Therapies administered to mothers at risk for preterm birth and neurodevelopmental outcome in their infants

Diagnosis and Treatment of Equine Placentitis

Equine placentitis is a complex disease that has devastating consequences for horse owners. Placentitis is a significant cause of foal loss annually. Prompt diagnosis and treatment of the disease are paramount for survival of the affected neonate. This article discusses current information on pathogenesis of the disease as well as diagnostic and therapeutic options.

Treatment strategies for mares with placentitis

Equine placentitis, and resultant preterm labor, are important sources of fetal and neonatal loss. The primary cause of equine placentitis is infection of the placenta with Streptococcus equi subspecies zooepidemicus, which ascends through the caudal reproductive tract. Current treatment protocols for mares affected with placentitis are empirical. This paper reviews treatment approaches for resolving placentitis and preterm labor in both equine and non-equine species. Specific therapies reviewed include antimicrobial, anti-inflammatory, tocolytic, and progestin agents.

What is the future of tocolysis?

Use of the currently available tocolytics is controversial because it has not been associated with improved perinatal outcomes. New markers of preterm labour may come from gene-profiling studies, in as much as they may help in identifying novel genes regulating myometrial quiescence and in expanding our understanding of the pathologic process of uterine dysfunction. Study of certain transcripts in circulating white blood cells by RT-PCR could assist the obstetrician in evaluation of the risks. Uterine electromyography (EMG) also has the potential benefit of monitoring tocolytic treatment, although no standard method of clinical interpretation has yet been devised for the results yielded by this instrumentation. Recent functional genomic studies found that in the uterus at term there is a massive down-regulation of a large panel of developmental cell adhesion molecules and proliferation-related genes. Conversely, maintaining the developmental processes in an active state in patients at risk would help to prevent preterm delivery. It is too early to suggest any therapies with anticytokines in pregnant women. However, exploration of genetic polymorphisms, which may influence the balance of pro- and anti-inflammatory cytokines that are relevant to the course of preterm labour, seems to be a novel avenue that should be explored.

The Randomized Nitric Oxide Tocolysis Trial (RNOTT) for the treatment of preterm labor

OBJECTIVE

This study was undertaken to assess the effectiveness of glyceryl trinitrate (GTN) patches in comparison with beta2 sympathomimetics (beta2) for the treatment of preterm labor.

STUDY DESIGN

A multicenter, multinational, randomized controlled trial was conducted in tertiary referral teaching hospitals. Women in threatened preterm labor with positive fetal fibronectin or ruptured membranes between 24 and 35 weeks' gestation were recruited and randomly assigned to either beta2 or GTN with rescue beta2 tocolysis if moderate-to-strong contractions persisted at 2 hours. Obstetric and neonatal outcomes were assessed.

RESULTS

Two hundred thirty-eight women were recruited and randomly assigned, 117 to beta2 and 121 to GTN. On a strict intention-to-treat basis, there was no significant difference in the time to delivery using Kaplan-Meier curves (P = .451). At 2 hours, 27% of women receiving beta2 had moderate or stronger contractions compared with 53% in the GTN group (P < .001). This led to 35% of women in the GTN group receiving rescue treatment. If delivery or requirement for beta2 rescue are regarded as treatment failure, then a significant difference was observed between the 2 arms (P = .0032). There were no significant differences in neonatal outcomes.

CONCLUSION

GTN is a less efficacious tocolytic compared with ss2 sympathomimetics.