Ronald S. Gibbs

Chorioamnionitis and bacterial vaginosis

An improved understanding of bacterial vaginosis and of clinical intraamniotic infection and histologic chorioamnionitis has produced data showing strong associations among these conditions. It has recently been shown that the microorganisms in both bacterial vaginosis and clinical intraamniotic infection are similar, of which anaerobes, Gardnerella vaginalis, and Mycoplasma hominis are the predominant organisms in both. Furthermore, in the amniotic fluid of women with intraamniotic infection, strong associations among anaerobes, G. vaginalis, and M. hominis have recently been observed. In two epidemiologic studies (one in a high-risk group of women in labor and another in a lower risk group of antepartum women), the presence of bacterial vaginosis has been associated with the development of intraamniotic infection. Additional recent studies have provided new evidence that histologic inflammation of the placental membranes is associated with both clinical intraamniotic infection and positive cultures of the placenta. Multiple logistic regression analysis has shown a relationship between isolation of organisms from the chorioamnion and bacterial vaginosis.

Shotgun Proteomic Analysis of Vaginal Fluid From Women in Late Pregnancy

Liquid chromatography and tandem mass spectrometry without prior fractionation (shotgun proteomics) were used to analyze vaginal fluid from patients admitted for signs and symptoms of preterm labor. The patients had an average age of 26.3 ± 5.9 years, a gestational age of 30.5 ± 2.5 weeks, and a median cervical dilation of 1 cm (range, 0-6 cm). None of the patients exhibited signs of vaginal infection at the time of enrollment. Shotgun proteomics yielded reproducible identifications (R = 0.973) of more than 40 proteins in vaginal fluid samples, such as plasma proteins, epithelial structural proteins, and several immunoregulatory proteins, including some that were previously linked to intra-amniotic infection. This initial characterization of the vaginal fluid proteome using a nonbiased, high-throughput technique yields reproducible results in late pregnancy. The presence of host defense proteins in vaginal fluid suggests that this technique may be useful for future study of inflammation-related preterm birth.

The clinical content of preconception care: infectious diseases in preconception care.

A number of infectious diseases should be considered for inclusion as part of clinical preconception care. Those infections strongly recommended for health promotion messages and risk assessment or for the initiation of interventions include Chlamydia infection, syphilis, and HIV. For selected populations, the inclusion of interventions for tuberculosis, gonorrheal infection, and herpes simplex virus are recommended. No clear evidence exists for the specific inclusion in preconception care of hepatitis C, toxoplasmosis, cytomegalovirus, listeriosis, malaria, periodontal disease, and bacterial vaginosis (in those with a previous preterm birth). Some infections that have important consequences during pregnancy, such as bacterial vaginosis (in those with no history of preterm birth), asymptomatic bacteriuria, parvovirus, and group B streptococcus infection, most likely would not be improved through intervention in the preconception time frame.

Obstetric Factors Associated with Infections in the Fetus and Newborn Infant

Early-onset neonatal infection often has its origin in utero. Thus, risk factors for neonatal sepsis include prematurity, premature rupture of the membranes (PROM), and maternal fever during labor (which may be caused by clinical intra-amniotic infection). This chapter focuses on these major obstetric conditions. Included in addition to these three “classic” topics is a discussion of new information indicating that intrauterine exposure to bacteria is linked to major neonatal sequelae, including cerebral palsy, bronchopulmonary dysplasia (BPD), and respiratory distress syndrome (RDS).

Assessment of office-based care of sexually transmitted diseases and vaginitis and antibiotic decision-making by obstetrician-gynecologists.

OBJECTIVE: Survey office-based obstetric-gynecologic practitioners regarding their knowledge of infectious disease care and antibiotic use. METHODS: A survey questionnaire of multiple-choice questions was mailed to Fellows of the American College of Obstetricians and Gynecologists about clinical entities for which recommendations have undergone recent changes or about which there was a lack of consensus in a prior similar survey (Gibbs RS, McGregor JA, Mead PB, et al.: Obstet Gynecol 83:631-636, 1994). RESULTS: Respondents indicated that oral metronidazole was their most frequent choice to treat bacterial vaginosis. Ampicillin (57%) was used more often than penicillin (39%) for intrapartum group B streptococcus prophylaxis. Azithromycin was preferred (61%) over erythromycin-base (38%) for chlamydia treatment during pregnancy. There were several modes of practice that deviated from accepted care: 27% and 29% did not screen for chlamydia and gonorrhea, respectively, in pregnancy; 17% used cultures for Gardnerella vaginalis to diagnose bacterial vaginosis; 25% considered quinolones to be safe in pregnancy; 93% felt metronidazole should never be used in pregnancy; and the majority (66%) would send a patient treated successfully for pelvic cellulitis home with an oral antibiotic. CONCLUSION: Respondents infectious disease knowledge and practices in obstetrics and gynecology is appropriate in treating sexually transmitted diseases, bacterial vaginosis, and group B streptococcus. Numerous deficiencies still exist in screening for sexually transmitted diseases in pregnancy and diagnosing bacterial vaginosis, as well as in the choice of antibiotics to use or avoid for certain infections.

Comparison of umbilical artery pH and 5-minute Apgar score in the low-birth-weight and very-low-birth-weight infant

The division between normal and low Apgar scores is based largely on data obtained from term newborns and may not apply to the premature infant. Umbilical artery pH has been suggested as a better indicator of intrapartum asphyxia. We examined the charts of 558 infants with birth weights less than or equal to 2500 gm with respect to umbilical artery pH, 5-minute Apgar scores, and birth weight percentiles. A positive correlation between birth weight and 5-minute Apgar score was noted. No such relationship existed between birth weight and umbilical artery pH. Within birth weight groups, small-for-gestational-age infants have higher Apgar scores and lower umbilical artery pH values than their appropriate-for-gestational age counterparts.

A randomized trial of conjugated group B streptococcal type Ia vaccine in a rabbit model of ascending infection.

OBJECTIVEnMaternal vaccination may become a central strategy in the prevention of early-onset group B Streptococcal sepsis. Unlike earlier group B streptococcal polysaccharide vaccines that were poorly immunogenic, newer vaccines conjugated to tetanus toxoid have been developed and have improved immunogenicity. We sought to evaluate a conjugated vaccine using our rabbit model of ascending infection.nnnSTUDY DESIGNnRabbit does were randomized to receive either conjugated group B streptococcal type Ia (Ia-tetanus toxoid) or conjugated group B streptococcal type III (III-tetanus toxoid) vaccine. Does were vaccinated 7 days before conception and 7 and 21 days after conception. On days 28 to 30 of a 30-day gestation, does were inoculated intracervically with 10(6) colony-forming units of type Ia group B Streptococcus. Labor was induced if does were undelivered after 72 hours. Does were observed up to 7 days after inoculation. Offspring were observed up to 4 days. We obtained maternal cultures from the uterus, peritoneum, and blood and offspring cultures from the mouth, anus, and blood. Antibody levels were also determined.nnnRESULTSnOffspring survival was significantly improved in the group receiving Ia-tetanus toxoid (P =.047). Outcomes such as maternal sepsis and severe illness, although not reaching statistical significance, showed a trend toward improved outcomes in the Ia-tetanus toxoid group.nnnCONCLUSIONSnThis is the first study to evaluate the conjugated group B streptococcal vaccine by using any model of ascending infection. The Ia-tetanus toxoid vaccine led to improved survival and was immunogenic but fell short of its expected efficacy in preventing ascending group B streptococcal disease under these experimental conditions.

Oral Quinolone in the Treatment of Experimental Polymicrobial Puerperal Infection in Rabbits

Objective To evaluate the efficacy of oral levofloxacin in the treatment of experimental polymicrobial puerperal infection in the rabbit. Methods Timed pregnant rabbits were anesthetized on day 29 or 30 of a 31-day gestation and 105−6 colony-forming units each of Escherichia coli, group B streptococcus, and Staphylococcus saccharolyticus were inoculated endoscopically in the cervices. Labor was induced with intramuscular oxytocin 16 hours later if it had not occurred spontaneously. The animals then were observed every 3 hours for fever; when a temperature of 104F was reached, treatment was begun. Animals were assigned randomly in a blinded, placebo-controlled manner to received oral levofloxacin (10 mg/kg/day) or placebo and were treated twice daily for 4–5 days. The animals were killed and necropsy was performed 4–6 hours after the last dose. Specimens for culture were taken from uterine horns, peritoneum, and blood. Levofloxacin concentrations were determined from blood samples at necropsy. Clinical cure of fever, eradication of microbes, and presence of uterine abscesses at necropsy were assessed. Results Compared with placebo-treated rabbits, levofloxacin-treated animals had a significantly greater number of clinical cures (nine of 11 versus four of 12, P = .027) and significantly more eradication of E coli (ten of 11 versus five of 12, P = .022). Four uterine abscesses were seen in 12 placebo-tested animals, compared with none of 11 levofloxacin-tested animals (P = .093). There was no difference in eradication of group B streptococcus between the two groups. No blood cultures were positive for organisms in any animal. Levofloxacin was detected in all treated animals, but at low levels (less than 1 mg/mL). Conclusion Treatment of experimental puerperal infection with oral levofloxacin in rabbits resulted in significantly more clinical cures and eradication of E coli compared with treatment with placebo.

Tips of the slongue: The enduring legacy of W.A. Spooner

Slips of the tongue are common and often amusing phonic errors. Although surely not the first speaker to make such transpositions, W.A. Spooner (1844-1930) was well known for them and was the source of the eponym, Spoonerism. Several of his noted slips are presented along with a whimsical obstetric presentation.

Randomized, Placebo-Controlled Trial of Transplacental Antibiotic Prophylaxis of Neonatal Group B Streptococcal Colonization and Bacteremia in Rabbits

Objective: We evaluated the effect of maternal administration of ampicillin/sulbactam on colonization and bacteremia in newborn rabbits after intracervical inoculation of mothers with group B streptococci (GBS). Methods: New Zealand white rabbits on day 30 of a 31-day gestation were inoculated intracervically with 104−105 colony forming units (cfu) GBS. Two hours after inoculation mothers received ampicillin/sulbactam (50 mg/kg) or saline (control) intramuscularly as a single dose, in a randomized double-blinded manner. We induced labor 4 h later with intramuscular oxytocin. At delivery, cultures for GBS were taken from neonatal oropharynx. Thereafter, cultures were taken from neonatal oropharynx and anorectum daily and from neonatal heart at death or after 96 h. Sample size analysis showed a need for 17 pups in each group. Results: In the control group, induction failed in one animal that was excluded from analysis. At birth, 0 of 39 pups of treated does had positive oropharyngeal cultures compared to 26 of 27 (96%) pups of saline-treated does (P < 0.0001). Pups treated with antibiotic in utero were also significantly less likely to have positive oropharyngeal cultures at 24, 48, and 72 h after birth compared to controls (24 h, 0% vs. 100%, P < 0.0001; 48 h, 8% vs. 100%, P < 0.0001; 72 h, 16% vs. 100%, P < 0.0001). Treated pups were significantly less likely to have positive anorectal cultures at 24, 48, and 72 h after birth compared to control animals (24 h, 0% vs. 100%, P < 0.0001; 48 h, 0% vs. 95%, P < 0.0001; 72 h, 0% vs. 92%, P < 0.0001). Treated pups were significantly less likely to have positive heart cultures at 72 h after birth compared to controls (11% vs. 92%, P < 0.0002). Cumulative neonatal survival was higher in treated pups compared to controls at 72 and 96 h after birth (72 h, 32% vs. 0%, P = 0.0003; 96 h, 26% vs. 0%, P = 0.015). Conclusions: Single dose transplacental prophylaxis given 4 h before delivery resulted in decreased neonatal GBS colonization and bacteremia and improved neonatal survival in rabbits.