Influence of maternal factors on the successful outcome of kangaroo mother care in low birth-weight infants: A randomized controlled trial

1 Introduction

Low Birth Weight (LBW) remains a major cause of neonatal morbidity and mortality. Around 16% of newborns experience LBW with an incidence of 18 million annually worldwide. In developing countries, incidence of LBW is two times higher than in developed countries [1]. LBW is associated with many complications such as growth disorders, cognitive disorders, and development of chronic diseases in the elderly [2].

Factors such as maternal age, multigravida, short interpergnancy-intervals, socioeconomic factors, maternal education, and pregnancy weight gain increase the incidence of LBW [3–5]. Another study showed a 1.2 times increased risk of LBW in women with low socioeconomic status and 1.7 times in women with low education [6]. LBW is also closely linked with maternal height [7]. Mumbare et al. [8] showed that maternal weight <55 kg, maternal height <145 cm, and inadequate antenatal care, were the most influential factors that induce LBW [8]. Taha et al. [9] showed that maternal age and parity had significant effects on birth weight [9]. However, Negi et al. [10] on the other hand showed that primigravid had higher risk of having LBW baby and there was no relationship between maternal age, height and weight with LBW [10]. In Indonesia, Trihardani et al. (2011) showed that the risk factors associated with LBW were maternal body mass index, pregnancy weight gain, and parity, while there was no significant relationship found between LBW and maternal age, maternal height, frequency of antenatal care, or interpregnancy-interval [11]. Pregnancy before age 20 or over age 35 has tendency to an unmet need of adequate nutrition for fetal growth [12]. In short interpregnancy-intervals, mother does not have enough time between pregnancies to revover nutrient store, either micro- or macronutrient [13].

Keeping LBW infants warm is a crucial point because of the vulnerability to hypothermia which could led to life-threatening infection, apnea or massive bleeding [14]. Incubator is one way to cope with LBW babies, but it impedes early contact and breast feeding [15]. Some invasive procedures in incubator also induce stress in babies, proved by some studies that showed increasing of heart rate and respiratory rate in infants treated in an incubator [16]. As an alternative, KMC was developed by Martinez and Rey in Bogota (1978), inspired from how marsupials to keep their childern warm [17].

KMC is known to be quite effective in the treatment of LBW, in addition of the ease and inexpensive application. It was very important in many remote areas in Indonesia due to the lack of resuscitation facilities [18]. Majority of studies showed KMC had better effects than conventional method, although these were still controversial [19–21]. Pratiwi et al. [22] showed that the birth weight ≥1500 gr and age >10 days related to the success of KMC. Gestational age ≥34 weeks, KMC duration ≥65 minutes, high maternal education level (p = 0.408) did not influence the incidence of LBW [22].

As many factors contributed to the successful application of KMC, clinicians should have predicted the benefits from the beginning of therapy because neonatal is the most vulnerable period in human life. This study aimed to study the influence of maternal factors on the successful of KMC in LBW.

2 Methods

3 Data analysis

Data were analyzed by SPSS (Statistical Product and Service Solutions, Chicago, IL, USA) 22.0 for Windows. Categorical data were expressed as number and continuous data as mean±SD. Chi-square test (Fisher’s exact test) was used to examine the relation between qualitative variables. T-independent, T-dependent, Pearson correlation were used to evaluate quantitative variables. Significance was determined when p value was <0.05.

4 Results

During the period of June 2015-October 2015, ninety infants were born with LBW. Two mothers were not willing to participate in KMC. Some newborns were excluded from the study, as 45 newborns needed NICU care, 1 had congenital anomalies, 1 had cardiovascular disorders, and 1 newborn died. Finally, about 40 newborns were eligible in this study. No loss to follow up or withdrawal from the study (Fig. 1).

Maternal and fetal demographic characteristics were shown in Table 1. No differences were found between groups in maternal age, parity, gestational age, maternal education, mode of delivery, fetal sex, and Apgar score. The initial measured weight, length, and head circumferences were similar in both groups (p = 0.100; p = 0.353; and p = 0.088, respectively). Last measured weight was significantly higher in KMC group than conventional group (2187.5±371.04 vs 1899±242.55; p = 0.015). The difference of initial and last weight was also higher in KMC group than conventional group (205.5±147.451 vs 96±68.702; p = 0.001). To ensure this weight parameter, we calculated the weight gain velocity. The accurate weight gain velocity was 5.098±2.155 g/day and the estimated weight gain velocity was 5.112±2.168 g/day. As a result, accurate and estimated weight gain velocityand absolute difference percentage were found higher significantly in KMC group than conventional group (p = 0.01; p = 0.009; p < 0.001), but there were no differences of last measured weight Z score found between both groups (p = 0.364). We also found no differences of last measured length and head circumference Z score between both groups (Fig. 2). Although mean difference of initial and last head circumference (cm) showed a significant difference (p = 0.004), other parameters regarding head circumferences show no significant differences. Duration of hospital stay did not differ between conventional and KMC groups (28.4±5.020 vs 23.15±5.184; p = 0.42).

From maternal characteristics, only gestational age was found to influence the differences of initial and last head circumference (–0.314±3.746 vs 1.415±1.064; p = 0.035). However, gestational age was not associated with other parameters. There were no differences among maternal age, parity, maternal education, mode of delivery, fetal sex, and initial Apgar scores with accurate weight gain velocity, estimated weight gain velocity, absolute difference percentage, mean differences of initial and last weight, length, and head circumferences (Table 2).

We plotted a mean weight gain graph. Peak weight regain were shown in day 16, 18, and 29. Although the graph showed irregular weight gains, at last day, weight was increased higher than the initial weight assessment (Fig. 3).

5 Discussion

This is the first study that specifically determined the affect of maternal factors on the success of Kangaroo Mother Care babies compared with conventional therapy in LBW infants. Pratiwi et al. [22] showed no effect of high levels of maternal education (p = 0.408) [22] and Rodriguez et al. [23] showed no difference in weight gain with the application of KMC in LBW born either with spontaneous delivery or cesarean section [23].

KMC is a method of maternal-fetal skin to skin contact as a loving incubator that is applied as soon as possible after birth [24]. This method makes mothers and families as providers of biological and psycho-emotional needs for their children [25]. According to WHO guidelines, continuous KMC is indicated in infants with birth weight below 2000 g. Intermittent KMC can also be useful in infants hospitalized in NICU, but still needs further research [26].

The main point of KMC is emphasized at attachment between parents and childern. Feldman et al. [27] had successfully demonstrated the positive impact in the relationship between mother and child [27]. Athanasopolou et al. [28] showed that KMC resolved negative moods such as anxiety and depression in mothers [28]. KMC procedure also increased the mothers’ confidence and competence in caring for her baby and significantly reduced stress. All of these effects contribute to the improvement to the growth and development [29].

In this study, an assessment of growth was based on infant’s weight, length, and head circumference, which were the important markers of a child health [30, 31]. Bera et al. [32] showed that in infants receiving KMC, the growth parameters and mental development was better than infants who were treated conventionally [32]. Ali et al. [19] showed that infants treated by incubator has higher weight gain per day (19.3 vs.10.4 g, p < 0.001), shorter duration of stay (6.9% vs. 23.2% p = 0.014), lower infection rate (6.9% vs. 23.2% p = 0.014) than babies who applied KMC [19]. Palencia et al. [33] found that the growth in height for age was higher within percentiles weight for age (p = 0.0001). Male gender had a higher weight than females (p = 0.031) [33]. This study was simliar to the study in Indonesia previously. In this study, there we showed that compared to conventional group, last measured weight, difference of initial and last weight, as well as weight gain velocity were higher in KMC group. No differences were found regarding of length and head circumference. Haksari (2004) and Rahmayanti [21] in Indonesia also found no difference between weight/age, length/age, head circumference/age in LBW infant treated with KMC and conventional therapy [21]. In the other hand, Rao et al. (2007) conversely showed that infants treated by incubator has a higher weight gain, head circumference (0:49 vs 0.75 cm, p = 0:02), and body length (0.99 vs. 0.7 cm, p = 0.008) compared with infants who applied KMC [20]. It indicated the need to predict which method gives more benefit, KMC or incubator.

We should highlight some factors several authors argued that weight gain should approximate an intrauterine growth rate of 16.8 to 30.7 g/day [31]. In this study, the accurate weight gain velocity was 5.098±2.155 g/day and the estimated weight gain velocity was 5.112±2.168 g/day, which were still far below the recommended growth rate. The Z score of weight was still below expected average. Newborns were still categorized small for gestational age in the end of the study.

In this study, it was shown that weight and length parameters did not differ by maternal age, parity, maternal education, mode of delivery, fetal sex, and initial apgar score. We only found that in newborns who were born <37 gestational age had delayed growth of head circumference. However, KMC has proved to increase cerebral blood flow, which can act as a nutritional support, mainly to the brain. Korraa et al. [34] found that newborns who received KMC had shown lower cerebral blood flow resistive index (p < 0.05) which indicated improved in cerebral blood flow [34]. The influence of immature organ in preterm babies may be considered and this need further research [35]. This marked that KMC is useful in all condition regardless of maternal and fetal characteristics.

The strength of this study is the follow-up parameters that are better than other studies. The better follow-up rate in the KMC group could be due to the active involvement of the mother in the care of her LBW baby. The limitations of this study is the small samples, only conducted in two institutions, and short follow up period. Further large research is needed to ensure these findings.

6 Conclusion

There were no differences of growth parameters between subgroups of maternal and fetal characteristics except the tendency delayed growth of head circumferences in preterm infants.

Conflict of interest

The author declared no conflict of interest in this study.