Risk Factors for Grade III Meconium-Stained Amniotic Fluid in Term Singleton Pregnancies: A Retrospective Comparative Study
DOI:
https://doi.org/10.70088/04j8x313Keywords:
Meconium-stained amniotic fluid, grade III, term pregnancy, risk factors, Group B StreptococcusAbstract
Background: Grade III meconium-stained amniotic fluid (MSAF) is an important intrapartum finding associated with increased perinatal risk. However, risk factors for severe meconium contamination in term singleton pregnancies remain incompletely defined. Objective: This study aimed to identify maternal, obstetric, intrapartum, and infection-related factors associated with grade III MSAF in term singleton pregnancies. Methods: This retrospective comparative study included 200 women with term singleton pregnancies who delivered at Lingnan Hospital, The Third Affiliated Hospital of Sun Yat-sen University, between January 2023 and December 2024. Women were divided into a grade III MSAF group (n=100) and a clear amniotic fluid control group (n=100). Maternal characteristics, obstetric variables, intrapartum factors, laboratory findings, and ultrasound parameters were compared between groups. Variables with P<0.05 in univariate analysis were entered into a multivariable logistic regression model to identify independent risk factors for grade III MSAF. Results: Compared with controls, women with grade III MSAF had a higher proportion of advanced maternal age, higher gestational age at delivery, higher proportion of gravidity ≥2, longer first stage of labor, higher incidence of intrapartum fever, higher frequency of elevated pre-delivery white blood cell count, and higher rate of maternal Group B Streptococcus colonization. Multivariable logistic regression analysis showed that longer duration of the first stage of labor (OR=1.002, 95% CI: 1.000--1.003, P=0.034), higher gestational age at delivery (OR=1.532, 95% CI: 1.002--2.344, P=0.049), gravidity ≥2 (OR=3.377, 95% CI: 1.410--8.085, P=0.006), elevated pre-delivery white blood cell count (OR=4.518, 95% CI: 1.109--18.408, P=0.035), and maternal GBS colonization (OR=17.896, 95% CI: 7.161--44.729, P<0.001) were independently associated with grade III MSAF. Conclusion: Higher gestational age at delivery, gravidity ≥2, prolonged first stage of labor, elevated pre-delivery white blood cell count, and maternal GBS colonization were independent risk factors for grade III MSAF in term singleton pregnancies. These findings suggest that both labor-related and infection-related factors should be considered in intrapartum risk assessment for severe meconium contamination.References
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