European Journal of Cardiovascular Medicine

Hypoglycemia is the most common metabolic abnormality in infancy and childhood. When prolonged or recurrent it is a potent cause of irreversible brain damage leading to cognitive impairment, recurrent seizure activity, cerebral palsy autonomic dysregulation1 however, when promptly diagnosed and supplemented these conditions can be prevented or minimized.

About 10-12% of Indian babies are born preterm <37 weeks as compared to 5-7% incidence in the west2. Birth weight and gestational age have traditionally been used as strong indicators of neonatal death3 .Preterm births are increasing globally because of fetal, placental and uterine causes and maternal and other causes.3 .The overall incidence of hypoglycemia in neonates varies from 0.2 to 11.4 %(2000). However in the presence of certain risk factor i.e. small for date , large for dates , infants of diabetic mother ,prematurity etc , the probability of hypoglycemia increases many fold .Late preterm is defined as birth between 34 0/7 weeks and 36 6/7 weeks of gestation calculated from the first day of mother's LMP4,5.

Late preterms were considered “Near Term" until recently and were treated on par with term infants .But they are physiologically and metabolically immature and have a higher risk of morbidity and mortality5,6,7).Late preterms account for approximately 70% of all preterm births and 8% of total births8.

Late preterm babies present with number of feeding challenges including fewer and shorter awake periods and excessive sleepiness. They tire easily during feeding, they have a weak suck and poor muscle tone and may exhibit an inability to sustain sucking and fatiguing easily before finishing a feed. Their tone may be adequate at the start of a feeding session but rapidly decreases during the feeding, indicating decreased endurance. There is a significant incidence of hypoglycemia in preterm and LBW babies inspite of being on breast feeds.9 .Late preterms are at higher risks for a number of problems including poor feeding, hypoglycemia, hypocalcemia, Jaundice, infections, respiratory distress, failure to thrive and hospital readmission (10)

There is still no research basis or consensus regarding the definition of neonatal hypoglycemia or who is at risk and under what circumstances or when screening should be performed 11,12 .It is the standard recommendation that babies weighing > 1.8 kg and above can be nursed alone by mother and do not need admission admission to NICU 13.These babies weighing 1.8 kg and above who are not asphyxiated ,who do not have any major congenital anomalies ,who are not obviously distressed, depressed or icteric at birth are roomed in with the mother immediately after birth and are examined once in 24 hrs. till discharge of the mother at postnatal ward are reviewed SOS when clinically abnormal signs and symptoms develop .The mothers after the delivery are counseled to frequently breastfeed the baby and keep the baby warm. This protocol is being followed since long and no study was carried out to see the effect of such a recommendation on the blood glucose values of the neonate and the ultimate outcome of these babies at discharge from hospital.

So this study tried to evaluate the incidence of hypoglycemia in late preterm appropriate for gestational age babies who were on breast feeding. It also tried to evaluate the effect of counseling mothers to frequently breast feed their babies, first feeding started as early at first hour of life, how far the counseling has been effective in making mothers breast feed their babies. Babies who developed hypoglycemia were initially treated with feeds and the protocol for management of neonatal hypoglycemia was followed.14

Aims and Objectives

1. To study the incidence of hypoglycemia in Late preterm babies who are on breastfeeds since birth
2. To study the need of regular blood glucose monitoring in early diagnosis of hypoglycemia in late preterm neonates.

This is a Hospital Based Observational study was conducted in the Department of Pediatrics, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka.

Plasma glucose levels were monitored for the late preterm neonates at 2, 6, 12, 24, 48 and 72 hours of life along with the symptoms at the onset of hypoglycemia using glucometer.

Following Criteria were used for assessing the neonates:

1.             Hypoglycemia was defined as Glucometer blood sugar reading of less than 40mg/dl.

2.             “Late preterm” is defined as infants born at gestational age between 34 0⁄7 weeks and 36 6⁄7 weeks calculated from the first day of mothers last menstrual period. (4,5)

Methodology

The study is done at hospital, a tertiary level hospital neonatal unit (Labour room, Premature unit, Postnatal ward ). A total of 120 consecutive late preterm babies appropriate weight for gestational age were monitored for glucose levels for this study. The babies which were not fitting into the inclusion and exclusion criteria are not considered for the study.

Informed consent from the parents was taken before monitoring the blood glucose levels. The mothers were counseled about the early and frequent breast feeding of the baby. When the hypoglycemia was noted, the level of glucose was assessed and managed according to the standard AIMS NICU protocols. The hypoglycemia was confirmed with the laboratory diagnosis.

A predesigned proforma prepared by the clinician was used to record information and the babies were assessed for occurrance of hypoglycemia against the sex of the baby, weight of the baby, age of onset, parity and age of mother, mode of delivery, gestational age and symptomatology.

Procedure : Samples were collected by heel prick (capillary blood). The glucose level was measured using Sugar-check active glucometer by touching the drop of blood collected to the curve at the edge of the strip .Blood will be drawn into the strip automatically. Do not place the drop of the blood on the top of the strip .The test will appear within 7 seconds.

Neonates with asymptomatic hypoglycemia with blood glucose level between 20 and 40 g/dl were breast fed and glucose was monitored. They were advised for frequent feeds. Babies with symptomatic hypoglycemia were given bolus of 2ml/kg 10% dextrose and were transferred to Neonatal Intensive Care Unit (NICU) and managed according to the standard protocol.

Inclusion Criteria:

1.       All late pre term babies born during a period of 1 year in hospital, delivered by normal vaginal and caesarian section

2.       Breast fed babies were taken up for this study.

Exclusion Criteria:

1.       Birth asphyxia

2.       Small for gestational age(SGA),

3.       Large for gestational age(LGA),

4.       Babies admitted in NICU,

5.       Multiple gestation babies,

6.       Babies who were started on formula feeds

7.       Parents who have not given consent.

8.       Babies discharged before 72hrs.

Statistical Analysis: The information collected regarding all the selected cases was noted in a predesigned proforma and entered in a Microsoft excel sheet. The Statistical analysis was done with the help of computer using SPSS 19.0 version software. Using this software range, frequencies and percentages are calculated for qualitative variables. Chi square and p values will also be calculated .p value less than 0.05 will denote the significant relationship.

A total of 120 late preterm babies were assessed. Of which, 61 were female and 59 were male babies. In our study, overall incidence of hypoglycemia was 15.83%. Majority of the hypoglycemia occurred on the first day (84.21%) and 2nd day(15.78%) with no episodes on third day of life (Table 4). Out of 19 hypoglycemic babies, 8(42.1%) were symptomatic, and 11(57.89%) were asymptomatic .In our study, hypoglycemia was slightly more in male babies (Table 3). Out of babies born to 82 multiparous mothers, hypoglycemia occured in 9 and out of babies born to 38 primiparous mothers 10 developed hypoglycemia (Table 5). Considering the mode of delivery, out of 53 babies born by normal vaginal route, 8 had hypoglycemia and in 67 caesarian born babies,11 had hypoglycemia.(Table 6).

Out of 19 hypoglycemic babies, 8(42.1%) belong to 34 weeks group,3(15.8%) in 35 weeks and 8(42.1%) belong to36 weeks(Table 7).In the above gestational age groups mentioned, the highest incidence of hypoglycemia was observed in 34 weeks of age . The incidence of hypoglycemia in babies born tho mother of <25 years is15.3% while babies of mothers >25 years is 16.7% (Table 8).Hypoglycemia occured more in babies weighing<2kg (52.9%) when compared to babies 2-2.5 kg and >2.5 kg babies(47.36%) (Table 9).

In our study, the incidence of hypoglycemia in late preterm newborns was 15.83% .In a study by Jaiswal et al , incidence was 8.8% in late preterms when compared to 1.4 % in term babies .They included late preterms and term babies to assess the early noenatal morbidity patterns .The blood sugars were monitored at 12 hourly intervals in all late preterm, IUGR (intrauterine growth restriction), IDM (Infant of diabetic mother) and LGA (Large for gestation, birth weight >2SD) infants. Low incidence of hypoglycemia in their study could be due to the difference in frequency of glucose monitoring .15

The incidence of hypoglycemia was 22% by Kalyani Srinivas et al 16 which was more when compared to the present study .In their study, all the babies with gestational age between 34 0/7 to 36 6/7 weeks admitted in NICU were observed till discharge or death and were followed up till one month of age. Mothers with medical problems like epilepsy, diabetes, hypertensive disorder, heart disease, and Pregnancy associated complications like PIH, oligohydramnios, antepartum hemorrhage, premature rupture of membranes were included. . Neonatal data included gestational age at birth, birth weight, mode of delivery, indication of elective birth, resuscitative measure at birth, Apgar scores, cause of NICU admission, progress during hospitalization, duration of hospital stay, mortality and its cause. Inclusion of all the high risk babies could have resulted in higher incidence of hypoglycemia.

In the present study hypoglycemia was seen in babies on day 1(84.2%) and day 2 of life with no occurrence during the later stage. In a study by MA Bhat et al 17 , the main objectives were to find the incidence and risk factors associated with development of hypoglycemia in small for gestational age (SGA) babies. This was a prospective longitudinal study.  The sample included SGA babies and study was done over a period of six months. 127 consecutively born small for gestational age babies were investigated prospectively for development of hypoglycemia in first 48 hrs of life. The overall incidence of hypoglycemia was 25.2% in SGA babies and 98% of the episodes occurred within first 24 hrs. and by Hawdon et al 18 almost all the episodes of hypoglycemia in SGA babies occurred within 24 hours. It is probably due to inclusion of only SGA babies.

But, in a study by K.Inayathullah khan et al and Singh et al, hypoglycemia was more common in male babies (19) which could be because their study samples included more number of male babies. Hypoglycemia was seen in 11(32.3%) preterm and 33(29%) term babies (p>0.05). The higher incidence of hypoglycemia in preterms may be due to his study group included all preterms (<37 weeks) with symptoms. Feeding difficulty was the most common symptom of hypoglycemia 32(72.7%) cases followed by jitteriness in 28(62.7%) cases. The sample included were all singleton neonates with signs and symptoms of hypoglycemia (seizures, jitteriness, lethargy, reluctant to feed, respiratory distress, hypotonia, hypothermia, abnormal cry, apnea and poor respiratory effort) presenting within 24 hours of birth .(Inayatullah) The incidence of hypoglycemia was more in babies born to primiparous mothers(26.3%) compared to babies born to multiparous (11%) which is correlating with study done by Purnima samayam et al where 23.07% of neonates born to primiparous mothers had hypoglycemia, against 5.4% neonates born to multiparous mothers 20.

Term, normal birth weight, healthy, CAN score 25 and above, asymptomatic singleton neonates delivered by vaginal route or LSCS were included. The study shows an incidence of hypoglycemia of 10% in first 24 hours of life in healthy, asymptomatic term neonates with normal CAN scores. This highlights that hypoglycemia occurs in a significant number of these exclusively breast fed neonates. This may be probably because primiparous mothers are the ones who face more difficulties related to breast feeding. Hence babies born to this group of mothers may be monitored more closely for hypoglycemia.

In the present study, the incidence of hypoglycemia was highest (29.6%) in the 34 weeks gestational age babies category and reduced to 12.5% in the 35 weeks category and 11.6% in the 36 weeks.

In the present study incidence is more in babies with weight < 2 kg when compared to babies with > 2 kg babies.In a study by Ishiguro A et al 21 where admissions due to hypoglycemia were 24.3% in 35 weeks and 14.1% in 36 weeks gestation(Birth weight>=2kg).There was no mention on babies of 34 week gestation babies .The incidence in 35 week age babies is more when compared to the present study the babies with problems were admitted. . The admission rates were mainly due to hypoglycemia with no cause other than prematurity hypoglycemia due to other causes accounted for fewer admissions. 22

The incidence of hypoglycemia is significant in late preterm babies. The incidence of asymptomatic hypoglycemia is much higher than symptomatic hypoglycemia. The highest incidence (84.2%) of hypoglycemia was noted in the first twenty four hours of life and 15.8% in next twenty four hours. Hence there is a need for monitoring blood glucose regularly in postnatal wards even in healthy late pre terms during the first 2 days of life. The hypoglycemia seen in babies with birth weight less than 2 kg was statistically significant. Babies of 34 weeks gestational age are vulnerable when compared to 35 and 36 weeks gestational age. There is a linear association of the hypoglycemia with gestational age. Hypoglycemia was more in babies born to primi mother when compared to multipara mothers.

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13.    KE Elizebeth,5th edi, Chapter Feeding of Low birth weight and preterm babies,p38)

14.    AIMS Protocols:2014,Chapter 17,hypoglycemia,p 216)

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