Meconium-stained amniotic fluid (MSAF) is a common intrapartum finding, defined by the presence of fetal bowel contents in the amniotic fluid.[1] Composed of water, bile acids, intestinal secretions, desquamated cells, and other gastrointestinal components, meconium is typically passed postnatally within the first 24 hours of life in healthy term neonates.[2] However, its passage in utero—especially prior to 37 weeks of gestation—is often considered abnormal and may indicate underlying fetal compromise.[2] MSAF is predominantly encountered in term and post-term pregnancies, with an incidence ranging from 12% to 16%, increasing to approximately 30% in post-dated pregnancies beyond 42 weeks.[3] Physiologically, meconium is retained in the fetal gastrointestinal tract due to absent peristalsis and sustained anal sphincter tone.[3] Intrauterine passage may occur in response to increased intestinal peristalsis associated with fetal maturity, or due to pathological mechanisms such as fetal hypoxia, maternal hypertension, umbilical cord compression, or intrauterine infections. The presence of MSAF is clinically significant, as it is frequently associated with adverse perinatal outcomes, including meconium aspiration syndrome (MAS), perinatal asphyxia, neonatal sepsis, and the need for NICU admission.[4] These complications are more pronounced when the meconium is thick, viscous, and particulate, which increases the risk of respiratory obstruction and pulmonary inflammation if aspirated during labour or delivery.[5] The clinical management of pregnancies complicated by MSAF presents several challenges, particularly regarding the optimal mode of delivery. While normal vaginal delivery (NVD) is less invasive and associated with faster maternal recovery, it may expose the neonate to prolonged contact with meconium, increasing the risk of aspiration.[6,7] Conversely, lower segment caesarean section (LSCS) may offer a more controlled delivery environment, especially in cases of fetal distress, but is associated with higher maternal morbidity, surgical complications, and healthcare resource utilisation.[8] Furthermore, the consistency of meconium—thin versus thick—adds another dimension to clinical decision-making, with thick meconium being more frequently linked to severe neonatal outcomes and often influencing the choice in favour of caesarean delivery.[9] In India, particularly in rural healthcare settings, the management of MSAF is complicated by infrastructural limitations, delayed antenatal care, and inconsistent adherence to clinical protocols. There is a paucity of prospective, hospital-based studies systematically evaluating the influence of meconium consistency and mode of delivery on immediate neonatal outcomes. This study was therefore undertaken to evaluate and compare the immediate clinical outcomes of neonates born with MSAF delivered by NVD and LSCS.

Study Design: This was a single-centre, hospital-based, comparative, prospective observational study with a 1:1 group ratio. Study Setting: The study was conducted in the Department of Paediatrics at Amaltas Institute of Medical Sciences, Dewas, Madhya Pradesh, a tertiary care teaching hospital. Ethical Clearance: Ethical approval was granted by the Institutional Ethics Committee of Amaltas Institute of Medical Sciences, Dewas. Study Duration: 18 months. Primary outcomes: i. Neonatal condition assessed by APGAR scores at 1 minutes ii. Respiratory distress evaluated using Modified Downe’s Score Measurement of the Outcome • APGAR Score (0–10): Assessed at 1 and 5 minutes post-delivery. • Modified Downe’s Score: Assessed within the first 24 hours for respiratory distress. • MAS and Perinatal Asphyxia: Diagnosed clinically and radiologically per standard criteria. • NICU admission: Recorded based on the requirement of advanced neonatal support. Definition of the Exposure: Presence of MSAF, classified as: a. Thick MSAF: Viscous, particulate b. Thin MSAF: Diluted, less concentrated Mode of delivery (NVD vs LSCS) was analysed as a key associated factor. Study Participants: Neonates born to mothers with MSAF (≥37 weeks gestation) during the study period. Inclusion Criteria • Neonates born at ≥37 weeks gestation • Singleton pregnancies with cephalic presentation • MSAF observed after spontaneous or artificial rupture of membranes Exclusion Criteria • Preterm deliveries (<37 weeks) • Non-cephalic presentations (e.g., breech) • Twin pregnancies • Known congenital anomalies Sample Size: Based on a prevalence (p) of 14% MSAF in term deliveries, 95% CI, 5% error margin: n = 1.96² × 0.14 × (1−0.14) / 0.05² ≈ 186, rounded to 200. Sampling Methodology: Non-probability convenience sampling was used, including all eligible MSAF cases during the study period. Allocation to Groups: Participants were grouped based on mode of delivery: • Group V: Neonates delivered vaginally • Group C: Neonates delivered via caesarean section Participant Recruitment: Recruitment was done by the Principal Investigator in collaboration with obstetric and paediatric teams. Screening for eligibility was performed upon admission to labour ward. Obtaining Informed Consent: Written informed consent was obtained in bilingual format (Hindi/English) after explaining the study, its risks, and voluntary nature. Participants retained a copy. Data Collection Procedure: The data collection procedure for this study was conducted in a systematic and phased manner to ensure completeness, accuracy, and uniformity in recording clinical information. The process began with the identification of meconium-stained amniotic fluid (MSAF) at the time of delivery. The consistency of the meconium was categorised as either thin or thick, based on visual assessment by the attending obstetric team. Thin meconium was defined as diluted, lightly stained amniotic fluid, whereas thick meconium appeared dense, particulate, and greenish in colour, often obscuring the view of the foetus during delivery. Following the detection of MSAF, the mode of delivery was recorded for each case—either normal vaginal delivery (NVD) or lower segment caesarean section (LSCS). This information was documented immediately post-delivery along with details of any intrapartum interventions, such as instrumental assistance or emergency surgical conversion. Each neonate was clinically evaluated using the APGAR scoring system at 1 and 5 minutes after birth. The APGAR score, which assesses Appearance, Pulse, Grimace, Activity, and Respiration, served as a rapid indicator of the neonate’s immediate postnatal condition. A score below 7 at 1 or 5 minutes was considered suggestive of neonatal compromise, prompting further evaluation and intervention as needed. Within the first 24 hours of life, neonates were further assessed for respiratory distress using the Modified Downe’s Score. This score evaluates the severity of respiratory symptoms based on parameters such as chest retractions, nasal flaring, cyanosis, and grunting. A score greater than 4 indicated moderate to severe distress, necessitating respiratory support and close monitoring. Neonates were then monitored continuously for 48 to 72 hours post-delivery for the development of complications associated with MSAF, such as Meconium Aspiration Syndrome (MAS) and perinatal asphyxia. MAS was diagnosed based on clinical presentation (tachypnoea, grunting, chest retractions) and radiological findings on chest X-ray. Perinatal asphyxia was considered in cases with persistently low APGAR scores, signs of multi-organ hypoxia, or metabolic acidosis. Wherever indicated, neonates were admitted to the Neonatal Intensive Care Unit (NICU) for advanced management. The need for NICU admission was documented along with the duration of stay, interventions administered (e.g., oxygen therapy, CPAP, mechanical ventilation), and treatment outcomes. All clinical data were recorded in a structured proforma and reviewed daily by the Principal Investigator to ensure consistency and data integrity. Statistical Analysis Plan: Data were analysed using Stata version 17.0. Descriptive statistics were expressed as mean ± standard deviation for continuous variables and as frequencies and percentages for categorical variables. For inferential analysis, Student’s t-test was applied to compare normally distributed continuous variables, while the Mann–Whitney U test was used for non-normally distributed variables. Associations between categorical variables were examined using the Chi-square test, and Pearson’s correlation coefficient was employed to assess linear relationships between continuous variables. A p-value of less than 0.05 was considered statistically significant. Funding: No external funding was obtained. Conflict of Interest: The authors declare no conflicts of interest.

Table 1: Characteristics of Participants Vaginal Delivery (n=100) Caesarean Section (n=100) n % n % Age (Mean, SD) 28.3 4.3 26.3 3.4 Gravida 1 29 29 26 26 2 18 18 28 28 3 26 26 24 24 4 27 27 22 22 Gestational Age at Delivery 37 12 12 23 23 38 19 19 15 15 39 24 24 16 16 40 25 25 23 23 41 20 20 23 23 Consistency of Meconium Thin Meconium 65 65 78 78 Thick Meconium 35 35 22 22 A total of 200 neonates were included, with 100 delivered vaginally and 100 via caesarean section. The mean maternal age in the vaginal delivery group was 28.3 ± 4.3 years, while in the caesarean section group it was 26.3 ± 3.4 years. In the vaginal group, 29% were primigravida, 18% were gravida 2, 26% were gravida 3, and 27% were gravida 4. In the caesarean group, 26% were primigravida, 28% were gravida 2, 24% were gravida 3, and 22% were gravida 4. Regarding gestational age at delivery, in the vaginal group, 12% delivered at 37 weeks, 19% at 38 weeks, 24% at 39 weeks, 25% at 40 weeks, and 20% at 41 weeks. In the caesarean group, 23% delivered at 37 weeks, 15% at 38 weeks, 16% at 39 weeks, 23% at 40 weeks, and 23% at 41 weeks. Thin meconium was observed in 65% of vaginal deliveries and 78% of caesarean deliveries. Thick meconium was noted in 35% of vaginal deliveries and 22% of caesarean deliveries (Table 1). Table 2: Association of Mode of Delivery and Neonatal Outcome Vaginal Delivery (n=100) Caesarean Section (n=100) n % n % APGAR Score at 1 Minute 2 31 31 21 21 Pearson chi2(3) = 9.4202 P-value = 0.024 3 37 37 26 26 4 18 18 26 26 5 14 14 27 27 Modified Downe's Score Category Mild 15 15 24 24 Pearson chi2(2) = 7.1835 P-value = 0.028 Moderate 58 58 63 63 Severe 27 27 13 13 NICU Admission No 46 46 65 65 Pearson chi2(1) = 7.3084 P-value = 0.007 Yes 54 54 35 35 Meconium Aspiration Syndrome No 85 85 95 95.0 Pearson chi2(1) = 5.55; P-value = 0.018 Yes 15 15 5 5.0 Perinatal Asphyxia No 72 72.0 86 86.0 Pearson chi2(1) = 5.9072 P-value = 0.015 Yes 28 28.0 14 14.0 Table 2 shows the association of Mode of Delivery and various Neonatal Outcome. A statistically significant difference was observed in neonatal outcomes based on the mode of delivery. • APGAR Score at 1 Minute: In the vaginal delivery group, 31% of neonates had an APGAR score of 2, 37% scored 3, 18% scored 4, and 14% scored 5. In the caesarean section group, 21% scored 2, 26% scored 3, 26% scored 4, and 27% scored 5 (p-value = 0.024). • Modified Downe's Score (Respiratory Distress Severity): In the vaginal group, 15% had mild distress, 58% moderate, and 27% severe. In the caesarean group, 24% had mild, 63% moderate, and 13% severe distress (p-value = 0.028). • NICU Admission: 54% of neonates delivered vaginally required NICU admission, compared to 35% in the caesarean group (p-value = 0.007). • Meconium Aspiration Syndrome (MAS): MAS was diagnosed in 15% of vaginal deliveries versus 5% of caesarean deliveries. The difference was statistically significant (p-value = 0.018). • Perinatal Asphyxia: 28% of neonates in the vaginal group developed perinatal asphyxia, compared to 14% in the caesarean group. This was also significant (p-value = 0.015). Table 3: Neonatal Mortality Vaginal Delivery (n=100) Caesarean Section (n=100) Neonatal Mortality n % n % No 97 97.0 99 99.0 Yes 3 3.0 1 1.0 Pearson chi2(1) = 1.0204 P-value = 0.312 Neonatal mortality was observed to be slightly higher in the vaginal delivery group compared to the caesarean section group. Out of 100 neonates delivered vaginally, 3 (3%) died, whereas only 1 (1%) neonatal death occurred among those delivered by caesarean section. However, this difference was not statistically significant (p = 0.312), indicating that the mode of delivery did not have a meaningful impact on neonatal mortality in this study.

In this study, thin meconium was observed more in both groups of delivery. In the vaginal delivery group, 65% of the patients exhibited thin meconium and 35% exhibited thick meconium. In the caesarean section group, 78% exhibited thin meconium and merely 22% exhibited thick meconium. These findings are similar to those of Parveen et al. (2023) where thin meconium was found in 69.6% and thick meconium in 30.4% of the newborns. They also found more complications in the thick meconium group[10]. Dani et al. (2023) observed that grade 3 thick meconium was more likely to have neonatal complications compared to grade 1. Thick meconium in their observation had an odds ratio of 33.79 (p<0.001) for adverse outcomes[11]. Patra et al. (2020) observed that 55% of their cases were thick meconium, and most were early in labour, and among this group, there was a very high risk of respiratory distress and MAS[12]. The findings of the present study support those of Nath P, who also observed a strong link between meconium-stained amniotic fluid and adverse neonatal outcomes.[13] In Nath’s study, out of 240 cases with MSAF, 103 newborns were admitted to the NICU, which accounts for 42.9%.[13] This is consistent with the current study, where 54% of vaginally delivered and 35% of caesarean-delivered babies required NICU admission, highlighting a significant burden of morbidity. Both studies point to a higher likelihood of NICU admission in MSAF cases, especially in vaginal deliveries. In this study, caесarean-delivered babies had higher APGAR scores at 1 minute than vaginally delivered babies. In the vaginally delivered group, 31% of the babies had a score of 2, and 37% had a score of 3. Only 14% had a score of 5. The caесarean group had fewer babies with a score of 2 (21%) and more with scores of 4 and 5 (26% and 27% respectively). The two groups were significantly different (p=0.024). A similar trend was documented by Medhi et al. (2023), where 23.47% of MAS babies had APGAR less than 4 at 1 minute, and the majority needed urgent NICU care.[14] Parveen et al. (2023) observed that thick meconium babies had 1-minute APGAR low and required ventilatory support. In their study, thick MSL cases had highest perinatal depression[10]. Dani et al. (2023) also reflected that grade 3 meconium babies had increased risk of low APGAR with odds ratio of 33.79 and p-value <0.001[15]. Patra et al. (2020) reported that vaginally delivered newborns with early thick meconium had lower APGAR scores than caesarean-delivered newborns[12]. In the study, 100% of the vaginally delivered MAS cases presented with ≤5 APGAR scores. Ranjbar et al. (2023) reported that APGAR scores at 1 and 5 minutes did not significantly differ according to the mode of delivery, but there was higher initial resuscitation in the vaginal group[16]. In the present study, respiratory distress was higher in the vaginally delivered group compared to the caesarean-delivered group. In vaginally delivered infants, 27% experienced severe Modified Downe's score, while only 13% of the caesarean group experienced severe distress. Mild distress was higher in the caesarean group (24%) compared to the vaginal group (15%). The groups were statistically different (p=0.028). Parveen et al. (2023) had previously reported that thick meconium infants mostly experienced moderate to severe respiratory distress and often needed invasive ventilation.[10] In this study, the morbidity burden was higher in the thick meconium group. Dani et al. (2023) also reported that grade 3 meconium was highly associated with adverse respiratory outcomes like MAS, ARDS, and PPHN, with strong statistical significance (p<0.001).[15] Patra et al. (2020) reported that 18% of the babies born through vaginal delivery with early thick meconium developed respiratory distress, while only 9% of the babies born through caesarean developed distress.[12] They reported that mode of delivery decreases the severity of respiratory complications. Medhi et al. (2023) reported that the majority of the babies with MAS developed moderate to severe distress, and some of them required NICU admission and respiratory treatment.[14] Ranjbar et al. (2023) also reported that while the route of delivery was not statistically associated with overall outcomes, the requirement for resuscitation and early intervention was more frequent in the vaginal group.[16] In our research currently, NICU admission was also greater among infants delivered vaginally. Within the vaginal delivery group, 54% of babies required NICU admission, while only 35% of infants in the group delivered by caesarean section required NICU admission. The difference was statistically significant (p=0.007), which implies that babies delivered vaginally had higher chances of having complications. Parveen et al. (2023) noted that thick meconium was associated with higher NICU admissions, especially in infants with MAS or respiratory distress.[10] Their study revealed a 55.2% rate of morbidity and noted that thick meconium was the major contributing factor. NICU admissions were higher with the severity of meconium staining as noted by Dani et al. (2023).[15] Grade 3 meconium was associated with a significantly higher risk of adverse outcomes (p<0.001). Patra et al. (2020) reported that infants with thick meconium in early pregnancy had poor perinatal outcomes if there was vaginal delivery.[12] They found that their study indicated that urgent caesarean delivery in the event of thick meconium reduced NICU admission. Medhi et al. (2023) reported that 64.34% of MAS were admitted to NICU and most of them were associated with vaginal delivery.[14] Ranjbar et al. (2023) found no statistical difference in NICU admissions in caesarean and vaginal groups, but initial resuscitation was seen more frequently in vaginal delivery.[16] In the current study, there is a clear advantage of caesarean section to avoid NICU admissions. In the current research, perinatal asphyxia occurred more frequently in the vaginally born group. 28% of the vaginally born babies had evidence of asphyxia, whereas only 14% of the caesarean-born babies had the condition. The difference was statistically significant (p=0.015), suggesting increased risk of asphyxia in vaginally born babies in meconium-stained babies. Parveen et al. (2023) reported perinatal depression to be the most common complication in infants with thick meconium.[10] A higher incidence of asphyxia was also noted in such infants, necessitating NICU care and respiratory management. Dani et al. (2023) indicated that grade 3 meconium was independently related to a number of complications, such as hypoxic-ischaemic encephalopathy, which is highly related to perinatal asphyxia (p<0.001).[15] Medhi et al. (2023) observed that 15.65% of MAS was also associated with birth asphyxia, confirming the correlation between meconium aspiration and low birth oxygen.[14] Ranjbar et al. (2023) reported no variation in the frequency of asphyxia between modes of delivery but reported a greater requirement for urgent resuscitation in the vaginal group.[16] In the present research, neonatal mortality was slightly higher in the vaginally delivered group. Out of the vaginally delivered group, 3% expired in the early neonatal period, while 1% expired in the caesarean section group. It was not significantly different (p=0.312). Parveen et al. (2023) encountered 3.4% mortality in the neonatal period with the majority being in the infants with thick meconium.[10] They recommended a reduction in risk through early intervention and detection. Medhi et al. (2023) encountered 2.6% mortality in MAS cases with most deaths being amongst the term-born vaginally infants.[14] Patra et al. (2020) did not observe any neonatal mortality in thick meconium cases in early stages treated with emergency caesarean section. This suggests that early surgery in severe cases can reduce mortality.[12] However, the risk of severe disease and intensive care was higher in grade 3 meconium. Ranjbar et al. (2023) did not observe a difference in neonatal death between vaginal delivery and caesarean delivery.[16] The findings concur with the present study, as mortality was low and not affected significantly by mode of delivery.

This study shows that the mode of delivery in cases of meconium-stained amniotic fluid significantly affects immediate neonatal outcomes. Neonates delivered by caesarean section had better APGAR scores, lower respiratory distress, fewer NICU admissions, and lower rates of meconium aspiration syndrome and perinatal asphyxia compared to those delivered vaginally. Although neonatal mortality was slightly higher in the vaginal group, the difference was not statistically significant. The presence of thick meconium was more often associated with adverse outcomes. Caesarean section may be a safer option in selected cases of MSAF, especially when thick meconium is present or signs of fetal compromise are observed.

1. Mitchell S, Chandraharan E. Meconium-stained amniotic fluid. Obstet Gynaecol Reprod Med [Internet]. 2018;28(4):120–4. 2. Gallo DM, Romero R, Bosco M, Gotsch F, Jaiman S, Jung E, et al. Meconium-stained amniotic fluid. Am J Obstet Gynecol. 2023;228(5):S1158–78. 3. Ross MG. Meconium Aspiration Syndrome — More Than Intrapartum Meconium. N Engl J Med [Internet]. 2005;353(9):946–8. 4. Ahanya SN, Lakshmanan J, Morgan BLG, Ross MG. Meconium passage in utero: Mechanisms, consequences, and management. Obstet Gynecol Surv [Internet]. 2005;60(1):45–56. 5. Van Ierland Y, De Boer M, De Beaufort AJ. Meconium-stained amniotic fluid: Discharge vigorous newborns. Arch Dis Child Fetal Neonatal Ed [Internet]. 2010;95(1). 6. Cunningham FG, Leveno KJ, Dashe JS, Hoffman BL, Spong CY, Casey BM. Intrapartum Assessment. In: Williams Obstetrics, 26e. New York, NY: McGraw Hill; 2022. 7. Cunningham FG, Leveno KJ, Dashe JS, Hoffman BL, Spong CY, Casey BM. Normal Labor. In: Williams Obstetrics, 26e. New York, NY: McGraw Hill; 2022. 8. Tsakiridis I, Mamopoulos A, Athanasiadis A, Dagklis T. Induction of Labor: An Overview of Guidelines. Obstet Gynecol Surv [Internet]. 2020;75(1):61–72. 9. Paudel P, Sunny AK, Poudel PG, Gurung R, Gurung A, Bastola R, et al. Meconium aspiration syndrome: incidence, associated risk factors and outcome-evidence from a multicentric study in low-resource settings in Nepal. J Paediatr Child Health [Internet]. 2020;56(4):630–5. 10. Parveen A, S. U, K. P, N. KR. Clinical outcome of babies born through meconium stained liqour. Int J Contemp Pediatr [Internet]. 2023;10(11):1699–704. 11. Dani C, Ciarcià M, Barone V, Di Tommaso M, Mecacci F, Pasquini L, et al. Neonatal Outcomes of Term Infants Born with Meconium-Stained Amniotic Fluid. Children. 2023;10. 12. Patra S, S. SS, Puri M, Nangia S, Trivedi SS. Meconium stained liquor in labour and mode of delivery: a time for reappraisal. Int J Reprod Contraception, Obstet Gynecol [Internet]. 2020;9(10):4016. 13. Nath P. Meconium stained amniotic fluid: A correlation with mode of delivery and perinatal outcome. New Indian J OBGYN [Internet]. 2018;4(2):158–60. 14. Medhi G, Hussain F, Das I, Das H. A study on clinical profile of meconium aspiration syndrome in relation to gestational age and birth weight and their immediate outcome. New Indian J OBGYN [Internet]. 2023;9(2):274–8. 15. Dani C, Ciarcià M, Barone V, Di Tommaso M, Mecacci F, Pasquini L, et al. Neonatal Outcomes of Term Infants Born with Meconium-Stained Amniotic Fluid. Children [Internet]. 2023;10(5):1–9. 16. Ranjbar A, Ghamsari SR, Taeidi E, Mehrnoush V, Darsareh F. Does cesarean section prevent adverse neonatal outcomes associated with meconium amniotic fluid? Gynecol Obstet Clin Med. 2023;3(4):241–4.