Low-grade intrapartum fever and operative vaginal delivery: A retrospective cohort study.
To evaluate the association between low-grade intrapartum fever (37.5-37.9°C) and obstetric and neonatal outcomes, and to compare its clinical significance with that of overt intrapartum fever (≥38.0°C).
This retrospective cohort study included nulliparous women with singleton pregnancies who delivered over a 7-year period at a single tertiary academic medical center. Participants were categorized according to maximal intrapartum maternal temperature into three groups: low-grade intrapartum fever (37.5-37.9°C), overt intrapartum fever (≥38.0°C), and afebrile controls. The primary analysis focused on outcomes associated with low-grade fever compared with afebrile women, while the intrapartum fever group was included as a reference to contextualize the magnitude of risk. The primary outcomes were operative vaginal delivery (OVD) and intrapartum cesarean delivery (CD), analyzed separately. Secondary outcomes included selected neonatal outcomes, including a 5-minute Apgar score < 7. Multivariable logistic regression was performed to adjust for potential confounders.
A total of 15,093 women met inclusion criteria, including 1,294 (8.6%) with low-grade intrapartum fever, 934 (6.2%) with overt intrapartum fever (≥38.0°C), and 12,865 (85.2%) afebrile controls. Compared with afebrile controls, women with low-grade fever had higher rates of OVD (27.0% vs. 17.0%, p < 0.001), although rates remained lower than those observed in the overt fever group (31.0%, p < 0.001). Cesarean delivery rates were increased only among women with overt intrapartum fever and were comparable between the low-grade fever and afebrile groups. Low-grade fever was also associated with a higher rate of 5-minute Apgar score < 7 compared with controls (0.9% vs. 0.4%, p = 0.034). After adjustment for maternal age, diabetes mellitus, hypertensive disorders, gestational age at delivery, labor induction, epidural analgesia, and neonatal birthweight, low-grade intrapartum fever remained independently associated with increased risk of OVD (adjusted OR 1.54, 95% CI 1.35-1.76) and 5-minute Apgar score < 7 (adjusted OR 2.50, 95% CI 1.28-4.89).
Low-grade intrapartum temperature elevation was independently associated with increased operative vaginal delivery and low 5-minute Apgar score. These findings suggest that subfebrile temperature elevations may identify a more complicated intrapartum course, although the temporal relationship between temperature elevation and labor progression or delivery mode, and therefore causality, cannot be established.
This retrospective cohort study included nulliparous women with singleton pregnancies who delivered over a 7-year period at a single tertiary academic medical center. Participants were categorized according to maximal intrapartum maternal temperature into three groups: low-grade intrapartum fever (37.5-37.9°C), overt intrapartum fever (≥38.0°C), and afebrile controls. The primary analysis focused on outcomes associated with low-grade fever compared with afebrile women, while the intrapartum fever group was included as a reference to contextualize the magnitude of risk. The primary outcomes were operative vaginal delivery (OVD) and intrapartum cesarean delivery (CD), analyzed separately. Secondary outcomes included selected neonatal outcomes, including a 5-minute Apgar score < 7. Multivariable logistic regression was performed to adjust for potential confounders.
A total of 15,093 women met inclusion criteria, including 1,294 (8.6%) with low-grade intrapartum fever, 934 (6.2%) with overt intrapartum fever (≥38.0°C), and 12,865 (85.2%) afebrile controls. Compared with afebrile controls, women with low-grade fever had higher rates of OVD (27.0% vs. 17.0%, p < 0.001), although rates remained lower than those observed in the overt fever group (31.0%, p < 0.001). Cesarean delivery rates were increased only among women with overt intrapartum fever and were comparable between the low-grade fever and afebrile groups. Low-grade fever was also associated with a higher rate of 5-minute Apgar score < 7 compared with controls (0.9% vs. 0.4%, p = 0.034). After adjustment for maternal age, diabetes mellitus, hypertensive disorders, gestational age at delivery, labor induction, epidural analgesia, and neonatal birthweight, low-grade intrapartum fever remained independently associated with increased risk of OVD (adjusted OR 1.54, 95% CI 1.35-1.76) and 5-minute Apgar score < 7 (adjusted OR 2.50, 95% CI 1.28-4.89).
Low-grade intrapartum temperature elevation was independently associated with increased operative vaginal delivery and low 5-minute Apgar score. These findings suggest that subfebrile temperature elevations may identify a more complicated intrapartum course, although the temporal relationship between temperature elevation and labor progression or delivery mode, and therefore causality, cannot be established.
Authors
Cohen Cohen, Greenfield Greenfield, Markovich Markovich, Kovo Kovo, Biron-Shental Biron-Shental, Schreiber Schreiber
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