Towards improved neonatal care: Developing reference intervals for biochemical parameters in umbilical cord blood: An Indian study

Table 1 Sociodemographic and clinical characteristics of study participants

Information		Number of subjects	Percentage
Resident of	Mumbai	185	88.2
	Outside Mumbai	25	11.8
Parity	Non–primipara	152	72.4
	Primipara	58	27.6
Obstetric history1	Abortions	40	18.9
	No abortions	170	81.1
Delivery mode	Vaginal delivery	38	18.1
	C-Section delivery2	172	81.9
Sex of neonate	Male	112	53.5
	Female	98	46.5
Weight of neonate	2.5–3.0 kg	164	78
	Above 3 kg	46	22
Maternal age	< 35 years	199	95
	> or = 35 years	11	5
Gestational age of infant	Term (38-42 weeks)	170	81
	Before term	40	19

¹Abortion history implies spontaneous abortions only.

²C-Section delivery includes only elective or planned surgeries.

Table 2 Independent (2 Groups) Mann-Whitney U test (P values less than 0.05 determines the significance level) of selected Biochemical parameters by sex of infant, mode of delivery, age of mother and obstetrics history along with Median and P value

Parameters	P value			Median
	By sex	Mode of delivery	Obstetric history
Serum bilirubin (T)	0.9278	0.1305	0.1800	1.9
Serum bilirubin (D)	0.5564	0.2016	0.9971	0.3
Serum bilirubin (I)	0.3965	0.1461	0.5466	1.4
Serum creatinine	0.2804	0.7301	0.5292	0.56
Serum sodium	0.4030	0.0128	0.7638	136.3
Serum potassium	0.5892	0.0411	0.7086	5.085
Serum chloride	0.7847	0.1800	0.6612	106
Plasma glucose	0.8293	0.0039	0.8404	57.2

Table 3 Reference intervals for umbilical cord blood biochemical parameters by sex of the baby

Parameter	Sex	N	Median	Mean	Max	Min	Reference interval
							Lower limit	Upper limit
Serum bilirubin (T)	Male	112	1.85	1.824	3.2	0.25	0.509	3.139
	Female	98	1.8	1.834	3.17	0.3	0.687	2.981
	Combined	210	1.9	1.879	3.24	0.25	0.618	3.14
Serum bilirubin (D)	Male	112	0.3	0.318	0.6	0.1	0.095	0.541
	Female	98	0.3	0.326	0.6	0.1	0.095	0.565
	Combined	210	0.3	0.354	1.22	0.1	0.097	0.55
Serum bilirubin (I)	Male	112	1.16	1.159	1.8	0.2	0.7276	2.036
	Female	98	1.2	1.334	1.9	0.8	0.7234	1.944
	Combined	210	1.4	1.453	2.5	0.8	0.644	2.262
Serum creatinine	Male	112	0.55	0.492	0.65	0.32	0.248	0.736
	Female	98	0.545	0.515	0.67	0.31	0.282	0.748
	Combined	210	0.56	0.511	0.72	0.31	0.2677	0.755
Serum sodium	Male	112	137	136.075	142.3	137	129.392	142.76
	Female	98	136.2	135.51	142.6	124	127.03	143.99
	Combined	210	136.3	135.72	142.6	124	128.19	143.26
Serum potassium	Male	112	5.31	5.77	9.89	3.9	2.16	9.37
	Female	98	4.955	5.592	9.6	3.9	1.952	9.233
	Combined	210	5.085	5.797	15.41	3.9	1.62	9.98
Serum chloride	Male	112	106.1	105.94	113.3	97	99.65	112.23
	Female	98	106.65	106.08	111	97.8	100.65	111.52
	Combined	210	106	105.94	113.3	97	100.19	111.68
Plasma glucose	Male	112	55.6	59.74	91.8	33.4	17.85	101.62
	Female	98	59	59.073	94.8	42.1	34.742	83.4036
	Combined	210	57.2	59.49	94.8	31.6	24.75	94.23

Table 4 mean ± SD or median comparison with company derived values, other published reference values and peripheral venous blood with current study results

Parameter	PVB[19]	Current Study			China[17]	Korea[16]
	RI	RI	Median	Mean	Median	Mean
Direct bilirubin (mg/dL)	0.33–0.71	0.1-0.55	0.3	0.354	NA	NA
Indirect bilirubin (mg/dL)	NA	0.64-2.262	1.4	1.453	NA	NA
Total bilirubin (mg/dL)	0.19–16.6	0.62-3.14	1.9	1.879	NA	0.5
Creatinine (mg/dL)	0.32–0.92	0.27-0.76	0.56	0.511	NA	0.38
Chloride (mEq/L)	102–111	100.19-111.68	106	105.94	101	NA
Potassium (mEq/L)	3.7–5.9	1.62–9.98	5.085	5.797	4.05	NA
Sodium (mEq/L)	133–146	128.19-143.26	136.3	135.72	135	NA
Glucose (mg/dL)	30–60	24.75–94.23	57.2	59.49	NA	96.5

PVB: Peripheral venous blood; NA: Not available; RI: Reference interval.