-unit increase in the quality of prenatal care decreased infant mortality by nearly 31% [34]. Another finding from a systematic review in Ethiopia showed that antenatal care utilization reduces neonatal mortality by 34% [35, 36]. Having optimum antenatal care follow-up for either chronic diseases or acute diseases during pregnancy can prevent further complications occurring for mothers and infants and reduce the prevalence of low birth weight by improving the nutritional status of a mother during pregnancy [37–39]. Tetanus immunization during pregnancy was associated with a reduction of infant mortality; providing women with two doses of tetanus toxoid was estimated to reduce mortality from neonatal tetanus by 94% [40]. The deaths of early infants caused by neonatal tetanus can be decreased by half through a combination of maternal tetanus immunization and clean delivery practice [41].
Previous finding found that there was an association between deaths of children less than one year old and skilled birth and health facilities delivery [42]. A systematic review from developing countries has shown that delivery at health facilities reduces the risk of under one child mortality by 29% [42]. Another facility-based case control study in India indicated that postnatal check-up after institutional delivery was significantly associated with reduced deaths of children in the early years [43]. A systematic review conducted in developing countries found that frequent postnatal visits reduced neonatal deaths; it was also encouraged women to exclusively breastfeed [44].
From the above evidence, infant mortality is significantly associated with the number of antenatal care visits, tetanus injection during pregnancy, place of delivery, and skilled birth attendance in the midst of other variables. Maternal healthcare service utilization during pregnancy and delivery decreases the risk of infant mortality. However, examining the independent relationship between antenatal care and infant mortality, postnatal care and infant mortality, tetanus toxin (TT) and infant mortality might not give adequate evidence for policy formulation. For example, if a pregnant woman has attended the recommended antenatal care, but she was not assisted by a skilled health professional and did not follow up postnatal care, the survival of her child may be at higher risk. The interrelated nature of these maternal healthcare service indicators needs to be addressed in an integrated way to enhance the survival chance of infants. Therefore, five indices of maternal healthcare services were combined by scoring each indicator to produce a combined score. Combining the indices of maternal healthcare service utilization can help to understand the effect of optimum maternal healthcare service utilization on infant mortality in Ethiopia. We expect that the rate of infant mortality will be lower among women who were high users of maternal healthcare services compared with women who did not use maternal healthcare services.