Duration of labor and risk of cerebral white-matter damage in very preterm infants who are delivered with intrauterine infection

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.

Risk factors for the deterioration of periventricular-intraventricular hemorrhage in preterm infants

Preterm infants with periventricular–intraventricular hemorrhage (PV–IVH) have a high risk of neurological sequelae, with severity depending on the severity of the PV–IVH. Previous studies on the pathogenesis of PV–IVH have focused mainly on comparisons of perinatal risk factors between patients with and without PV–IVH. Notably, most cases of PV–IVH occur within the first 3 days after birth, and the condition may worsen within 1 week following the initial diagnosis. However, the risk factors that contribute to the deterioration of PV–IVH have not been investigated. In this cohort study, 514 PV–IVH infants with a gestational age (GA) < 32 weeks were enrolled. The dependent variable was initially diagnosed as mild PV–IVH (grade I or II) that subsequently progressed to severe PV–IVH (grade III or IV) within 1 week. A stepwise forward multivariate logistic regression model was adopted to select potential or related factors that affected the deterioration of PV–IVH in preterm infants. Overall, 42 of the 514 infants with PV–IVH (8.2%) showed deterioration within 1 week. The results showed that maternal lower genital tract infection (OR 3.73, 95% CI 1.75–7.95) was an independent risk factor for PV–IVH deterioration. Higher GA (OR 0.62, 95% CI 0.48–0.80) was a protective factor. Our results suggest that maternal lower genital tract infection and a lower GA may contribute to PV–IVH deterioration in preterm infants.

Planned Mode of Delivery of Preterm Twins and Neonatal and 2-Year Outcomes

OBJECTIVE

To assess neonatal and 2-year outcomes for preterm twins born after planned vaginal delivery compared with planned cesarean delivery.

METHODS

Women with preterm cephalic first twins delivered after preterm labor or preterm prelabor rupture of membranes from 24 0/7 to 34 6/7 weeks of gestation, with both fetuses alive at the beginning of labor, were identified from the national prospective population-based Etude Epidémiologique sur les Petits Ages Gestationnels 2 cohort study. Planned vaginal delivery was defined as vaginal delivery or cesarean delivery performed during labor. Planned cesarean delivery was considered if performed during labor for the indication of preterm twins or before labor whatever the indication. A propensity score analysis was used to compare planned vaginal delivery and planned cesarean delivery. Outcomes analyzed separately for the first and second twins were survival at discharge, survival at discharge without severe morbidity, and survival at 2 years of corrected age without neurosensory impairment.

RESULTS

Among the 932 women with a twin pregnancy, 549 were excluded mainly as a result of the first twin in noncephalic presentation, cause of delivery other than preterm labor or preterm prelabor rupture of membranes, at least one twin died before labor, and gestational age at delivery less than 24 weeks of gestation. The planned vaginal delivery group included 276 women and the planned cesarean delivery group 107. For first and second twins, survival at discharge (97.7% vs 98.3% and 95.6% vs 97.1%, respectively), survival at discharge without severe morbidity (91.6% vs 88.8% and 90.3% vs 84.5%, respectively), and survival at 2 years of corrected age without neurosensory impairment (96.0% vs 95.4% and 92.9% vs 90.8%, respectively) did not differ significantly between the planned vaginal delivery and planned cesarean delivery groups. Propensity score analysis showed that planned cesarean delivery was not associated with improved outcomes with the caveat that the infrequency of death and disability limited the statistical power of the study to detect potentially clinically meaningful differences between planned modes of delivery.

CONCLUSION

Planned cesarean delivery for women in preterm labor or with preterm prelabor rupture of membranes was not associated with improved neonatal outcomes or 2-year outcomes.

Combined Proinflammatory Biomarkers Have Better Predictive Value for Term Labor than Single Markers

BACKGROUND The timing of parturition is an important determinant of labor and delivery care. Early parturition is associated with increased neonatal morbidity and mortality. Most existing studies analyzed a single factor for the initiation of parturition, and the role of multiple factors in initiating parturition has not been comprehensively analyzed. MATERIAL AND METHODS We measured the levels of proinflammatory mediators, hypoxia factor, matrix metalloproteinases, hormones, and oxytocin, as well as fetal umbilical blood flow, before and after labor, and their associations with parturition. We also built a statistical model to predict the timing of parturition based on the measurement data. RESULTS IL-1ß, IL-6, TNF-alpha, MMP-9, and HIF-1alpha concentrations significantly increased from full term to labor. The PRL level significantly decreased from full term to parturition. There was no significant change in MCP-1, E3, and OT concentrations from full term to parturition. IL-1ß, IL-6, TNF-alpha, and MMP-9 concentrations were negatively correlated with the initiation of parturition. There was a small but nonsignificant increase in umbilical venous blood flow before parturition. Multiple factors showed a close correlation with the initiation of parturition, and area under the curve analysis showed that a multiple factor model was superior to single factors in the establishment of a model to predict initiation of parturition; however, these results need further confirmation. CONCLUSIONS Combined proinflammatory biomarkers have better predictive value for term labor than single biomarkers.

The impact of mode of delivery on the outcome in very preterm twins

Objective: Studies on the optimal mode of delivery in women with a twin pregnancy <32 weeks are scarce. We studied the effects of the mode of delivery on perinatal and maternal outcomes in very preterm twin pregnancy.Study Design: Population-based cohort study including all women with twin pregnancy who delivered very preterm (26-32 weeks of gestation) in the Netherlands between January 2000 and December 2010. We compared perinatal mortality and neonatal and maternal morbidity according to the intended mode of delivery as well as to the actual mode of delivery. Perinatal outcomes were paired taking into account the dependency between the children of the same twin pregnancy and were also analysed for each child separately. We used logistic regression to correct for possible confounding factors.Results: We studied 1,655 women with a very preterm delivery of a twin pregnancy. A planned caesarean section (n = 212) was associated with a significantly higher perinatal mortality compared to a planned vaginal delivery (n = 1.443) (10% compared to 6.5%; adjusted odds ratio (OR) 2.5, 95% confidence interval (CI) 1.5-4.2). The same applied for perinatal morbidity (66% compared to 63%; adjusted OR 1.5, 95% CI 1.1-2.0), maternal morbidity (17% compared to 4.9%; adjusted OR 4.0, 95% CI 2.6-6.3) and for perinatal mortality for the second twin (7.1% compared to 3.5% adjusted OR 2.9, 95% CI 1.7-5.2).Conclusion: In very preterm delivery of twins a vaginal delivery is the preferred mode of delivery.

Neonatal outcome of very preterm twins: policy of planned vaginal or cesarean delivery

OBJECTIVE

The objective of the study was to compare neonatal mortality and morbidity in very preterm twins with the first twin in cephalic presentation in hospitals with a policy of planned vaginal delivery (PVD) and those with a policy of planned cesarean delivery (PCD).

STUDY DESIGN

Women with preterm cephalic first twins delivered after preterm labor and/or premature preterm rupture of membranes from 26(0/7) to 31(6/7) weeks of gestation were identified from the databases of 6 perinatal centers and classified as PVD or PCD according to the center's management policy from 1999 to 2010. Severe neonatal morbidity was defined as any of the following: intraventricular hemorrhage grades 3-4, periventricular leukomalacia, necrotizing enterocolitis, bronchopulmonary dysplasia, and hospital death. The independent effect of the planned mode of delivery, defined by the center's management policy, was tested and quantified with a 2-level multivariable logistic regression.

RESULTS

The PVD group included 248 women, and the PCD group 63. Maternal characteristics did not differ between the 2 groups. The rate of vaginal delivery was 85.9% (213 of 248) vs 20.6% (13 of 63) (P < .001), and the rate of cesarean delivery for the second twin was 1.6% (4 of 248) vs 4.8% (3 of 63) (P = .13) for PVD and PCD. PVD had no independent effect on either newborn hospital mortality or severe neonatal composite morbidity.

CONCLUSION

A policy of planned vaginal delivery of very preterm twins with the first twin in cephalic presentation does not increase either severe neonatal morbidity or mortality.

Maternal antenatal complications and the risk of neonatal cerebral white matter damage and later cerebral palsy in children born at an extremely low gestational age

In a 2002-2004 prospective cohort study of deliveries of infants at <28 weeks at 14 US centers, the authors sought the antecedents of white matter damage evident in newborn cranial ultrasound scans (ventriculomegaly and an echolucent lesion) and of cerebral palsy diagnoses at age 2 years. Of the 1,455 infants enrolled, those whose mothers received an antenatal steroid tended to have lower risks of ventriculomegaly and an echolucent lesion than their peers (10% vs. 23%, P < 0.001 and 7% vs. 11%, P = 0.06, respectively). Risk of ventriculomegaly was increased for infants delivered because of preterm labor (adjusted odds ratio (OR) = 2.3, 95% confidence interval (CI): 1.1, 4.9), preterm premature rupture of fetal membranes (OR = 3.6, 95% CI: 1.5, 8.7), and cervical insufficiency (OR = 2.8, 95% CI: 1.4, 5.5) when compared with infants delivered because of preeclampsia. Risk of an echolucent lesion was increased for infants delivered because of preterm labor (OR = 2.7, 95% CI: 1.2, 5.7) and intrauterine growth retardation (OR = 3.3, 95% CI: 1.2, 9.4). The doubling of diparesis risk associated with preterm labor and with preterm premature rupture of fetal membranes did not achieve statistical significance, nor did the doubling of quadriparesis risk and the tripling of diparesis risk associated with cervical insufficiency.

Cystic periventricular leukomalacia in preterm infants: an analysis of obstetric risk factors

OBJECTIVE

To identify obstetric risk factors and to elucidate the effect of prolonged rupture of the membranes on the development of cystic periventricular leukomalacia (PVL) in preterm infants.

METHODS

A retrospective case-control study of 95 preterm infants with the diagnosis of PVL and 245 healthy controls matched for gestational age. A total of 52 antenatal, intrapartum and neonatal characteristics were studied by univariate methods and logistic regression.

RESULTS

Preterm premature rupture of membranes (PPROM) (odds ratio 2.1 [95% CI 1.3-3.4], P=.003), gestational age at PPROM (P=.025), prolonged rupture of membranes (P<.0001), administration of tocolytic agents (1.8 [1.1-3.0], P=.019) and antibiotics (1.9 [1.2-3.1], P=.008) were associated with PVL. The use of tocolytic agents >24 h (P=.008), prolonged latency between the increase in maternal leukocyte count and birth (P=.034), spontaneous onset of labor (1.8 [1.0-2.9], P=.026), vaginal delivery (1.7 [1.1-2.8], P=.029) and male gender (1.5 [1.0-2.0], P=.04) were found more frequently in PVL cases. Preeclampsia (0.4 [0.1-0.9], P=.034), hypertension at booking (P=.009), sonographic IUGR (P=.020), abnormal blood flow of the umbilical artery (P=.032) and cesarean section without labor (0.5 [0.3-0.8], P=.006) were found less frequently. In logistic regression analysis, prolonged rupture of the membranes (P=.748), preeclampsia (P=.973), the use of antibiotics (P=.617) and beta-sympathomimetic tocolytic agents (P=.563) lost statistical significance, whereas birth weight (P=.036) became significant.

CONCLUSION

PPROM and prolonged rupture of the membranes may provoke adverse effects on the neurodevelopmental outcome of the preterm fetus. These findings may have implications on the obstetric management of PPROM beyond 30 weeks of gestation. Cesarean section without labor was less likely associated with the diagnosis of PVL.

Antioxidant therapy and neuroprotection in the newborn

Injury to the perinatal brain is a leading cause of childhood mortality and lifelong disability. Despite recent improvements in neonatal care, no effective treatment for perinatal brain lesions is available. The newborn, especially if preterm, is highly prone to oxidative stress (OS) and to the toxic effect of free radicals (FRs). At birth, the newborn is exposed to a relatively hyperoxic environment caused by an increased oxygen bioavailability with greatly enhanced generation of FRs. Additional sources (e.g., inflammation, hypoxia, ischemia, glutamate and free iron release) occur, magnifying OS. In the preterm baby, the perinatal transition is accompanied by the immaturity of the antioxidant systems and the reduced ability to induce efficient homeostatic mechanisms designed to control overproduction of cell-damaging FRs. Improved understanding of the pathophysiological mechanism involved in perinatal brain lesions helps to identify potential targets for neuroprotective interventions, and the knowledge of these mechanisms has enabled scientists to develop new therapeutic strategies that have confirmed their neuroprotective effects in animal studies. Considering the growing role of OS in preterm newborn morbidity in respect to the higher risk of FR damage in these babies, erythropoietin, allopurinol, melatonin and hypothermia demonstrate great promise as potential neuroprotectans. This article provides an overview of the pathogenesis of FR-mediated diseases of the newborn and the antioxidant strategies now tested in order to reduce OS and its damaging effects.