Original Article

Incidence of Hypoglycaemia and its Determinants in Neonates Admitted in Neonatal Intensive Care Unit

Introduction

Hypoglycaemia is one of the metabolic problems occurs in the neonatal period.¹Glucose is the sole energy source for brain development during neonatal period.²Neonates have high energy requirements and insufficiency of the enzyme and substrates involved in energy production in this period can lead to hypoglycaemia.³The incidence of hypoglycaemia in newborns is estimated to be 1-3 per 1000 live births.⁴The foetus depends on maternal metabolism and placental circulation to provide glucose, free fatty acids and amino acids which are necessary to meet its energy requirements and during birth abrupt cessation of glucose supply from the placenta leads to hypoglycemia.⁵Undiagnosed hypoglycaemia can have long term neurological consequences.⁶Usually the transition from intra-uterine glucose regulation to extra-uterine adaptation develops in first 24 hours of age.⁷The most common metabolic abnormality in newborns is hypoglycaemia and this results in increased morbidity and mortality.⁸Severe glucose deficiency can potentially leads to cerebral energy failure and impaired cardiac performance.⁹Hypoglycaemia which lasts for prolonged period or recurrent hypoglycaemic episodes may result in poor neurological development in neonates.¹⁰Untreated hypoglycaemia may leads to mental retardation of varied severity.¹¹The prognosis of new born who had hypoglycaemia depends on how promptly and efficiently it is managed.^12,13

In-spite of advancing health care system the admission of neonates to the neonatal unit with hypoglycaemia had been increasing. Thus identifying the risk factors of neonatal hypoglycaemia is very essential to formulate the prevention policy in neonatal unit. Even though some risk factors were documented in literature, these factors are centre specific. Hence we can expect the difference in strength of association between the risk factors and the incidence of hypoglycaemia.

Only few studies have been conducted to identify the incidence of hypoglycaemia among neonates. A study conducted among 50 neonates in a neonatal unit and reported that 30% had hypoglycaemia.¹⁴ De et al reported that among 150 neonates 32% had hypoglycemia.¹⁵Practice Essentials Neonatal hypoglycaemia is defined as a plasma glucose level of less than 30 mg/dL (1.65 mmol/L) in the first 24 hours of life and less than 45 mg/dL (2.5 mmol/L) thereafter is the most common metabolic problem in newborns. Major long-term sequelae include neurologic damage resulting in mental retardation, recurrent seizure activity, and developmental delay and personality disorders. Some evidence suggests that severe hypoglycaemia may impair cardiovascular function. Hypoglycaemia had significant association with neonatal risk factors like prematurity and birth weight.¹⁶

In this study in addition to incident of hypoglycaemia, the symptoms exhibited in neonates during hypoglycaemia (jitteriness, lethargy, convulsion, apnoeic spell) were also identified. Moreover association of hypoglycaemia with neonates with birth asphyxia, sepsis, and hypoglycaemia were also elicited. Added to this the association of hypoglycaemia with type of feed for the neonates and the duration of neonatal unit stay were also identified. For health care professionals the knowledge of neonatal hypoglycaemia and knowing the risk factors and the signs and symptoms will help them to act at once and thus prevent the complications and add an impact on the quality of care to the neonates. Since nurses are primarily taking care of the neonates in neonatal intensive care unit (NICU) round the clock and also involved in planning nursing care for neonates their role includes prevention, detection and treatments of neonatal hypoglycaemia and neonatal hypoglycaemia screening. Knowledge on incidence of neonatal hypoglycaemia and the risk factors will aid them in formulating prevention strategies in neonatal unit. Hence this study is aim to assess the incidence and risk factors of hypoglycaemia.

Materials and Methods

A prospective observational design was adopted for the study to identify the incidence of hypoglycaemia and its determinants among neonates. The study was conducted in NICU of a tertiary care hospital during December 2021 to January 2022.The bed strength of NICU is 60. It has 3 different levels. Level 1 has 31 beds; level 2 has 15 beds and level 3 has 14 beds. In level 1 and 2 mothers are allowed to stay with neonates and in level 3 during visiting time the mothers can see their neonates. Since case method of nursing assignment method is followed in NICU, this aids them in close monitoring of assigned neonates and to detect hypoglycaemic clinical signs and symptoms. Based on prevalence of hypoglycaemia among neonates in NICU as 12% (Jawaharlal institute of postgraduate medical education and research, NICU data) at 5% absolute precision and 90% confidence level 115 neonates were enrolled in the study. The samples were calculated using the software open epi version 3. Neonates admitted in NICU and whose parents gave willingness to allow their neonates to participate in the study were included in the study. Neonates who expired within first 2 hours of life were excluded from the study. Every day neonates who met the inclusion criteria were selected through convenient sampling method. Informed consent was obtained from parents after explaining the purpose of the study, benefits to the participants, the risks involved, maintenance of confidentiality of the data collected and freedom to withdraw from the study.

Demographic and clinical characteristics of neonates and mothers were collected by interview with mother and from medical record. Neonates were observed daily and hypoglycaemic data was collected. It took 45 minutes for each neonate.

Data collection instrument had three sections. The first section includes clinical and demographic characteristics of the neonates. It comprised of gender, gestational age, birth weight, age, term or preterm, intra uterine growth retardation, small or large for gestation, very low birth weight or extremely low birth weight, history of asphyxia, poor feeding, sepsis, anuria, encephalopathy, respiratory distress syndrome, jaundice, hypothermia, polycythemia, RH incompatibility vomiting, resuscitation at birth and also nutritional data like duration of intravenous fluid, duration of oral feed. It also included respiratory support like duration of mechanical ventilation. It also had duration of NICU stay.

Second section had on maternal clinical characteristics. It comprised of mode of delivery and history of diabetes mellitus, pregnancy induced hypertension, twins and gestational diabetes mellitus. Third section dealt with hypoglycaemia like age (in hours) at which first episode detected, blood glucose value at that time, whether accompanied by symptoms like jitteriness, lethargy or apnoeic spell, whether the neonate had single or multiple episodes of hypoglycaemia.

The content validity of the three sections of the tool was obtained from the experts of neonatology and nursing field. Reliability was examined by Cronbach’s alpha (alpha-0.6) for the three sections of the tool.

Data were analysed using statistical package for social sciences (SPSS) version 25. Both descriptive and inferential statistics were used for analysis of data. Descriptive statistics (frequency, percentage) were used to describe the clinical and demographic variables of study participants. Chi-square test was used to identify the association of hypoglycaemia with clinical variables. Logistic regression analysis was used to explore the determinants of hypoglycaemia.

Results

Most of the neonates were male and 36.5% were preterm. 34.8% had low birth weight and mean gestational age was 37.52. About 13.9% had respiratory distress syndrome and 92.2% had less than 5 days of NICU stay. Most of the neonates were born by caesarean section. Twenty-seven percentage and 13% of mother had pregnancy induced hypertension and gestational diabetes mellitus respectively. About 12.2% had twin pregnancy (Table 1).

Table 1illustrated that majority of the neonates were male and 36.5% were preterm. Their mean gestational age and birth weight were 37.52 and 2311kg respectively. About 14% had respiratory distress syndrome and jaundice. 92.2% had less than 5 days of NICU stay.

Majority of the neonates were delivered by caesarean section.27.8% of mother had pregnancy induced hypertension and 13% had gestational diabetes.

Among 115 neonates 30.4% had hypoglycemia. About 68.5% had single episode of hypoglycemia. Symptoms like jitteriness and lethargy were exhibited in 11.4% and 8.5% respectively (Table 2). There was significant association between hypoglycemia and neonatal categorical clinical characteristics like small for gestation, intra uterine growth retardation, birth asphyxia and history of poor feeding (Table 3).

Table 2illustrated that 68.5% neonates had single episode of hypoglycaemia and mean lowest blood glucose value recorded was 11.31 mg/dL.

Table 3Illustrated that there was significant association between hypoglycaemia and neonatal and maternal categorical clinical characteristics like small for gestation, intra uterine growth retardation, birth asphyxia, history of poor feeding and gestational diabetes mellitus.

There was significant association between hypoglycemia and neonatal continuous clinical characteristics like birth weight and length of stay in NICU (Table 4).

Table 4illustrated that there were significant association between hypoglycaemia and neonatal continuous clinical characteristics like birth weight and length of stay in NICU.

Hypothermia, sepsis, prematurity, small for gestation, intra uterine growth retardation, birth asphyxia. Twin pregnancy were identified as significant determinants of hypoglycemia among neonates (Table 5).

Table 5 illustrated that there was significant association between hypoglycaemia and risk factors such as hypothermia, sepsis, prematurity, and small for gestation, intra uterine growth retardation, and birth asphyxia, twin pregnancy, convulsions and lethargy.

Discussion

This prospective observational study included 115 neonates. The incidence of hypoglycaemia was 30.4%. Similarly a prospective longitudinal study conducted by De et al in India among 150 neonates over a period of six months revealed that 32% had hypoglycaemia.¹⁵Inconsistent with this an observational study conducted by Thinesh Kumar et al in institute of obstetrics and gynaecology, among 1883 neonates showed that 33.3% had hypoglycaemia.¹⁷ A prospective longitudinal study conducted from October 2017 to October 2018 among 50 neonates reported 30% of hypoglycaemia.¹⁴Furthermore a longitudinal study among 100 neonates showed the incidence of hypoglycaemia as 15%.¹⁸In addition to this a study conducted in Tehran from June 2004 to march 2005 identified the incidence of hypoglycaemia as 15.15%.¹⁹Similarly a study carried out by Ali et al from May 2019 to December 2019 among 398 neonates showed 10.55% hypoglycaemia.²⁰In consistent with this a longitudinal study conducted in Bangalore among 100 neonates revealed that the incidence of hypoglycaemia was 10%.¹⁰In addition to this a prospective case-control study done in Bangladesh among 186 neonates revealed that the incidence of hypoglycaemia was 17.2 %.¹⁶ In contrast to this a study has reported the incidence was only 8.26%.²¹

Among 30.4% of hypoglycaemia 68.5% had single episode and 31.4% had multiple episodes. Similarly, a prospective observational study conducted from September 2011 to September 2012 among 407 newborns also revealed that only 32.7% had multiple episodes.²²In current study mean (SD) age at which first episode of hypoglycaemia detected was 6.33(16.05) hours. In consistent with this Thinesh Kumar et al concluded that 31% of neonates had hypoglycaemia at 6 hours of life.¹⁷In addition to this a study has revealed that 21.8% had hypoglycaemia at first 6 hours of life.²²In line with these results during first 2 to 6 hours 8.33% had hypoglycaemia.²³Another study supported this and showed that episodes of hypoglycaemia occurred during first 24 hours of life.²⁰

Among the symptoms of hypoglycaemia 11.4% exhibited with jitteriness. Similarly a prospective observational study revealed that 11.9% had jitteriness.²⁴A study has reported that 7% had jitteriness.²⁰In contrast to this studies reported 55.5%, 48%, 37.5% and 41% respectively.^18,21,22,25Only 2.8% exhibited convulsions in current study. In contrast to this studies by Dashti et al, Babu et al, Somanathan et al and Nishikant et al reported 30%, 22.22%, 16.6% and 9.5% respectively.^19,21,24,25Among the symptoms of hypoglycaemia none had apnoeic spell. In consistent with this a study reported that none had apnoeic spell.¹⁸In contrast to this studies by Dashti et al, Babu et al and Nishikant et al showed 9.8%, 16.66% and 9.8% respectively.^19,21,25In current study only 8.5% exhibited lethargy as one of the symptoms of hypoglycaemia. Contradicting this some studies showed 64%, 19.05%, 58%, 40%17.8% and 25% respectively.^{18,21-23,25,26}

In current study there was no significant association between hypoglycaemia and neonates gender. In consistent with this a prospective descriptive study conducted also showed no significance = 0.72.²⁶In addition to this a study also showed non significance P = 0.714.²⁷In contrast to this a study has reported significant association.²²Prematurity had no significant association with hypoglycaemia. Similarly an observational study conducted at Skopje, Macedonia among 84 neonates also showed non significance.²⁸ In contrary to the above results some studies showed significant association P < 0.001, P = 0.005 and P = 0.022 respectively.^16,26,27 Small for gestation had significant association with hypoglycaemia. In consistent with this a study also revealed significant association P < 0.001.¹⁶Contradicting this a study showed nonsignificant.²⁶Large for gestation had no significant association with hypoglycaemia. Similarly a study also showed non significance.²⁶Contradicting this a study revealed significance P < 0.001.¹⁶Birth asphyxia had significant association with hypoglycaemia. In accordance with this a research also reported significance P = 0.02¹⁶In contrast to this a study showed non significance P = 1.000.²⁶ Birth weight showed significant association with hypoglycaemia. In consistent with this a study revealed significant association P = 0.003.²²

Among the maternal risk factors pregnancy induced hypertension had no significant association with hypoglycaemia. Similarly a study also showed non significance P = 0.801.²⁶Diabetes mellitus also not had significant association with hypoglycaemia which is similar to the findings of a study in which P = 1.000.²⁶Gestational diabetes had significant association with hypoglycaemia. In consistent with this some studies revealed significant association P = 0.006 and P < 0.001 respectively.^16,27Mode of delivery had no significant association with hypoglycaemia. Congruently research showed nonsignificance.¹⁶

The goal of treating hypoglycaemia is to prevent or to minimize brain injury by maintaining a glucose concentration above an acceptable threshold.²⁹A observational prospective study done among 299 exclusively breast-fed neonates reported that 20.06% were hypoglycemic.³⁰It has to be mentioned that extreme caution should exercised in generalizing the findings of the study to other populations because the current study was conducted in one region only. Similar study can be carried out with larger sample size. NICU nurses play a significant role in routine assessment of neonates in order to identify the risk factors of hypoglycaemia and to give prompt care.

Conclusion

The findings of this study showed that 30.4% of neonates had hypoglycaemia. At present the universal screening of neonates for hypoglycaemia is not recommended. The issue needs to be addressed as unrecognised hypoglycaemia may result in long term neurological sequelae.

Acknowledgments

The authors would like to express their gratitude to all the neonates who were enrolled in the study and also to their parents who have given informed consent.

Competing Interests

The authors declare no conflict of interest in this study.

Data Availability Statement

The datasets are available from the corresponding author on reasonable request.

Ethical Approval

The current study is a part of master of science in paediatric nursing thesis approved by Nursing Research Monitoring Committee (JIP/CON/NRMC/M.Sc./2020/PN/2) and Ethics Committee (JIP/CON/IEC/M.Sc./2020/PN/2).

Research Highlights

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