Incidence and factors associated with neonatal hypoglycaemia in Chinese newborns delivered via caesarean section: a cross-sectional study

Abstract

Background

Neonatal hypoglycaemia is a common metabolic disorder in newborns and may be more frequent in infants delivered by caesarean section because of altered metabolic adaptation after birth. Evidence specific to Chinese caesarean-delivered newborns remains limited.

Objective

To determine the incidence of neonatal hypoglycaemia and identify factors associated with its occurrence in Chinese newborns delivered via caesarean section.

Design

Cross-sectional study.

Setting

Three regional obstetric care centres in East China.

Participants

A total of 1232 mother-newborn pairs, including both term and preterm singleton infants delivered via caesarean section.

Methods

Data were extracted from hospital electronic medical records. Neonatal hypoglycaemia was defined as a blood glucose level below 2.6 mmol/L within 24 hours after birth. Maternal, obstetric and neonatal characteristics were analysed. Bivariable analyses were performed to assess associations between neonatal hypoglycaemia and candidate variables, followed by multivariable logistic regression to identify independent factors. Predictive performance of the final model was evaluated using receiver operating characteristic analysis.

Results

Neonatal hypoglycaemia occurred in 800 of 1232 newborns, giving an incidence of 64.9% (95% CI 62.3% to 67.6%). In multivariable logistic regression, higher gestational age was independently associated with lower odds of neonatal hypoglycaemia (OR 0.781, 95% CI 0.684 to 0.891; p<0.001). Compared with appropriate-for-gestational-age newborns, large-for-gestational-age newborns had higher odds of hypoglycaemia (OR 2.200, 95% CI 1.477 to 3.276; p<0.001), whereas small-for-gestational-age newborns had lower odds (OR 0.394, 95% CI 0.188 to 0.824; p=0.013). Elective caesarean delivery was also associated with higher odds of hypoglycaemia (OR 1.638, 95% CI 1.248 to 2.150; p<0.001). Compared with parity 1, parity 3 was associated with higher odds of hypoglycaemia (OR 2.274, 95% CI 1.151 to 4.496; p=0.018), whereas parity 2 was not significant (OR 1.224, 95% CI 0.936 to 1.601; p=0.140). For amniotic fluid characteristics, category 1 was not significantly associated with hypoglycaemia (OR 0.624, 95% CI 0.287 to 1.359; p=0.235), whereas categories 2 and 3 were associated with lower odds (OR 0.478, 95% CI 0.291 to 0.786; p=0.004, and OR 0.518, 95% CI 0.296 to 0.909; p=0.022, respectively). The final model showed modest discrimination, with an area under the curve of 0.667 (95% CI 0.633 to 0.697).

Conclusions

Neonatal hypoglycaemia was common among Chinese newborns delivered via caesarean section, but most episodes were asymptomatic and resolved with routine feeding within 24 hours. Gestational age, fetal growth classification, elective caesarean delivery, parity and amniotic fluid characteristics were associated with hypoglycaemia in the current model. Early glucose monitoring and targeted nutritional support may be particularly important for newborns at increased risk.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• This study uses routine clinical data from multiple hospitals, providing a large and diverse sample of maternal and neonatal characteristics.

• The use of standardised protocols for data collection ensures consistency across the participating hospitals.

• This study relies on previously collected data, which may limit the ability to control for potential confounders not included in the original data collection.

• The lack of detailed feeding data limits the ability to assess the potential influence of feeding practices on neonatal hypoglycaemia.

Introduction

Neonatal hypoglycaemia is a common metabolic disorder in newborns, although its clinical definition and diagnostic threshold vary across countries, institutions and professional societies. A blood glucose threshold of 2.6 mmol/L is widely used to guide clinical intervention.¹,³ Previous studies have reported substantial variation in the prevalence of neonatal hypoglycaemia, ranging from 2.2% in general neonatal populations to as high as 27% in high-risk groups.⁴,⁶ If not identified and managed promptly, neonatal hypoglycaemia can lead to serious complications, including seizures, neurological injury and later developmental impairment.^{7 8}

Although the caesarean delivery rate in China has declined in recent years, it remains high. National data indicate an overall caesarean rate of 43.5%, with higher rates in public referral hospitals and private hospitals and substantial variation across hospital types.⁹ Caesarean delivery may interfere with early skin-to-skin contact and delay initiation of breastfeeding, both of which are important for stabilising neonatal blood glucose levels.¹⁰,¹⁴ Such disruptions may increase the risk of hypoglycaemia in infants delivered by caesarean section.

A clear understanding of the incidence and determinants of neonatal hypoglycaemia in caesarean-delivered newborns is important for developing targeted preventive strategies. Identification of population-specific risk factors may inform clinical practice and policy aimed at reducing hypoglycaemia and its complications and improving neonatal outcomes.

Existing evidence indicates that preterm infants are particularly vulnerable to neonatal hypoglycaemia, with reported rates of up to 33.7% among infants born before 33 weeks of gestation.¹⁵ Reported risk factors include lower gestational age, maternal diabetes, particularly gestational diabetes mellitus (GDM) and caesarean delivery.¹⁶,¹⁸ Additional factors such as delayed initiation of breastfeeding and abnormal birth weight, including both small for gestational age (SGA) and large for gestational age (LGA), may further increase risk.^{19 20} In contrast, later gestational age, antenatal magnesium sulfate administration and labour before delivery may reduce that risk.^{15 21 22}

Research focusing specifically on Chinese newborns delivered by caesarean section remains limited. Most published studies have examined broader neonatal populations or populations from other countries, and findings from such settings may not fully reflect the clinical practices, maternal characteristics and feeding patterns seen in China. Population-specific evidence is needed to support more precise and contextually relevant clinical decision-making. Accordingly, this study aimed to determine the incidence of neonatal hypoglycaemia and identify maternal, neonatal and delivery-related factors associated with its occurrence in Chinese newborns delivered via caesarean section.

The findings may help improve neonatal care by informing early screening and intervention protocols, guiding counselling for women undergoing caesarean delivery and contributing to the development of clinical guidance tailored to the Chinese population. In addition, the results may inform healthcare policy and resource allocation by supporting better training of healthcare providers and more targeted support for newborns at elevated risk. Addressing such challenges may improve outcomes for caesarean-delivered newborns and reduce the long-term burden associated with neonatal hypoglycaemia.

Methods

Design

This cross-sectional study was conducted to determine the incidence of neonatal hypoglycaemia and identify factors associated with its occurrence in Chinese newborns delivered via caesarean section.

Setting and sample

The current study was conducted at three regional obstetric care centres in East China. Data were collected from 1 January 2024 to 31 December 2024 using consecutive sampling. Urine acetone and fasting blood glucose were measured as part of routine maternal care at the participating hospitals according to institutional protocols. Fasting was defined as no food or drink for at least 8 hours before measurement.

Eligible participants were singleton newborns delivered by caesarean section during the study period, including both term infants (≥37 weeks of gestation) and preterm infants (<37 weeks of gestation), who underwent routine blood glucose monitoring within 24 hours after birth. Newborns of mothers with pregestational diabetes were excluded because of the potential for substantial confounding. Pregestational diabetes was defined consistently across all participating hospitals as a documented diagnosis of type 1 or type 2 diabetes mellitus before conception in the medical record. Newborns of mothers with severe maternal hypertension were also excluded. Severe maternal hypertension was defined as a documented systolic blood pressure≥160 mm Hg and/or diastolic blood pressure≥110 mm Hg during the index admission or a physician-documented diagnosis of severe hypertensive disorder requiring urgent treatment. No other non-standardised maternal comorbidity categories were used as exclusion criteria.

Data sources, collection and management

Data were extracted from the electronic medical record systems of the participating hospitals. To ensure consistency and data quality, all researchers involved in data collection received training in standardised medical record review procedures. Data extraction was performed using a standardised medical record review form. Any discrepancies identified during the initial extraction process were resolved by discussion between the two reviewers with reference to the source electronic medical record. To assess extraction accuracy, after the full eligible dataset had been assembled, 10% of records were selected using a computer-generated simple random sampling procedure and independently re-extracted by a second reviewer. The original and repeated extractions were compared variable by variable. When discrepancies were identified, the source record was rechecked and the final value was determined by consensus; if consensus could not be reached, a senior investigator adjudicated the final entry.

To protect confidentiality, all data were de-identified before analysis by replacing personal identifiers with unique study codes. The linkage file containing identifiers was stored separately from the analytic dataset. Access to the dataset was restricted to authorised researchers, and all files were stored on a password-protected hard drive with double backup.

Variables and measurements

Outcome variable

The primary outcome was neonatal hypoglycaemia, defined as a blood glucose level below 2.6 mmol/L within the first 24 hours of life. The 2.6 mmol/L threshold was selected because it is widely used in international clinical guidance and practice.

Blood glucose levels were measured using fingertip blood testing devices that were used routinely and uniformly across the participating hospitals. Although heel-prick sampling is more commonly recommended in neonatal practice, fingertip testing was used in this setting in accordance with local institutional practice. Blood glucose measurement was performed as part of routine care in neonatal units.

Independent variables

Independent variables included maternal, obstetric and neonatal characteristics. Maternal variables included age, body mass index (BMI), urine acetone level, fasting plasma glucose before labour and GDM-related glucose status. Obstetric variables included parity, type of caesarean delivery (elective or emergency), duration of labour, dexamethasone administration before labour and glucose or insulin administration during labour. Neonatal variables included gestational age, birth weight, fetal growth classification as appropriate for gestational age (AGA), LGA or SGA, 1 min Apgar score, sex and amniotic fluid characteristics.

Data analysis

Descriptive statistics were used to summarise maternal, obstetric and neonatal characteristics. Continuous variables were presented as means and SD, and categorical variables were reported as frequencies and percentages.

Bivariable analyses were performed to assess associations between neonatal hypoglycaemia and candidate independent variables. For categorical variables, χ² tests or Fisher’s exact tests were used, as appropriate. For continuous variables, comparisons were performed using parametric or non-parametric tests according to data distribution. Variables with p<0.05 in the bivariable analyses were entered into a multivariable logistic regression model to identify factors independently associated with neonatal hypoglycaemia. Results were reported as ORs with 95% CIs.

A receiver operating characteristic (ROC) curve was constructed to assess the predictive performance of the final multivariable model, and the area under the curve (AUC) was used to evaluate discrimination.

All analyses were performed using SPSS V.26.0 (IBM Corp., Armonk, New York, USA). A two-sided p value of <0.05 was considered statistically significant.

Use of ChatGPT

ChatGPT (OpenAI, San Francisco, USA) was used to translate the original Chinese manuscript into English and to assist with language editing during revision. It was not involved in the conceptualisation or design of the current study, data collection, data analysis, initial drafting of the manuscript or critical scientific revision.

Patient and public involvement

None.

Results

Demographic and clinical characteristics

Table 1 provides an overview of the demographic and clinical characteristics of the 1232 mother–newborn pairs included in the current study. The average maternal age was 31.8 years (SD=4.34), with a mean parity of 1.66 (SD=0.60). The mean maternal weight was 72.82 kg (SD=11.27), and the average maternal height was 1.60 m (SD=0.10), resulting in a mean BMI of 29.01 (SD=16.05).

Table 1. Demographic and clinical characteristics of mothers and new (N=1232).

Characteristic	Mean±SD	n	%	95% CI
Mother’s characteristics
Age	31.8±4.34 years
Parity	1.66±0.60
1		500	40.6
2		664	53.9
3		60	4.9
4		8	0.6
Weight	72.82±11.27 kg
Height	1.60±0.10 m
BMI	29.01±16.05
Urine acetone
Negative		840	68.2
1+		96	7.8
2+		148	12.0
3+		88	7.1
4+		60	4.9
Elevated OGTT before labour		492	39.9
1 hour after delivery		500	40.6
2 hours after delivery		560	45.5
FPG before labour		184	14.9
Lab test results
D-dimer	2.06±0.74
ALB	35.9±3.11
TAG	3.79±2.04
LDL	2.72±0.886
CHOL	6.00±1.48
Glu	4.30±0.70
Medication
DXM before labour		200	16.2
Dose (mg)	7.50±3.54
Interval between DXM and end of labour (hours)	5.50±2.12
Glucose IV		220	17.9
Dose (g)	37.5±17.68
Interval between glucose IV and completion of labour (hours)	6.00±7.07
Insulin addition in glucose IV		184	14.9
Dose	8.00±5.66
Interval between insulin in glucose IV and completion of labour (hours)	6.00±7.07
Subcutaneous insulin injection		40	3.2
Length of labour (hours)	12.32±7.76
Type of procedure
Emergency caesarean		444	36.0
Elective caesarean		788	64.0
Newborn characteristics
Blood glucose within 24 hours of life (mmol/L)	3.30±0.85
<2.6		800	64.9	62.27% to 67.60%
Gestational age, week	Median=37.97			37.96 to 38.18
Birth weight, g	3420±551.54			3389.20 to 3450.80
Fetal growth classification
AGA		992	80.5	78.29% to 82.71%
LGA		208	16.9	14.81% to 19.00%
SGA		32	2.6	1.71% to 3.49%
Apgar score (1 min)
7		4	0.3
8		24	1.9
9		20	1.6
10		1184	96.1	95.02% to 97.18%
Gender
Female		572	46.4
Male		660	53.6
Amniotic fluid characteristics
0		1076	87.3
–1		28	2.3
–2		72	5.8
–3		56	4.5
Readmission		132	10.7

AGA, appropriate for gestational age; ALB, albumin; BMI, body mass index; CHOL, cholesterol; DXM, dexamethasone; FPG, fasting plasma glucose; Glu, glucose; IV, intravenous; LDL, low-density lipoprotein; LGA, large for gestational age; OGTT, oral glucose tolerance test; SGA, small for gestational age; TAG, triglyceride.

For maternal metabolic indicators, 68.2% of mothers had no detectable urine acetone (840/1232), and 31.8% tested positive, with varying degrees of positivity (1+ to 4+). The oral glucose tolerance test (OGTT) results before labour revealed that 39.9% (492/1232) of mothers had elevated glucose levels. At 1 hour after labour, 40.6% (500/1232) of mothers showed elevated glucose levels, and 45.5% (560/1232) showed elevated levels 2 hours after labour. Fasting plasma glucose (FPG) before labour was elevated in 14.9% (184/1232) of mothers.

For newborns, the incidence of neonatal hypoglycaemia was 64.9% (800/1232) (95% CI 62.27% to 67.60%). Among the 800 newborns with hypoglycaemia, 20.0% were symptomatic, most commonly presenting with feeding difficulties or lethargy, whereas 80.0% were asymptomatic at the time of detection. Most hypoglycaemic episodes were transient and resolved within the first 24 hours with routine feeding interventions. Blood glucose measurements were taken at regular intervals within 24 hours of birth, following the institutional protocol. The median gestational age was 37.97 weeks, with a 95% CI of 37.96 weeks to 38.18 weeks. The mean birth weight was 3420 g (SD=551.54), with a 95% CI of 3389.20 g to 3,450.80 g.

Regarding fetal growth classification, 80.5% (992/1232) of the neonates were classified as AGA (95% CI 78.29% to 82.71%), 16.9% (208/1232) were classified as LGA (95% CI 14.81% to 19.00%) and 2.6% (32/1232) were SGA (95% CI 1.71% to 3.49%). Finally, 96.1% (1,184/1232) of neonates had an Apgar score of 10, with a 95% CI of 95.02% to 97.18%.

Bivariable analysis

In the bivariable analyses, maternal age, BMI, urine acetone status, elevated OGTT before labour, elevated fasting plasma glucose before labour, dexamethasone administration before labour, glucose intravenous (IV) administration during labour, insulin addition in glucose IV, subcutaneous insulin injection and length of labour were not significantly associated with neonatal hypoglycaemia. In contrast, parity, type of caesarean delivery, gestational age, fetal growth classification and amniotic fluid characteristics were significantly associated with neonatal hypoglycaemia (table 2). The incidence of hypoglycaemia was higher among newborns delivered by elective caesarean section than among those delivered by emergency caesarean section (71.3% (562/788) vs 53.6% (238/444), χ²=38.372, p<0.001). Hypoglycaemic newborns had a lower gestational age than normoglycaemic newborns (median 38.67 vs 39.16 weeks, Z=4.520, p<0.001). LGA newborns accounted for a greater proportion of hypoglycaemic cases than normoglycaemic cases (21.5% vs 8.3%; χ²=37.686, p<0.001), whereas SGA newborns were less frequent in the hypoglycaemia group (1.9% vs 3.9%). Abnormal amniotic fluid characteristics were less common among hypoglycaemic newborns than among normoglycaemic newborns (χ²=17.733, p<0.001).

Table 2. Bivariable analysis of factors associated with neonatal hypoglycaemia.

Variable	Normal glucose (n=432)	Hypoglycaemia (n=800)	Test statistic	P value
Maternal age, years	31.6±4.29	31.9±4.37	t=−1.12	0.263
BMI, kg/m2	28.7±15.8	29.2±16.2	t=−0.53	0.596
Urine acetone			χ2=3.84	0.428
Negative	304 (70.4%)	536 (67.0%)
1+	30 (6.9%)	66 (8.3%)
2+	46 (10.6%)	102 (12.8%)
3+	28 (6.5%)	60 (7.5%)
4+	24 (5.6%)	36 (4.5%)
Elevated OGTT before labour	164 (38.0%)	328 (41.0%)	χ2=1.05	0.306
FPG before labour elevated	58 (13.4%)	126 (15.8%)	χ2=1.23	0.267
Dexamethasone before labour	66 (15.3%)	134 (16.8%)	χ2=0.46	0.498
Glucose IV administration during labour	72 (16.7%)	148 (18.5%)	χ2=0.64	0.423
Insulin addition in glucose IV	60 (13.9%)	124 (15.5%)	χ2=0.57	0.449
Subcutaneous insulin injection	12 (2.8%)	28 (3.5%)	Fisher’s exact	0.491
Length of labour, hours	11.9±7.5	12.5±7.9	t=−1.31	0.191
Parity			χ2=20.04	<0.001
1	209 (48.4%)	291 (36.4%)
2	208 (48.1%)	456 (57.0%)
3	12 (2.8%)	48 (6.0%)
4	3 (0.7%)	5 (0.6%)
Type of caesarean delivery			χ2=38.37	<0.001
Emergency	206 (47.7%)	238 (29.8%)
Elective	226 (52.3%)	562 (70.2%)
Gestational age, weeks	39.16 (IQR 38.43 to 39.86)	38.67 (IQR 38.14 to 39.14)	Z=4.52	<0.001
Fetal growth classification			χ2=37.69	<0.001
AGA	379 (87.7%)	613 (76.6%)
LGA	36 (8.3%)	172 (21.5%)
SGA	17 (3.9%)	15 (1.9%)
1 min Apgar score			Fisher’s exact	0.118
7	3 (0.7%)	1 (0.1%)
8	10 (2.3%)	14 (1.8%)
9	10 (2.3%)	10 (1.3%)
10	409 (94.7%)	775 (96.9%)
Infant sex			χ2=0.62	0.431
Female	195 (45.1%)	377 (47.1%)
Male	237 (54.9%)	423 (52.9%)
Amniotic fluid characteristics			χ2=17.73	<0.001
0	354 (81.9%)	722 (90.2%)
1	13 (3.0%)	15 (1.9%)
2	36 (8.3%)	36 (4.5%)
3	29 (6.7%)	27 (3.4%)

Data are presented as mean±SD, median (IQR) or n (%), as appropriate.

AGA, appropriate for gestational age; BMI, body mass index; FPG, fasting plasma glucose; IV, intravenous; LGA, large for gestational age; OGTT, oral glucose tolerance test; SGA, small for gestational age.

Multivariable logistic regression analysis

Variables that were significant in the bivariable analyses were entered into the multivariable logistic regression model. Higher gestational age was independently associated with lower odds of neonatal hypoglycaemia (OR 0.781, 95% CI 0.684 to 0.891; p<0.001). Compared with AGA newborns, LGA newborns had significantly higher odds of hypoglycaemia (OR 2.200, 95% CI 1.477 to 3.276; p<0.001), whereas SGA newborns had lower odds of hypoglycaemia (OR 0.394, 95% CI 0.188 to 0.824; p=0.013). Elective caesarean delivery was also associated with higher odds of neonatal hypoglycaemia (OR 1.638, 95% CI 1.248 to 2.150; p<0.001). Compared with parity 1, parity 2 was not significantly associated with hypoglycaemia (OR 1.224, 95% CI 0.936 to 1.601; p=0.140), whereas parity 3 was associated with higher odds (OR 2.274, 95% CI 1.151 to 4.496; p=0.018). Amniotic fluid characteristic 1 was not significantly associated with hypoglycaemia (OR 0.624, 95% CI 0.287 to 1.359; p=0.235), but characteristics 2 and 3 were associated with lower odds of hypoglycaemia (OR 0.478, 95% CI 0.291 to 0.786; p=0.004, and OR 0.518, 95% CI 0.296 to 0.909; p=0.022, respectively) (table 3).

Table 3. Multivariable logistic regression analysis of factors associated with neonatal hypoglycaemia.

Factor	B	P value	OR	95% CI
Parity 1	Reference
Parity 2	0.202	0.14	1.224	0.936 to 1.601
Parity 3	0.822	0.018	2.274	1.151 to 4.496
Parity 4	−0.279	0.72	0.757	0.165 to 3.473
Elective caesarean delivery	0.494	<0.001	1.638	1.248 to 2.150
Gestational age, weeks	−0.247	<0.001	0.781	0.684 to 0.891
AGA	Reference
LGA	0.788	<0.001	2.2	1.477 to 3.276
SGA	−0.931	0.013	0.394	0.188 to 0.824
Amniotic fluid characteristic 0	Reference
1	−0.471	0.235	0.624	0.287 to 1.359
2	−0.738	0.004	0.478	0.291 to 0.786
3	−0.657	0.022	0.518	0.296 to 0.909

AGA, appropriate for gestational age; LGA, large for gestational age; SGA, small for gestational age.

ROC curve analysis

ROC curve analysis showed that the final multivariable model had an AUC of 0.667 (95% bootstrap CI 0.633 to 0.697), indicating modest discrimination for predicting neonatal hypoglycaemia (figure 1).

Figure 1. Receiver operating characteristic curve of the multivariable logistic regression model for neonatal hypoglycaemia (n=1232). The model showed modest discriminative ability, with an area under the curve (AUC) of 0.667 (95% bootstrap CI 0.633 to 0.697).

Discussion

The high incidence of neonatal hypoglycaemia (64.9%) in Chinese newborns delivered via caesarean section may be attributable to a multifactorial interplay among delivery mode, neonatal metabolic adaptation and maternal health conditions. Caesarean delivery can disrupt the physiological transition of newborns to extrauterine life, particularly with respect to glucose homeostasis.^{22 23} Unlike vaginal birth, in which labour-induced stress hormones facilitate glycogenolysis and gluconeogenesis,²⁴ caesarean section may bypass part of this adaptive mechanism. The absence of such hormonal surges may predispose neonates to impaired glucose regulation.

An important clinical finding in the current study is that only one fifth of newborns with hypoglycaemia were symptomatic, whereas most affected newborns were asymptomatic and improved with routine feeding within 24 hours. This suggests that the high incidence observed in the present study largely reflected biochemical hypoglycaemia identified through routine monitoring rather than uniformly severe clinical compromise. This distinction is important for practice. The findings support the value of early glucose surveillance and prompt feeding support in caesarean-delivered newborns, while also indicating that incidence estimates based on screening thresholds should not be interpreted as meaning that most cases are clinically severe.

During caesarean section, especially under anaesthesia, mothers may receive intravenous glucose solutions. Excess glucose can cross the placenta, leading to fetal hyperglycaemia and subsequent fetal hyperinsulinaemia. After birth, the abrupt cessation of maternal glucose supply may result in neonatal hypoglycaemia because insulin levels remain elevated in the neonate.²⁵ In addition, caesarean delivery may delay the initiation of breastfeeding, which is a critical source of glucose for the newborn. This delay may further increase the risk of hypoglycaemia if the neonate does not receive adequate nutrition immediately after birth.¹⁸

The analysis identified gestational age and fetal growth as significant predictors of neonatal hypoglycaemia. Preterm infants showed a higher risk because of immature hepatic glycogen stores and underdeveloped counter-regulatory hormonal responses.²⁶ The increased incidence among LGA newborns is consistent with the well-documented association between maternal hyperglycaemia and fetal hyperinsulinism.²⁷ Elevated fetal insulin levels, which develop as a compensatory response to maternal hyperglycaemia, may persist after birth and lead to rapid glucose depletion.¹⁷

Maternal factors, particularly GDM, may also contribute to neonatal hypoglycaemia. Nearly 40% of mothers in this cohort had elevated OGTT results before delivery, suggesting suboptimal glycaemic control. Although pregestational diabetes was excluded from the analysis, its absence may have led to an underestimation of the true incidence of neonatal hypoglycaemia in this population. Dexamethasone administration has been reported to influence neonatal glucose regulation in some settings, but no significant association was observed in the current bivariable analysis.²⁸

Cultural and systemic factors, such as limited breastfeeding support and scheduled deliveries, may further distinguish the Chinese clinical context. Similar findings have been reported in other populations in which elective caesarean section has been associated with an increased risk of neonatal hypoglycaemia because of the absence of labour-associated hormonal priming.²⁹

The multivariate logistic regression analysis identified gestational age and fetal growth classification as independent predictors of neonatal hypoglycaemia. This finding is consistent with the existing literature, although some differences should be noted. Lower gestational age was associated with a higher risk, in line with previous studies showing that preterm infants are particularly vulnerable because of immature hepatic glucose production, limited glycogen reserves and insufficient counter-regulatory hormone secretion.³⁰,³³ Earlier research has shown that neonates born before 37 weeks of gestation are at particularly high risk of hypoglycaemia.²⁹ However, some studies have reported that late-preterm infants (34–36 weeks) may not have significantly higher hypoglycaemia rates than term infants when early feeding is established adequately.³⁴ This discrepancy may reflect differences in feeding protocols, glucose monitoring frequency or maternal metabolic status across settings, and suggests that future studies should examine whether systematic early feeding interventions could reduce hypoglycaemia risk in this group.

The analysis also showed that LGA newborns had a significantly higher risk of neonatal hypoglycaemia, a finding that is strongly supported by previous studies linking fetal overgrowth to neonatal metabolic instability.^{35 36} LGA infants, particularly those born to mothers with GDM, often develop fetal hyperinsulinaemia because of prolonged in utero exposure to elevated glucose levels.³⁷ This increased insulin response may persist after birth, leading to rapid glucose consumption and hypoglycaemia following umbilical cord clamping.

However, the lack of a significant association between SGA status and neonatal hypoglycaemia differs from earlier research, which has identified SGA infants as a high-risk group because of reduced glycogen stores and impaired counter-regulatory hormonal responses.³⁸ Although some studies have reported hypoglycaemia rates of up to 67% in preterm SGA neonates,³⁹ the absence of a significant association in the present analysis may reflect differences in postnatal feeding practices or the relatively low proportion of severely growth-restricted infants in this cohort.

In the current analysis, elective caesarean delivery remained significantly associated with neonatal hypoglycaemia in the multivariable model, suggesting that the observed association was not explained fully by differences in gestational age, fetal growth classification, parity or amniotic fluid characteristics. Elective caesarean delivery was associated with a higher incidence of neonatal hypoglycaemia than emergency caesarean delivery, a pattern that has also been reported in previous studies.^{29 40} This finding is clinically plausible because elective caesarean delivery often occurs in the absence of labour-associated hormonal priming, which may reduce the neonatal counter-regulatory response required for early postnatal glucose adaptation. In addition, scheduled caesarean delivery may be associated with longer maternal fasting periods and delayed initiation of breastfeeding, both of which could contribute to lower neonatal glucose levels after birth.

Although the present study could not fully disentangle the relative contributions of maternal fasting duration, intrapartum glucose management and early feeding practices, the persistence of the association in the adjusted model suggests that elective caesarean delivery may represent a useful clinical marker for increased surveillance. Future studies should examine whether optimising preoperative fasting policies and postnatal feeding support can reduce hypoglycaemia risk in newborns delivered by elective caesarean section.

Some studies have suggested that fasting periods longer than 8–12 hours before surgery may contribute to lower neonatal blood glucose levels, particularly in settings with high caesarean section rates. This issue is especially relevant where preoperative fasting guidelines remain conservative and women are required to fast for extended periods even before scheduled procedures. Given this context, revisiting fasting protocols for elective caesarean delivery, such as permitting carbohydrate-containing clear fluids closer to the time of delivery, may represent a practical strategy to reduce the risk of neonatal hypoglycaemia. Future research should examine whether modifying maternal fasting duration or implementing targeted glucose monitoring strategies in elective caesarean deliveries can reduce neonatal hypoglycaemia, particularly in high-risk groups such as LGA and preterm infants.

Strengths and limitations

The strengths of this study include the relatively large sample size and the use of multivariable analysis to identify independent predictors of neonatal hypoglycaemia. By focusing on Chinese newborns delivered via caesarean section, this work provides useful insight into region-specific risk factors and adds to the existing literature. The inclusion of both elective and emergency caesarean deliveries also allowed assessment of procedural influences. However, several limitations should be acknowledged. First, the cross-sectional design precludes causal inference. Second, variation in feeding practices and glucose monitoring protocols across hospitals may have influenced the results. Third, although some maternal treatment variables were recorded in the medical records, not all clinically relevant exposures could be fully evaluated in sufficient detail, including the timing and context of intrapartum glucose administration, dexamethasone exposure and neonatal feeding characteristics such as timing, frequency and type of feed. Those factors are physiologically relevant to neonatal glucose regulation and may have contributed to residual confounding. Future studies should examine longer-term outcomes and evaluate the effectiveness of targeted interventions for at-risk neonates. The current study used a glucose cut-off of 2.6 mmol/L, which is widely applied in clinical practice. However, other literature has suggested a lower threshold of 1.6 mmol/L for infants within the first 24 hours of life.^{41 42} Use of the 2.6 mmol/L cut-off might therefore have led to overdiagnosis of neonatal hypoglycaemia and possibly unnecessary clinical intervention.

Conclusions

Neonatal hypoglycaemia defined by a blood glucose level below 2.6 mmol/L occurred frequently among Chinese newborns delivered via caesarean section. However, only a minority of affected newborns were symptomatic, and most episodes resolved with routine feeding within the first 24 hours, suggesting that many cases were transient and clinically mild when detected early. Lower gestational age, LGA status, elective caesarean delivery, parity and amniotic fluid characteristics were associated with hypoglycaemia in the current model. These findings support targeted glucose monitoring and early nutritional management, particularly for newborns at increased risk, while highlighting the need to interpret screening-detected hypoglycaemia in light of symptom status and early clinical course.

Data availability statement

Data are available upon reasonable request.