High compared with standard gentamicin dosing for chorioamnionitis: a comparison of maternal and fetal serum drug levels

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.

Neonatal Serum Gentamicin Concentrations and Outcomes Following Maternal Once-Daily Gentamicin Dosing

OBJECTIVE

This study evaluated newborn gentamicin serum concentrations after birth and the effects on the newborn after extended interval gentamicin dosing in peripartum mothers.

METHODS

This was a single-center, retrospective chart review of neonates born to mothers that received peripartum once-daily gentamicin dosing of approximately 5 mg/kg within 12 hours of delivery. A gentamicin serum concentration was obtained immediately after birth in the newborn. The primary outcome was initial neonatal gentamicin serum concentration after birth. Several secondary outcomes were evaluated including nephrotoxicity and ototoxicity. A subgroup analysis comparing baseline demographics of mother-newborn dyads with birth neonatal serum concentrations of less than 2 mcg/mL versus 2 mcg/mL or greater was performed.

RESULTS

A total of 32 mother-newborn dyads were included. Newborns had a median gestational age of 39.4 weeks and median birth weight of 3.4 kg. The mean initial gentamicin serum concentration was elevated at 3.1 ± 1.9 mcg/mL among all newborns. The median maternal dose based on actual body weight in newborns with gentamicin serum concentrations less than 2 mcg/mL was 3.5 (IQR, 3.3-4.8) mg/kg versus 4.8 (IQR, 4.3-5.2) mg/kg in those that had serum concentrations of 2 mcg/mL or greater (p = 0.025). All newborn gentamicin serum concentrations were less than 2 mcg/mL for maternal doses given less than 1 hour prior to delivery (n = 8). There were no significant differences in nephrotoxicity or ototoxicity.

CONCLUSIONS

Peripartum once daily dosing of gentamicin administered between 1 to 12 hours of birth may lead to clinically significant serum concentrations in newborns.

Understanding the pharmacokinetics of antibiotics in pregnancy: Is there a role for therapeutic drug monitoring? A narrative review

PURPOSE

Antibiotics are commonly used during pregnancy. However, physiological changes during pregnancy can affect the pharmacokinetics of drugs, including antibiotics, used during this period. Pharmacokinetic evaluations have shed light on how antibiotics are affected during pregnancy and have influenced dosing recommendations in this context. Methods: A narrative review was conducted and included reports providing data reflecting drug distribution and exposure in the context of pregnancy. Results: Pharmacokinetic parameters of antibiotics in pregnancy and transplacental passage of antibiotics are comprehensively presented. Conclusion: Knowledge about the impact on pharmacokinetics and fetal exposure is especially helpful for complicated or severe infections, including intra-amniotic infection and sepsis in pregnancy, where both mother and fetus are at risk. Further studies are warranted to consolidate the role of therapeutic drug monitoring in complicated or severe infections in pregnant patients.

Determining the optimal antibiotic regimen for chorioamnionitis: A systematic review and meta-analysis

INTRODUCTION

To evaluate the effect of antibiotic regimens for chorioamnionitis on maternal and neonatal outcomes.

MATERIAL AND METHODS

We conducted a systematic review, wherein we searched six bibliographic databases until June 2020 and included randomized clinical trials describing antibiotic regimens for treating chorioamnionitis. Risk of bias was assessed using the Cochrane Risk of Bias tool V2.0. Random-effects meta-analysis was performed and results were presented as risk ratio (RR) and mean differences (MD) with 95% CI.

RESULTS

Fourteen trials at low-to-high risk of bias were included. Three trials (n = 244), comparing different intrapartum antibiotic regimens, showed no difference in outcomes except for lower composite maternal morbidity (endometritis, pneumonia, sepsis, blood transfusion, and ileus) with ampicillin/sulbactam vs ampicillin/gentamicin in one study (0/43 vs 6/49, P = .03). Three trials (n = 295) comparing different doses of intrapartum antibiotics showed no differences in maternal and neonatal outcomes, although one study showed a shorter duration of antibiotic treatment in the experimental arm (4 mg/kg gentamicin q24h + 1200 mg clindamycin q12h) vs conventional arm (1.33 mg/kg gentamicin + 800 mg clindamycin q8h) (48.0 ± 36 hours vs 55.2 ± 48 hours, P = .04). Four trials (n = 484) comparing postpartum antibiotics vs no antibiotics showed no difference in outcomes except for a shorter hospital stay (two studies, MD -7.90 hours, 95% CI -13.52 to -2.27 hours). Three trials (n = 447) comparing single vs multiple doses of postpartum antibiotics showed shorter hospital stay [MD -19.14 hours, 95% CI -29.88 to -8.41 hours), but no differences in treatment failure (RR 1.73, 95% CI 0.69-4.30) or total antibiotic dose (MD -9.24, 95% CI -19.49 to 1.01). One trial (n = 48) comparing intrapartum vs postpartum initiation of treatment found benefits to intrapartum (vs postpartum) initiation of antibiotics, in terms of postpartum maternal hospital stay (MD -24 hours, 95% CI -45.56 to -1.44 hours), neonatal hospital stay (MD -45.6 hours, -93.84 to -11.76 hours), and neonatal pneumonia or sepsis (RR 0.06, 95% CI 0.00-0.95).

CONCLUSIONS

Upon diagnosis of chorioamnionitis, there is limited evidence to recommend the prompt initiation of intrapartum antibiotics, and to consider a single dose of postpartum antibiotics over multiple doses or no treatment. Well-designed trials using standard definitions of chorioamnionitis, outcome measures, and newer antibiotics are required to inform clinical practice with regard to the preferred antibiotic regimen, dose, and duration to optimize maternal and neonatal outcomes.

Development of amoebic liver abscess in early pregnancy years after initial amoebic exposure: a case report

BACKGROUND

Infection with Entamoeba histolytica and associated complications are relatively rare in developed countries. The overall low prevalence in the Western world as well as the possibly prolonged latency period between infection with the causing pathogen and onset of clinical symptoms may delay diagnosis of and adequate treatment for amoebiasis. Amoebic liver abscess (ALA) is the most common extraintestinal manifestation of invasive amoebiasis. Pregnancy has been described as a risk factor for development of invasive amoebiasis and management of these patients is especially complex.

CASE PRESENTATION

A 30-year-old Caucasian woman in early pregnancy presented to our emergency department with abdominal pain alongside elevated inflammatory markers and liver function tests. Travel history revealed multiple journeys to tropic and subtropic regions during the past decade and a prolonged episode of intermittently bloody diarrhea during a five month stay in Indonesia seven years prior to admission. Sonographic and magnetic resonance imaging revealed a 5 × 4 cm hepatic abscess. After ultrasound-guided transcutaneous liver drainage, both abscess fluids and blood cultures showed neither bacterial growth nor microscopic signs of parasitic disease. Serological testing confirmed an infection with Entamoeba histolytica, which was treated with metronidazole, followed by eradication therapy with paromomycin. Subsequent clinical, laboratory and imaging follow-up exams showed regression of the ALA. In addition, the pregnancy completed without complications and a healthy baby boy was born 7 months after termination of treatment.

CONCLUSIONS

This case of invasive amoebiasis in early pregnancy outside of endemic regions and several years after exposure demonstrates the importance of broad differential diagnostics in the context of liver abscesses. The complex interdisciplinary decisions regarding the choice of imaging techniques as well as interventional and antibiotic therapy in the context of pregnancy are discussed. Furthermore, we present possible explanations for pregnancy as a risk factor for an invasive course of amoebiasis.

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.

The transplacental passage of commonly used intrapartum antibiotics and its impact on the newborn management: A narrative review

Neonates exposed to intra-amniotic infection are at increased risk of early-onset sepsis. Administration of antibiotics to the mother may offer some protection, however a comprehensive description of the determinants influencing their transplacental passage and delivery to the fetus has not been performed. While penicillin G, ampicillin, cefazolin and gentamicin reach therapeutic levels in the fetal serum rapidly following maternal administration, the transfer of second-line intrapartum antimicrobials, such as vancomycin and clindamycin, is slower and less predictable. Erythromycin, used in the context of preterm premature rupture of the membranes, has suboptimal influx into the fetal compartment. This evidence is predominantly drawn from term pregnancies and situations of low infectious risk; however, prematurity may negatively influence fetal exposure to intrapartum antibiotics. Optimal fetal antimicrobial concentrations to target are poorly defined and the extent to which our review findings apply to preterm early-onset neonatal sepsis prevention is unclear. Interpretation of blood cultures drawn in neonates with expected circulating levels of maternal antimicrobials above the minimal inhibitory concentration for Group B Streptococcus is challenging despite the use of contemporary optimized blood culture media.

Daily gentamicin using ideal body weight demonstrates lower risk of postpartum endometritis and increased chance of successful outcome compared with traditional 8-hour dosing for the treatment of intrapartum chorioamnionitis

Background: Clinical chorioamnionitis complicates approximately 1-4% of pregnancies overall. Although universal agreement does not exist regarding the antibiotic regimen of choice, most studies have evaluated intravenous ampicillin dosed at 2 g every 6 hours plus gentamicin dosed every 8 hours. Only three studies have examined daily gentamicin for the treatment of intrapartum chorioamnionitis and thus is insufficiently investigated. Objective: This study seeks to determine whether daily dosing of gentamicin using ideal body weight for the treatment of intrapartum chorioamnionitis is more or equivalently efficacious when compared to traditional 8-hour dosing regimens. Materials and methods: We conducted a retrospective cohort study and reviewed charts on all women receiving treatment for intrapartum chorioamnionitis, which included intravenous gentamicin daily dosing calculated using 5 mg/kg ideal body weight or receiving traditional every 8 hours dosing of gentamicin at two large academic centers. Our primary outcomes were resolution of infection following delivery without the development of maternal endometritis and/or neonatal sepsis. Baseline characteristics were compared between dosing groups using Welch two-sample t-tests for continuous variables, uncorrected X² test and exact binomial 95% confidence intervals. We calculated the risk ratios of each outcome in the ideal versus traditional dosing groups using modified Poisson regression, both crude and adjusted. Adjusted models were controlled for variables determined to be potential confounders, which included BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34 y), and parity. Results: The study included 500 patients with 255 patients receiving daily dosing of gentamicin and 245 receiving traditional dosing of gentamicin. Of the patients receiving daily gentamicin compared to traditional dosing, 95.7% (95% CI 94.9-96.6%) achieved the primary outcome versus 92% (95% CI 90.8 - 93.2%), 2.4% (95% CI 1.8-3%) developed endometritis versus 5.6% (4.5-6.7%), 1.6% (95% CI 1.1-2.1%) delivered neonates with sepsis versus 3.3% (CI 2.5-4.1%), and 36.9% required cesarean delivery versus 41.4%. In crude analysis, compared to traditional dosing, IDW daily dosing was associated with a lower risk of postpartum endometritis (RR 0.42, 95% CI 0.16-1.10, p = .032). After adjusting for BMI, diabetes mellitus, gestational blood pressure >140/90, group β-Streptococcus status, race, advanced maternal age (>34 y), and parity, the IDW daily dosing group had a 5% greater chance of successful outcome (RR 1.05, 95% CI 1.00-1.10, p = .046) and a 64% lower risk of endometritis (RR 0.35, 95% CI 0.15-0.83, p = .017). Conclusion: Daily dosing of gentamicin using ideal body weight is associated with a lower risk of postpartum endometritis and high chance of a successful outcome in the treatment of intrapartum chorioamnionitis compared with traditional 8-hour dosing in our ethnically diverse, urban population and thus may be considered a superior option to every 8 hours dosing regimens.

Committee Opinion No. 645: Dual Therapy for Gonococcal Infections

Gonorrhea is the second most commonly reported bacterial sexually transmitted disease in the United States, with an estimated 820,000 new Neisseria gonorrhoeae infections occurring each year. Antimicrobial resistance limits treatment success, heightens the risk of complications, and may facilitate the transmission of sexually transmitted infections. Neisseria gonorrhoeae has developed resistance to the sulfonamides, the tetracyclines, and penicillin. Dual therapy with ceftriaxone and azithromycin remains the only recommended first-line regimen for the treatment of gonorrhea in the United States. Dual therapy with ceftriaxone and azithromycin should be administered together on the same day, preferably simultaneously, and under direct observation. Pregnant women who are infected with N gonorrhoeae should be treated with the recommended dual therapy. A test-of-cure is not needed for individuals diagnosed with uncomplicated urogenital or rectal gonorrhea who are treated with the recommended or alternative regimens. Repeat N gonorrhoeae infection is prevalent among patients who have been diagnosed with and treated for gonorrhea in the preceding several months. Most of these infections result from reinfection; therefore, clinicians should advise patients with gonorrhea to be retested 3 months after treatment. Pregnant women with antenatal gonococcal infection should be retested in the third trimester unless recently treated.

Daily dosing of gentamicin using ideal body weight for the treatment of intrapartum chorioamnionitis: a pilot study

PURPOSE

This study aimed to determine whether daily dosing of gentamicin using ideal body weight in the treatment of chorioamnionitis is effective.

MATERIALS AND METHODS

We conducted a prospective observational study and followed all women receiving treatment for chorioamnionitis which included gentamicin daily dosing calculated using 5 mg/kg ideal body weight. Patients were excluded if pathological analysis of placenta did not confirm chorioamnionitis. Our primary outcome was resolution of infection following delivery without the development of maternal endometritis and/or neonatal sepsis. Ninety-five percent confidence intervals for proportions were calculated using exact binomial tests. These patients were retrospectively compared to patients who received treatment for chorioamnionitis which included traditional gentamicin every 8 h.

RESULTS

The study included 160 patients. Of the patients receiving daily dosing (n = 80) compared to traditional dosing (n = 80), 96% (95% CI 95.7-97.6%) achieved the primary outcome versus 91% (88.9-93.1%), 2.5% (95% CI 1.2-3.8%) developed endometritis versus 6.3% (4.2-8.4%), 1.3% (95% CI 0.4-2.2%) delivered neonates with sepsis versus 2.5% (1.2-3.8%), and 39% required cesarean delivery (95% CI 46.2-53.8) versus 37% (33.2-40.8%).

CONCLUSION

Daily dosing of gentamicin using ideal body weight is effective in successful treatment of chorioamnionitis without development endometritis and/or neonatal sepsis across different ethnicities.

Antibiotic regimens for management of intra-amniotic infection

BACKGROUND

Chorioamnionitis is a common infection that affects both mother and infant. Infant complications associated with chorioamnionitis include early neonatal sepsis, pneumonia, and meningitis. Chorioamnionitis can also result in maternal morbidity such as pelvic infection and septic shock.Clinical chorioamnionitis is estimated to occur in 1% to 2% of term births and in 5% to 10% of preterm births; histologic chorioamnionitis is found in nearly 20% of term births and in 50% of preterm births. Women with chorioamnionitis have a two to three times higher risk for cesarean delivery and a three to four times greater risk for endomyometritis, wound infection, pelvic abscess, bacteremia, and postpartum hemorrhage.

OBJECTIVES

To assess the effects of administering antibiotic regimens for intra-amniotic infection on maternal and perinatal morbidity and mortality and on infection-related complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2014), CENTRAL, MEDLINE, Embase, LILACS, and the WHO ICTRP (September 2014). We also searched reference lists of retrieved studies and contacted experts in the field.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that included women who experienced intra-amniotic infection. Trials were included if they compared antibiotic treatment with placebo or no treatment (if applicable), treatment with different antibiotic regimens, or timing of antibiotic therapy (intrapartum and/or postpartum). Therefore, this review assesses trials evaluating intrapartum antibiotics, intrapartum and postpartum antibiotic regimens, and postpartum antibiotics. Diagnosis of intra-amniotic infection was based on standard criteria (clinical/test), and no limit was placed on gestational age.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality. Two review authors independently extracted data and checked them for accuracy. We assessed the quality of the evidence using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach and included a 'Summary of findings' table.

MAIN RESULTS

Our prespecified primary outcomes were maternal and neonatal mortality, maternal and neonatal severe infection, and duration of maternal and neonatal hospital stay.We included 11 studies (involving 1296 women) and assessed them as having low to moderate risk of bias - mainly because allocation concealment methods were not adequately reported, most studies were open, and outcome reporting was incomplete. The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. The following antibiotics were assessed in the included trials: ampicillin, ampicillin/sulbactam, gentamicin, clindamycin, and cefotetan. During labor: meta-analysis of two studies found no clear differences in rates of neonatal sepsis (163 neonates; risk ratio (RR) 1.07, 95% confidence interval (CI) 0.40 to 2.86; I² = 9%; low quality of evidence), treatment failure (endometritis) (163 participants; RR 0.86, 95% CI 0.27 to 2.70; I² = 0%; low quality of evidence), and postpartum hemorrhage (RR 1.39, 95% CI 0.76 to 2.56; I² = 0%; low quality of evidence) when two different dosages/regimens of gentamicin were assessed. No clear differences between groups were found for any reported maternal or neonatal outcomes. The review did not identify data for a comparison of antibiotics versus no treatment/placebo. Postpartum: meta-analysis of two studies that evaluated use of antibiotics versus placebo after vaginal delivery showed no significant differences between groups in rates of treatment failure or postpartum endometritis. No significant differences were found in rates of neonatal death and postpartum endometritis when use of antibiotics was compared with no treatment. Four trials assessing two different dosages/regimens of gentamicin or dual-agent therapy versus triple-agent therapy, or comparing antibiotics, found no significant differences in most reported neonatal or maternal outcomes; the duration of hospital stay showed a difference in favor of the group of women who received short-duration antibiotics (one study, 292 women; mean difference (MD) -0.90 days, 95% CI -1.64 to -0.16; moderate quality of evidence). Intrapartum versus postpartum: one small study (45 women) evaluating use of ampicillin/gentamicin during intrapartum versus immediate postpartum treatment found significant differences favoring the intrapartum group in the mean number of days of maternal postpartum hospital stay (one trial, 45 women; MD -1.00 days, 95% CI -1.94 to - 0.06; very low quality of evidence) and the mean number of neonatal hospital stay days (one trial, 45 neonates; MD -1.90 days, 95% CI -3.91 to -0.49; very low quality of evidence). Although no significant differences were found in the rate of maternal bacteremia or early neonatal sepsis, for the outcome of neonatal pneumonia or sepsis we observed a significant difference favoring intrapartum treatment (one trial, 45 neonates; RR 0.06, 95% CI 0.00 to 0.95; very low quality of evidence).

AUTHORS' CONCLUSIONS

This review included 11 studies (having low to moderate risk of bias). The quality of the evidence was low to very low for most outcomes, as per the GRADE approach. Only one outcome (duration of hospital stay) was considered to provide moderate quality of evidence when antibiotics (short duration) were compared with antibiotics (long duration) during postpartum management of intra-amniotic infection. Our main reasons for downgrading the quality of evidence were limitations in study design or execution (risk of bias), imprecision, and inconsistency of results.Currently, limited evidence is available to reveal the most appropriate antimicrobial regimen for the treatment of patients with intra-amniotic infection; whether antibiotics should be continued during the postpartum period; and which antibiotic regimen or what treatment duration should be used. Also, no evidence was found on adverse effects of the intervention (not reported in any of the included studies). One small RCT showed that use of antibiotics during the intrapartum period is superior to their use during the postpartum period in reducing the number of days of maternal and neonatal hospital stay.

Renal teratogens

In utero exposure to certain drugs early in pregnancy may adversely affect nephrogenesis. Exposure to drugs later in pregnancy may affect the renin-angiotensin system, which could have an impact on fetal or neonatal renal function. Reduction in nephron number and renal function could have adverse consequences for the child several years later. Data are limited on the information needed to guide decisions for patients and providers regarding the use of certain drugs in pregnancy. The study of drug nephroteratogenicity has not been systematized, a large, standardized, global approach is needed to evaluate the renal risks of in utero drug exposures.

Evidence for the clinical management of chorioamnionitis

Acute chorioamnionitis or intra-amniotic infection is defined by maternal fever in association with at least one additional clinical criterion including maternal or fetal tachycardia, maternal leukocytosis, uterine tenderness, or foul amniotic fluid odor. In clinically uncertain cases, the diagnosis can be augmented by routine laboratory studies (e.g. white blood cell count and differential count and acute phase reactants) and assays done on amniotic fluid. In general, the clinical management of chorioamnionitis is based on observational or cohort studies; only a few randomized controlled trials have been done. Prompt administration of antibiotics and delivery decrease maternal and neonatal morbidity. The most commonly used antibiotic regimen is ampicillin and gentamicin. Recent evidence supports daily rather than three-times-daily dosing of gentamicin for greater efficacy and decreased fetal toxicity. There is no evidence demonstrating harm with the administration of corticosteroids (to promote fetal lung maturity) in women with acute chorioamnionitis. Cesarean delivery should be reserved for standard obstetric indications.

Antibiotic Treatment of Dogs and Cats during Pregnancy

The use of pharmacological agents in pregnant females poses a major clinical challenge due to the marked physiological changes that may modify the pharmacokinetics of drugs and to the potential effects on the fetus. The purpose of this paper is to review briefly our knowledge on the use of antibacterial drugs during pregnancy and to provide information for the judicious selection of an antimicrobial treatment for use in pregnant bitches and queens. The risk to the fetus is a result of the ability of a drug to reach the fetal circulation and to produce toxic effects. The placenta functions as a barrier that protects the fetus due to the presence of transporters and metabolising enzymes; however, during pregnancy, the presence and activity of both enzymes and transporters may change. Antimicrobial agents that have been shown to be safe for use during pregnancy include betalactams, macrolides, and lincosamides. Pharmacotherapy during pregnancy in all species may affect adversely the developing fetus; therefore, it should be avoided when possible.

Diagnosis and management of clinical chorioamnionitis

Chorioamnionitis is a common complication of pregnancy associated with significant maternal, perinatal, and long-term adverse outcomes. Adverse maternal outcomes include postpartum infections and sepsis whereas adverse infant outcomes include stillbirth, premature birth, neonatal sepsis, chronic lung disease, and brain injury leading to cerebral palsy and other neurodevelopmental disabilities. Research in the past 2 decades has expanded understanding of the mechanistic links between intra-amniotic infection and preterm delivery as well as morbidities of preterm and term infants. Recent and ongoing clinical research into better methods for diagnosing, treating, and preventing chorioamnionitis is likely to have a substantial impact on short and long-term outcomes in the neonate.

Once-daily dosing of gentamicin in obstetrics and gynecology

Gentamicin, an aminoglycoside with broad antimicrobial activity, is commonly used in both obstetrics and gynecology. Traditional dosing regimens for gentamicin have called for 3 times daily dosing, but recent insights into the pharmacodynamics of the drug have led to multiple studies of once-daily dosing regimens. Many studies have demonstrated efficacy, safety, and economy of the 24-hour dosing interval, resulting in recommendations that this become the standard for aminoglycoside administration. However, because of the unique considerations for drug administration in pregnant and postpartum women, the once-daily dosing regimens have not been widely adopted. Additional studies in pregnant and postpartum women have demonstrated therapeutic noninferiority, no increase in adverse events, and significant cost savings with once-daily dosing versus 3 times daily dosing of gentamicin. We review the literature and present rationale based on multiple controlled studies supporting single-daily dosing of gentamicin, 5 mg/kg/d actual body weight, for many common obstetrics-gynecology infections.

Is Gentamicin Ototoxic to the Fetus?

BACKGROUND

Gentamicin is used in pregnancy to treat infections that cause complications to the mother and fetus if left untreated. In 2003, Schering, the manufacturer of Garamycin Injectable, amended the product monograph in the Compendium of Pharmaceuticals and Specialties to state that gentamicin should be avoided in pregnancy due to cases of "total irreversible bilateral congenital deafness" in babies exposed to gentamicin in utero. Because we have identified, after an intensive literature search, only two cases over many years of availability, it is questionable whether the outcome can be attributed to drug use rather than other factors.

OBJECTIVES

The main objective of this study was to determine whether any infant exposed in utero to intravenous gentamicin and born between January 2002 and April 2006 at Victoria General Hospital demonstrated audiologic deficits on routine hearing testing. Such testing has been universally available since late 2001. Our secondary objectives were to examine patterns of gentamicin use, including indication, dosage, duration, and to determine whether or not monitoring of serum gentamicin levels was done.

METHODS

Women who had received gentamicin were identified through pharmacy records and their charts reviewed for factors that might contribute to fetal deafness including substance abuse, use of other potentially ototoxic medications, genetic predisposition, and intrauterine infections. We reviewed audiology test result and the infants' charts for potential confounding factors, including prematurity, low birth weight, low Apgar scores, anoxia, hyperbilirubinemia, sepsis, and meningitis.

RESULTS

Fifty-two charts were reviewed, 40 of which documented live births. There was no case of hearing loss documented. Of the eight fetal losses, six (11.5%) were preterm births before viability, and two were elective terminations. Pyelonephritis was the main indication for gentamicin use (48%), followed by chorioamnionitis (31%) and other miscellaneous indications (21%). Three times daily dosing was used for a mean duration of 2.7 +- 2.3 days, resulting in an average cumulative dose of 764 +- 600 mg gentamicin. The average gestational age at exposure was 28 weeks. Maternal serum gentamicin levels were obtained in 72.5% of cases, and no trough level was above 2 mg/L. Other potentially ototoxic medications were administered to the mother in 17.5% of pregnancies, and to 17.5% of babies in the immediate newborn period. With the exception of one infant who died before additional testing could be carried out, all the infants passed hearing tests, 89% on initial screening.

CONCLUSION

In utero exposure to gentamicin did not cause an increase in audiologic impairment in the infants tested in this cohort.

Effects of maternally administered drugs on the fetal and neonatal kidney

The number of pregnant women and women of childbearing age who are receiving drugs is increasing. A variety of drugs are prescribed for either complications of pregnancy or maternal diseases that existed prior to the pregnancy. Such drugs cross the placental barrier, enter the fetal circulation and potentially alter fetal development, particularly the development of the kidneys. Increased incidences of intrauterine growth retardation and adverse renal effects have been reported. The fetus and the newborn infant may thus experience renal failure, varying from transient oligohydramnios to severe neonatal renal insufficiency leading to death. Such adverse effects may particularly occur when fetuses are exposed to NSAIDs, ACE inhibitors and specific angiotensin II receptor type 1 antagonists. In addition to functional adverse effects, in utero exposure to drugs may affect renal structure itself and produce renal congenital abnormalities, including cystic dysplasia, tubular dysgenesis, ischaemic damage and a reduced nephron number. Experimental studies raise the question of potential long-term adverse effects, including renal dysfunction and arterial hypertension in adulthood. Although neonatal data for many drugs are reassuring, such findings stress the importance of long-term follow-up of infants exposed in utero to certain drugs that have been administered to the mother.

Drug therapy during labor and delivery, part 1

PURPOSE

The drug therapy of common conditions and complications during labor and delivery and the fetal and neonatal effects of this therapy are examined.

SUMMARY

The pharmacologic therapy of common conditions that occur in labor and delivery primarily involves oxytocin and prostaglandins for cervical ripening and labor induction and systemic and regional narcotic analgesics for pain. Because most medications used in women during labor and delivery do not have Food and Drug Administration-approved labeling, pharmacists should understand the benefits and limitations of medications used in the mother. Although induction and augmentation of labor and the control of pain often require drug therapy, other, less frequent, complications may occur in labor. Drug therapies for these complications include anti-infective agents to treat maternal infection and prevent neonatal diseases; antiretrovirals to reduce perinatal HIV-1 transmission from the mother to the fetus; corticosteroids to prevent fetal lung immaturity; antihypertensives to treat preeclampsia; anticonvulsants to treat eclampsia; antibiotics to prolong pregnancy and improve neonatal outcomes after premature rupture of the membranes; tocolytics for premature labor; and oxytocin, ergot alkaloids, and prostaglandin analogues for postpartum hemorrhage. The fetal and neonatal effects of therapy for the conditions that occur during labor and delivery are usually benign, but significant morbidity and mortality involving the mother, the fetus, and the newborn are ever-present risks.

CONCLUSION

Awareness of the conditions and complications requiring drug therapy during labor and delivery will allow hospital pharmacists to make knowledgeable decisions about the rapid accessibility of critical medications in the labor and delivery unit.

Antibiotic regimens for management of intraamniotic infection

BACKGROUND

Intraamniotic infection is associated with maternal morbidity and neonatal sepsis, pneumonia and death. Although antibiotic treatment is accepted as the standard of care, few studies have been conducted to examine the effectiveness of different antibiotic regimens for this infection and whether to administer antibiotics intrapartum or postpartum.

OBJECTIVES

To study the effects of different maternal antibiotic regimens for intraamniotic infection on maternal and perinatal morbidity and mortality.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (May 2002) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002).

SELECTION CRITERIA

Trials where there was a randomized comparison of different antibiotic regimens to treat women with a diagnosis of intraamniotic infection were included. The primary outcome was perinatal morbidity.

DATA COLLECTION AND ANALYSIS

Data were extracted from each publication independently by the authors.

MAIN RESULTS

Two eligible trials (181 women) were included in this review. No trials were identified that compared antibiotic treatment with no treatment. Intrapartum treatment with antibiotics for intraamniotic infection was associated with a reduction in neonatal sepsis (relative risk (RR) 0.08; 95% confidence interval (CI) 0.00, 1.44) and pneumonia (RR 0.15; CI 0.01, 2.92) compared with treatment given immediately postpartum, but these results did not reach statistical significance (number of women studied = 45). There was no difference in the incidence of maternal bacteremia (RR 2.19; CI 0.25, 19.48). There was no difference in the outcomes of neonatal sepsis (RR 2.16; CI 0.20, 23.21) or neonatal death (RR 0.72; CI 0.12, 4.16) between a regimen with and without anaerobic activity (number of women studied = 133). There was a trend towards a decrease in the incidence of post-partum endometritis in women who received treatment with ampicillin, gentamicin and clindamycin compared with ampicillin and gentamicin alone, but this did not reach statistical significance (RR 0.54; CI 0.19, 1.49).

REVIEWER'S CONCLUSIONS

The conclusions that can be drawn from this meta-analysis are limited due to the small number of studies. For none of the outcomes was a statistically significant difference seen between the different interventions. Current consensus is for the intrapartum administration of antibiotics when the diagnosis of intraamniotic infection is made; however, the results of this review neither support nor refute this although there was a trend towards improved neonatal outcomes when antibiotics were administered intrapartum. No recommendations can be made on the most appropriate antimicrobial regimen to choose to treat intraamniotic infection.