Severe adverse maternal outcomes associated with chorioamnionitis

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

Risk of disseminated intravascular coagulation in postpartum hemorrhage associated with intrauterine infection

OBJECTIVE

To evaluate the risk of disseminated intravascular coagulation (DIC) in postpartum hemorrhage (PPH) associated with intrauterine infection.

MATERIAL AND METHODS

A retrospective cohort study of pregnancies complicated by PPH performed at a tertiary academic center in France from 2017 through 2021. Patients giving birth after 22 weeks of gestation with PPH were eligible. Patients with a PPH associated with an intrauterine infection were compared to patients with a PPH without intrauterine infection. Intrauterine infection was defined by a composite criterion available at delivery. DIC was defined by a specific pregnancy DIC score. The association between DIC and intrauterine infection was assessed by logistic regression. The causal effect of intrauterine infection on DIC was estimated by mediation analysis.

RESULTS

Of 2,093 patients with PPH, 49 exposed to a clinical intrauterine infection were compared to 49 unexposed patients. The rate of DIC was higher in patients with than without infection (22 (45.8%) vs. 7 (14.6%), P = .001), and coagulation anomalies occurred sooner in patients with than without infection (7, 2-11 h vs. 14, 9-19 h, P < .001). In the multivariate analysis, intrauterine infection was the only factor independently associated with DIC (adjusted odds ratio 5.01, 95% CI 1.83-13.73). Mediation analysis showed that 14% (95% CI, 0-50%) of this association between intrauterine infection and DIC was mediated by severe PPH, and 86% resulted from the direct effect of intrauterine infection on DIC.

CONCLUSION

In PPH, intrauterine infection had a major direct effect on the occurrence, timing, and severity of DIC.

Maternal plasma cytokines and the subsequent risk of uterine atony and postpartum hemorrhage

OBJECTIVES

To determine whether the maternal plasma concentrations of cytokines are higher in pregnant women with postpartum hemorrhage (PPH) compared to pregnant women without PPH.

METHODS

A retrospective case-control study included 36 women with PPH and 72 matched controls. Cases and controls were matched for gestational age at delivery, labor status, delivery route, parity, and year of sample collection. Maternal plasma samples were collected up to 3 days prior to delivery. Comparison of the plasma concentrations of 29 cytokines was performed by using linear mixed-effects models and included adjustment for covariates and multiple testing. A false discovery rate adjusted p-value <0.1 was used to infer significance. Random forest models with evaluation by leave-one-out and 9-fold cross-validation were used to assess the combined value of the proteins in predicting PPH.

RESULTS

Concentrations of interleukin (IL)-16, IL-6, IL-12/IL-23p40, monocyte chemotactic protein 1 (MCP-1), and IL-1β were significantly higher in PPH than in the control group. This difference remained significant after adjustment for maternal age, clinical chorioamnionitis, and preeclampsia. Multi-protein random forest proteomics models had moderate cross-validated accuracy for prediction of PPH [area under the ROC curve, 0.69 (0.58-0.81) by leave-one-out cross validation and 0.73 (0.65-0.81) by 9-fold cross-validation], and the inclusion of clinical and demographic information did not increase the prediction performance.

CONCLUSIONS

Pregnant women with severe PPH had higher median maternal plasma concentrations of IL-16, IL-6, IL-12/IL-23p40, MCP-1, and IL-1β than patients without PPH. These cytokines could serve as biomarkers or their pathways may be therapeutic targets.

Monofilament suture versus braided suture thread to improve pregnancy outcomes after vaginal cervical cerclage (C-STICH): a pragmatic randomised, controlled, phase 3, superiority trial

BACKGROUND

Miscarriage in the second trimester and preterm birth are significant global problems. Vaginal cervical cerclage is performed to prevent pregnancy loss and preterm birth. We aimed to determine the effectiveness of a monofilament suture thread compared with braided suture thread on pregnancy loss rates in women undergoing a cervical cerclage.

METHODS

C-STICH was a pragmatic, randomised, controlled, superiority trial done at 75 obstetric units in the UK. Women with a singleton pregnancy who received a vaginal cervical cerclage due to a history of pregnancy loss or premature birth, or if indicated by ultrasound, were centrally randomised (1:1) using minimisation to receive a monofilament suture or braided suture thread for their cervical cerclage. Women and outcome assessors were masked to allocation as far as possible. The primary outcome was pregnancy loss, defined as miscarriage, stillbirth, or neonatal death in the first week of life, analysed in the intention-to-treat population (ie, all women who were randomly assigned). Safety was also assessed in the intention-to-treat population. The trial was registered with ISRCTN, ISRCTN15373349.

FINDINGS

Between Aug 21, 2015, and Jan 28, 2021, 2049 women were randomly assigned to receive a monofilament suture (n=1025) or braided suture (n=1024). The primary outcome was ascertained in 1003 women in the monofilament suture group and 993 women in the braided suture group. Pregnancy loss occurred in 80 (8·0%) of 1003 women in the monofilament suture group and 75 (7·6%) of 993 women in the braided suture group (adjusted risk ratio 1·05 [95% CI 0·79 to 1·40]; adjusted risk difference 0·002 [95% CI -0·02 to 0·03]).

INTERPRETATION

Monofilament suture did not reduce rate of pregnancy loss when compared with a braided suture. Clinicians should use the results of this trial to facilitate discussions around the choice of suture thread to optimise outcomes.

FUNDING

National Institute of Health Research Health Technology Assessment Programme.

A retrospective study of risk factors for early-onset neonatal sepsis with intrapartum maternal fever

Background

Intrapartum fever is a well-known risk factor for adverse perinatal outcomes. In this study, we evaluated the clinical features for intrapartum maternal fever and investigated the risk factors for neonatal early-onset sepsis (EOS) with intrapartum maternal fever.

Methods

This retrospective cohort study involved a total of 568 neonates born to mothers with intrapartum maternal fever (temperature peak ≥38 degree Celsius) in Hangzhou Women's Hospital from January 1st to December 31st, 2019. Neonates were assigned to the EOS and non-sepsis groups based on the diagnostic criteria for early-onset neonatal sepsis,. Demographic data, clinical information and laboratory test results were evaluated to assess the risk factors for EOS.

Results

A total of 568 neonates were included in this study, 84 of whom were diagnosed with EOS. The EOS group was significantly different from the non-sepsis group in 11 items including the both white blood cell (WBC) count and C-reactive protein (CRP) level of the mother before delivery (p < 0.05). A logistic regression analysis revealed that a high maternal WBC count before delivery (OR = 3.261, p = 0.019) and a maternal histological chorioamnionitis (HCA) diagnosis (OR = 5.608, p = 0.002) were independent risk factors for EOS. The optimal cut-off value for WBC (before delivery) was 16.75 × 10*9/L for EOS, according to receiver operating characteristic analysis (area under curve was 0.821).

Conclusions

Elevated prenatal maternal WBC counts and maternal HCA diagnosis are both independently associated with EOS. Prenatal maternal WBC counts can be used as a sensitive indicator to predict EOS early.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.