Meconium, the gastrointestinal excreta of the fetus was named by Aristotle. The word meconium is derived from Greek word “Meconium Arion” which means opium like or poppy like substances causing sleeping state of the fetus in mother’s womb. Meconium is the first intestinal secretion from the fetus. It starts as early as 10 weeks of gestation and incidence of intrauterine passage of meconium increases with the gestational age. Meconium staining of AF is a commonly observed phenomenon in day-to- day practice of obstetrics and its significance as a sign of fetal distress is controversial. The passage of meconium in utero has been described by various authors by different mechanisms. Few theories have been suggested for fetal passage of meconium [1-3].

The pathological explanation proposes that fetuses pass meconium in response to fetal hypoxia. In utero passage of meconium represents normal gastrointestinal tract maturation, which is under neural control. Commonly, meconium passage occurs following relaxation of anal sphincter and increased peristalsis due to vagal stimulation. By the end of the sixteenth week of gestation, the gastrointestinal functions of the fetus are sufficiently developed to absorb much of water from it, propel the unabsorbed matter as far as the lower colon. During intrauterine life fetus [4, 5].  Normally does not pass meconium as the peristaltic movements of fetal intestine remain quiescent. But if fetal hypoxia occurs, intestinal peristalsis increases sufficiently that causes the unabsorbed matter to be excreted per anum. This fetal excreta is called the meconium. But in quite a good number of cases, no definite cause could be found; probably these were the cases where physiological expulsion of meconium took place. The major goal of obstetric care is to prevent maternal and fetal morbidity and mortality. To reduce fetal morbidity and mortality, early identification of markers of fetal distress is important. The classical signs or markers of fetal hypoxia are loss of fetal movements or decreased fetal movements, variations in fetal heart rate pattern, presence of meconium in AF, presence of fetal moulding and decrease in fetal scalp blood pH [6, 7].

Meconium acts as a good culture medium, causes inflammatory reaction if aspirated by the fetus and sometimes causes obstruction in the lungs. With the decline of maternal mortality and morbidity over the past few decades, modern obstetricians are much more concerned about the welfare of the fetus during pregnancy, labour and after birth. Presence of meconium in the AF or detection of fetal heart rate abnormality is said to indicate fetal distress which may result in still birth or in the birth of an asphyxiated baby with the consequences of that being brain damage, neurological problem and other manifestations [8, 9].

The present study “Maternal risk factors and the perinatal outcome in meconium stained amniotic fluid” will help to correlate meconium stained AF with the maternal risk factors and also the fetal outcome. Since all fetuses with meconium passage in labour do not have associated maternal risk factors and do not have adverse outcome, it is important to identify those who are destined to develop fetal distress promptly and intervene accordingly to prevent meconium aspiration syndrome and sequel [10-12].

The incidence of meconium stained amniotic fluid greatly varies with maternal risk factors. This study is an effort to ascertain whether meconium staining of AF has any correlation with high risk factors predisposing to fetal distress in labour and to assess exactly the fetal condition and outcome in all cases of MSAF with the help of data obtained in the present series. The aim and objective so if this study was to study the various maternal risk factors responsible for meconium stained amniotic fluid. To study the mode of delivery in a labour complicated by meconium stained amniotic fluid. To study the sequel of events on neonates in meconium stained amniotic fluid. To compare the perinatal outcome in thick and thin meconium stained amniotic fluid [13-15].

This study was conducted in the department of Obstetrics and Gynaecology at Government Medical College, Mahbubnagar, Telangana, India for a period of one year from May 2024 to April 2025. It is an observational study, includes 100 cases admitted in hospital after 37 weeks of gestation for delivery who exhibit meconium stained liquor after spontaneous or artificial rupture of membranes. The data was collected using a preset proforma who met the criteria for the study. The data was collected from above mentioned source using the following inclusion and exclusion criteria.

Inclusion Criteria:

• Term labour (>37 completed weeks)
• Cephalic presentation
• Live singleton pregnancy

Exclusion Criteria:

• Antepartum hemorrhage
• Multiple pregnancy
• Malpresentations
• Pregnancy with congenital malformations.
• Intrauterine death

Mothers in labour were studied when meconium was found at the time of rupture of membrane or when clear AF turned meconium stained during the course of labour. A total number of 100 cases were studied. Associated maternal risk factors and the babies delivered vaginally/vacuum or forceps delivery/CS, according to the obstetrical findings were followed up and taken into consideration in analyzing the perinatal outcome.

This study was conducted in the department of Obstetrics and Gynaecology at Government Medical College, Mahbubnagar, and Telangana, India for a period of one year from May 2024 to April 2025, taking 100 delivering women at term with meconium stained amniotic fluid. Antenatal records of all the study subjects were scrutinized to search the antenatal risk factors and the labour monitored for intrapartum risk factors and delivered babies followed postnatally for perinatal outcome. Cases were divided into two groups based on meconium consistency- thin and thick. The data was recorded for each group and statistical analysis done.

Table 1: Age Group Distribution in MSAF As Noted By Other Author

Sandhu et al.  noted 80% of cases with MSAF belonged to the age group of 21-30 years. In our study 86% of cases with MSAF belong to the same age group.

Table 2: Comparision of incidence of MSAF with parity of mothers

Higher incidence of MSAF was seen in Primigravida that is 59%. This study was correlating with the study done by Gokhroo et al.

Table 3: Comparision of gestational age at birth as noted by other authors

James et al. mentions incidence of MSAF increases with gestational age and reaches approximately 30% at 40 weeks and 50% at 42 weeks. Hiremath et al. did a similar study in which the gestational age from 40 – 42 weeks was up to 36% and they had large number of cases (40%) > 42 weeks. In present study large group of cases belong to gestational age 40 - 42 weeks.

Table 4: Comparision of antepartum and intrapartum risk factors as noted by other authors

In present study following were the associated antepartum and intrapartum risk factors - prolonged labour, hypertensive disorder, oligohydramnios, IUGR, anaemia. Cases with postdatism had increased incidence of MSAF. More than one risk factor was seen in 8 cases. Out of the 6 cases with IUGR fetus, one had abnormal Doppler changes. In the study conducted by Hiremath et al., 33% of MSAF cases had anaemia and 42% of MSAF cases had HDP. In contrast, present study had 21% of MSAF cases with anaemia and only 4% of MSAF cases with HDP.

Table 5: Showing CTG Study In MSAF by Other Author

In a study by Rosario and Seshadri, 4% cases in thin MSAF group had abnormal CTG while 54% cases in thick MSAF group. Early detection of fetal distress through non-reactive CTG helps in reducing the neonatal morbidity and mortality. Out of total 26 cases with thin MSAF and abnormal CTG changes, only one(3.84%) case needed LSCS while in thick MSG, 16 cases had abnormal CTG changes and 5(31.25%) had to undergo LSCS.

Table 6: Mode of delivery in MSAF recorded by other author

In comparison to thin group, incidence of cesarean section was almost four times in thick group (7.46% in thin group and 30.30% in thick group). There was increased incidence of instrumental delivery in meconium stained group cases in our study (30%). Out of 67 cases with thin MSAF, 19(28.36%) had instrumental deliveries while in thick MSG, 11(33.33% of 33 cases) had instrumental delivery. In thin MSG, 2 cases had forceps delivery and 17 had vacuum delivery while in thick MSG, 2 had forceps delivery and 9 had vacuum delivery. Out of total MSAF cases, 15% delivered by cesarean section, 5 with thin MSAF and 10 with thick MSAF.

Table 7:  Mean Birth Weight Observed By Different Authors

Fujikura & Klionsky observed that the incidence of meconium staining was significantly more with increased birth weight more than 3 kg. In present study mean birth weight was 3.02 Kg which coincides with other studies.

MSAF and APGAR score:

Majority of the authors observed that incidence of birth asphyxia among the babies born with MSAF was more compared to the control cases with clear AF. Workers like Walker, Desmond et al. concluded that this high rate of depressed babies in stained group was the result of intrauterine hypoxia.

Table 8: Comparision of Apgar score At 1 Minute in MSAF with Other Author

At one minute APGAR scores were good in thin MSAF compared to thick MSAF. In our study, majority (80% of newborns) had at one minute APGAR score between 4-6 in contrast to the study done by Miller et al.

Table 9: Comparision of Apgar score At 5 Minutes in MSF

There was improvement in APGAR score at 5 minutes. Low APGAR score at 5 minutes indicated poor neonatal outcome, were seen more commonly in thick meconium stained cases(18.18% against 10.45%) but statistical significance was not found(P value= 0.280). The results were comparable with the study done by Miller et al.

Table 10: Correlation of 5 Minutes Apgar score Between 4 – 6 with CTG, Mode of delivery & nicu admission in thin and thick msaf in present study

In present study, 80% babies had 1 min APGAR score between 4-6 which improved in most of them at 5 minutes. But 10% (7 cases) of babies in thin MSG and 18 %( 6 cases) of babies in thick MSG had persistently low APGAR scores at 5 min, between 4-6. 10 (5 from thin MSG and 5 from thick MSG) of these babies with 5 mins APGAR score between 4-6 had intrapartum abnormal CTG changes, 3(2 from thick MSG and 1 from thin MSG) had to undergo LSCS. These 13 cases required further active neonatal management and observed in NICU. Only one (belonging to thin MSG) baby showed significant improvement while 12(6 from thin MSG and 6 from thick MSG) cases required further NICU admission and care.

Table 11: Showing Different Incidence of Birth Asphyxia in MSAF As Reported By Different Workers

It is evident from the above list that Miller and Meis recorded nearly triple incidence of birth asphyxia in stained group compared to control group. In the present study incidence of birth asphyxia in MSG was 10%. Percentage of asphyxiated babies was different in different groups of MSAF. In present study it was 6% in thin group and 18.1% in thick group. It shows that birth asphyxia is more common in thick group compared to thin group (P=0.0278).

Meconium stained amniotic fluid (MSAF) continues to be a significant concern in obstetrics due to its potential association with fetal distress, increased rates of cesarean section, and neonatal complications. In the present study, we analyzed the maternal risk factors associated with MSAF and evaluated the perinatal outcomes, comparing the findings between thin and thick meconium groups [16-18].

Our study demonstrated that the incidence of MSAF was higher in primigravidae (59%), consistent with the findings of Gokhroo et al., who reported 54%. This may be attributed to a relatively longer and unconditioned labour in primigravidae, making the fetus more susceptible to stress. The majority (86%) of women were between 20–30 years, aligning with the typical reproductive age group most commonly presenting in labour wards, and matching the age distribution reported by Sandhu et al [19-21].

A significant finding in our study was the association between MSAF and gestational age, where 62% of the cases were between 40–42 weeks. This supports existing literature, such as James et al., who observed increased meconium passage in postdated pregnancies. This reinforces the theory that advancing gestational age increases bowel maturation and the likelihood of in utero meconium passage [22-24].

In terms of maternal risk factors, our findings highlight anaemia (21%), prolonged labour (10%), IUGR (6%), and oligohydramnios (6%) as notable contributors. Notably, hypertensive disorders were seen only in 4% of cases, a lower rate compared to Hiremath et al., who reported 42%. These discrepancies may be due to different population characteristics or antenatal care standards. The identification of such risk factors is critical in the prediction and prevention of adverse perinatal outcomes associated with MSAF [25, 26]. Cardiotocographic (CTG) abnormalities were more frequent in the thick meconium group (48.48%) compared to the thin group (38.80%), although the difference was not statistically significant (P=0.356). However, among those with abnormal CTG, cesarean section was more commonly required in the thick group. This supports the view that thick MSAF correlates more strongly with intrapartum fetal distress [27].

With regard to the mode of delivery, our study showed that instrumental deliveries and cesarean sections were significantly higher in thick MSAF cases (33.3% and 30.3% respectively) compared to thin MSAF (28.36% and 7.46%). This is in line with findings from Goud & Krishna and indicates the increased obstetric intervention required in the presence of thick meconium to prevent adverse neonatal outcomes [28]. Neonatal outcomes in our study clearly differed between the two groups. Apgar scores at 1 and 5 minutes were lower in the thick MSAF group, and NICU admissions were more frequent (24.24% in thick vs. 8.96% in thin). Birth asphyxia was observed in 10% of all MSAF cases, with 18.1% in the thick and 6% in the thin group. These findings are consistent with previous studies (Desmond et al., Miller et al.) which also demonstrated significantly higher perinatal morbidity in thick MSAF cases [29]. Interestingly, despite the presence of MSAF, 86% of newborns were healthy, and 61% of cases had no identifiable maternal risk factors, indicating that not all instances of MSAF are pathological. This underscores the importance of clinical context and careful monitoring, rather than aggressive intervention based solely on MSAF presence. The perinatal morbidity rate of 14% in our study is comparable to studies by Nayak & Dalal and Gokhroo et al. While meconium aspiration syndrome (MAS) was rare, it was more commonly associated with thick meconium and required intensive neonatal care including mechanical ventilation. One neonatal death occurred in a thin MSAF case with MAS and abnormal intrapartum CTG, reinforcing the need for vigilant monitoring even in seemingly lower-risk scenarios [30, 31].

Overall, the findings of this study support existing literature regarding the increased perinatal risks associated with thick meconium and the importance of identifying and managing underlying maternal risk factors. The data also highlight that while MSAF is a potential marker of fetal compromise, its presence alone—particularly when thin—does not always necessitate emergency intervention. Clinical decisions should be individualized, incorporating fetal heart rate patterns, consistency of meconium, and overall maternal and fetal condition [32, 33].

The incidence of meconium stained amniotic fluid greatly varies with maternal antenatal and intrapartum risk factors. Increased incidence was seen in cases with crossed dates. Hypertensive disorders of pregnancy and oligohydramnios compared to other factors, had a significant association with meconium stained liquor, P < 0.05. As per the mode of delivery concerned, increased incidence of cesarean section was significantly associated with the consistency of meconium. Meconium stained amniotic fluid is not significantly associated with abnormal fetal heart rate (P > 0.05), should be interpreted with caution while deciding any active intervention. Since all fetuses with meconium passage in labour do not have associated risk factor (61% in this study) and all do not have adverse outcome (86% were healthy babies), it is important to promptly identify those who are destined to develop foetal distress and intervene accordingly to prevent meconium aspiration syndrome and sequel.

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