The interrelationship of complement-activation fragments and angiogenesis-related factors in early pregnancy and their association with pre-eclampsia

OBJECTIVE

To determine the interrelationships during early pregnancy of complement-activation fragments Bb, C3a and sC5b-9, and angiogenesis-related factors placental growth factor (PiGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), and their associations with pre-eclampsia.

DESIGN

Prospective cohort study.

SETTING

Denver complement study (June 2005-June 2008).

POPULATION

A total of 668 pregnant women with singleton gestations, recruited between 10 and 15 weeks of gestation.

METHODS

Using univariable and multivariable logistic regression analysis, concentrations of complement-activation fragments and angiogenesis-related factors were compared between 10 and 15 weeks of gestation in women who subsequently did or did not develop pre-eclampsia. Interrelationships between these variables were tested using the non-parametric Spearman rank correlation coefficient.

MAIN OUTCOME MEASURE

Pre-eclampsia. The association of complement-activation fragments and angiogenesis-related factors with obesity was also examined.

RESULTS

The mean (+/-SD) levels of complement Bb in early pregnancy among women who did and did not develop pre-eclampsia were 0.84 (+/-0.26) microg/ml and 0.69 (+/-0.2) microg/ml, respectively (P = 0.001). Concentrations of PiGF were significantly (P = 0.01) lower (31 +/- 12 pg/ml) in early pregnancy in the pre-eclamptic group of women, as compared with the normotensive group (39 +/- 32 pg/ml). The adjusted odds ratio (AOR) of Bb and PiGF were 2.1 (CI = 1.4-3.1, P < 0.0003) and 0.2 (CI = 0.07-0.7, P = 0.01), respectively. There was no significant difference in the levels of C3a, sC5b-9, sFlt-1 and sEng in early pregnancy among women who developed pre-eclampsia, compared with women who remained normotensive during pregnancy. Higher levels of Bb (P = 0.0001) and C3a (P = 0.03), and lower levels of sFlt-1 (P = 0.0002) and sEng (P = 0.0001) were found among women with obesity, compared with non-obese controls. No meaningful relationships were found between the complement-activation fragments and the angiogenesis-related factors.

CONCLUSIONS

In this cohort during early pregnancy, increased concentrations of complement-activation factor Bb and lower concentrations of PiGF were associated with the development of pre-eclampsia later in pregnancy.

The relationship between infections and adverse pregnancy outcomes: an overview

Preterm birth with its subsequent morbidity and mortality is the leading perinatal problem in the United States. Infants born before the thirty-seventh week of gestation account for approximately 6% to 9% of all births, but 70% of all perinatal deaths and half of all long-term neurologic morbidity. Current approaches focus on symptomatic treatment. Despite widespread use of drugs to arrest preterm labor (tocolytics), there has been no decrease in low birth weight or preterm infants in the last 20 years. It is likely that therapy directed at preventing or treating underlying causes would be more successful. Evidence from many sources links preterm birth to symptomatic infections, for example, of the urinary or respiratory tracts. In the last decade, great interest has been generated to support the hypothesis that subclinical infection is an important cause of preterm labor. Evidence to support this may be categorized as follows: histological chorioamnionitis is increased in preterm births; clinical infection is increased after preterm birth; there is significant association of some lower genital tract organisms and infections with preterm birth or preterm premature rupture of the membranes; there are positive cultures of amniotic fluid or membranes from some patients with preterm labor and preterm birth; there are markers of infections in preterm birth; bacteria or their products induce preterm birth in animal models; and some antibiotic trials have shown a lower rate of preterm birth or have deferred preterm birth. In the last 5 years, additional exciting information has suggested that not only is subclinical infection responsible for preterm birth but also many serious neonatal sequelae including periventricular leukomalacia, cerebral palsy, respiratory distress, and even bronchopulmonary dysplasia and necrotizing enterocolitis. In sum, a large body of clinical and laboratory information suggests that subclinical infection is a major cause of preterm birth, especially those occurring before 30 weeks. This concept holds promise that new approaches can be developed to prevent prematurity.

A Randomized Controlled Trial of Metronidazole Vaginal Cream in the Treatment of Papanicolaou Smears Showing Atypical Squamous Cells of Undetermined Significance (ASCUS)

OBJECTIVE

To compare topical metronidazole gel vs. placebo to assess resolution to normal in subsequent Pap smears of patients with ASCUS.

MATERIALS AND METHODS

Patients with ASCUS pap smears were randomized to metronidazole or placebo. Resolution of ASCUS vs. persistence, or progression, was the endpoint. A subanalysis stratified patients for bacterial vaginosis (BV) to determine if this population responded differently. Discrete variables were compared using chi-square analysis.

RESULTS

Forty-nine patients received metronidazole and 52 received placebo. The rate of resolution in the placebo group were 60%, and 67% in the metronidazole group. With BV, the rate of resolution in the placebo group was 67%, and 70% in the metronidazole group. These were not significantly different.

CONCLUSIONS

Treatment of ASCUS Pap smears using topical metronidazole did not demonstrate a significant increase in the rate of resolution in subsequent Pap smears in the overall group nor in a subgroup with BV.

Impact of infectious diseases on women's health: 1776-2026

In this commentary, the author reviews the impact of infectious diseases on women's health, beginning with the late 18th century when clinically recognized infections took the heaviest toll on women. The review continues through the 19th and 20th centuries when public health measures and the advent of antibiotic agents led to apparent control of infection, and ends with a forecast for the next 25 years. Foreboding considerations for the future include spread of human immune deficiency virus infection and other sexually transmitted diseases and the development of new infections, antibiotic-resistant bacteria, and the recognition of infection as a cause of many obstetric-gynecologic and chronic disorders. Obstetricians and gynecologists can contribute to the solution of these problems individually and collectively.

A randomized controlled trial of interleukin-1 receptor antagonist in a rabbit model of ascending infection in pregnancy

OBJECTIVE

To determine whether treatment with interleukin-1 receptor antagonist (IL1-ra) would affect amniotic fluid concentrations of tumor necrosis factor alpha (TNF-alpha) and prostaglandins or clinical or microbiological outcomes in a model of ascending bacterial infection in pregnancy.

METHODS

Timed pregnant New Zealand white rabbits at 70% of gestation underwent endoscopic inoculation of the cervices with 10(6) - 10(7) cfu Escherichia coli. Animals were randomly assigned in a blinded manner to a 5-h intravenous infusion of human IL1-ra (10 mg/kg) or placebo beginning 1-2 h after inoculation. Blood was drawn from the does for assay of serum IL1-ra concentration before inoculation, at mid-infusion, after the infusion ended and at necropsy. At necropsy, temperature and cultures were taken, and aspirated amniotic fluid was pooled for assays of TNF-aalpha, prostaglandin E2 (PGE2) and ILI-ra.

RESULTS

Serum IL1-ra concentrations rose to a mean of 2 microg/ml at mid-infusion and fell markedly after the infusion to concentrations barely detectable at necropsy. Between the two groups, there were no significant differences in the rates of fever or positive cultures or in amniotic fluid concentrations of PGE2 or TNF-alpha. One unique finding was the demonstration that administration of human IL1-ra to the does resulted in measurable concentrations of human IL1-ra in the amniotic fluid.

CONCLUSIONS

Treatment with an intravenous infusion of human IL1-ra after cervical inoculation with E. coli did not affect clinical or microbiological outcomes or amniotic fluid concentrations of TNF-alpha or PGE2. This experiment providesthefirstdemonstration of passage of human IL1-ra from the maternal bloodstream to the amniotic fluid.

Histologic inflammation in the maternal and fetal compartments in a rabbit model of acute intra-amniotic infection

OBJECTIVE

This study was undertaken to determine the course of acute inflammation in the maternal and fetal compartments during experimentally induced ascending intra-amniotic infection.

STUDY DESIGN

Forty pregnant rabbits at 70% gestation were inoculated endocervically with 10(5) colony-forming units of Escherichia coli. Does were killed at 0, 4, 8, 16, 24, and 30 hours after inoculation. At necropsy, blood, peritoneal fluid, amniotic fluid, and uterine tissue were cultured. Fetal brain, lung, heart, gut, and kidney were collected for histologic examination. Necrosis, infiltrates, congestion, and edema were each assessed semiquantitatively, and mean composite histologic-inflammation scores were compared with analysis of variance. Inflammation, mitotic activity, and apoptosis were evaluated in the fetal brain, and groups were compared with analysis of variance.

RESULTS

Twenty-six animals were evaluated after 14 were excluded (lack of fever or positive culture results). A significant increase in histologic inflammation score was seen in the uterus (P<.001), placenta(P = .011), and fetal lung (P = .001) but not in other fetal tissues. These changes were seen earlier in the uterus and placenta and later in the fetal lung. Mitotic activity in the fetal brain decreased significantly by 8 hours after cervical inoculation. There was no inflammation in the fetal brain, and apoptosis in the fetal brain did not increase with time.

CONCLUSIONS

Histologic inflammation occurs early in both the uterus and the placenta and later in the fetal lung in the rabbit model of acute intra-amniotic infection. This contrasts with the previously reported chronic model of intra-amniotic infection in the rabbit.

Acute intrauterine infection results in an imbalance between pro- and anti-inflammatory cytokines in the pregnant rabbit

PROBLEM

Intrauterine infection results in an increase in cytokines. This study compared the time courses for the pro- and anti-inflammatory cytokine responses in 33 pregnant rabbits at 70% gestation. Pro-inflammatory markers were activated nuclear factor-kappa B (NF-kappaB) in placenta and tumor necrosis factor-alpha (TNF-alpha) in amniotic fluid. These were compared to the anti-inflammatory cytokine, interleukin-1 receptor antagonist (IL-1ra), in placenta and uterus.

METHOD OF STUDY

Does were endoscopically inoculated with Escherichia coli through their cervices and sacrificed at six intervals between 0 and 30 hr post-inoculation.

RESULTS

Activated NF-kappaB, determined by electromobility gel shift assay, increased significantly 16 hr after bacterial inoculation (P < or = 0.05). This was directly mirrored by TNF-alpha concentrations, determined by bioassay, in the amniotic fluid. However, IL-1ra levels, determined by enzyme-linked immunosorbent assay, did not increase in response to infection.

CONCLUSIONS

Intrauterine infection results in an imbalance between pro- and anti-inflammatory cytokines that may potentiate infection-induced preterm delivery.

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

OBJECTIVE

Maternal 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.

STUDY DESIGN

Rabbit 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.

RESULTS

Offspring 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.

CONCLUSIONS

This 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 106 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 microg/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.

Epidemiology and outcomes associated with moderate to heavy Candida colonization during pregnancy. Vaginal Infections and Prematurity Study Group

OBJECTIVE

Our purpose was to determine the risk factors, physical findings, microflora, and pregnancy outcome among pregnant women with moderate to heavy vaginal growth of Candida albicans and other Candida species.

STUDY DESIGN

A multicenter cohort of 13,914 women were enrolled between 23 and 26 weeks' gestation. Women completed a questionnaire, underwent a physical examination, and had genital specimens taken for culture. A subset of 1459 women were reexamined during the third trimester. Pregnancy outcomes were recorded at delivery.

RESULTS

The prevalence of moderate to heavy Candida colonization at midgestation was 10%. Colonized women, 83% of whom carried C. albicans, were more likely to be black or Hispanic, unmarried, a previous oral contraceptive user, and to manifest clinical signs indicative of Candida carriage. Candida colonization was positively associated with Trichomonas vaginalis, group B streptococci, and aerobic Lactobacillus and was not associated with adverse pregnancy outcome.

CONCLUSION

These results suggest that Candida colonization is not associated with low birth weight or preterm delivery.

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.

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.

Use of antibiotics to prevent preterm birth

Our purpose is to review recent data and provide a clinical opinion on the use of antibiotics to prevent preterm birth or related maternal-neonatal complications. A literature review and a synthesis of opinion are provided. During prenatal care, standard practices should be applied regarding Neisseria gonorrhoeae, Chlamydia trachomatis, and bacteriuria. In addition, screen for and treat bacterial vaginosis in patients at high risk for preterm birth but do not treat Ureaplasma urealyticum or group B streptococci genital colonization. With preterm labor and intact membranes, standard practices should be applied regarding group B streptococci prophylaxis. Do not give antibiotics routinely to prolong pregnancy, but in patients with bacterial vaginosis and Trichomonas vaginalis specific treatment should be given. With preterm premature rupture of membranes, standard practices should be applied regarding group B streptococci prophylaxis, but additional antibiotics should also be given to prolong pregnancies at 24 to 32 weeks' gestation. Reported adverse effects have been few to date. However, increased diligence is needed for resistant organisms. In selected clinical settings antibiotic therapy is now indicated to prolong pregnancy and prevent maternal-neonatal complications associated with preterm birth.

Trichomonas vaginalis associated with low birth weight and preterm delivery. The Vaginal Infections and Prematurity Study Group

BACKGROUND

Several studies have suggested that pregnant women infected with Trichomonas vaginalis may be at increased risk of an adverse outcome.

GOAL

To evaluate prospectively the association between T. vaginalis and risk of adverse pregnancy outcome in a large cohort of ethnically diverse women.

STUDY DESIGN

At University-affiliated hospitals and antepartum clinics in five United States cities, 13,816 women (5,241 black, 4,226 Hispanic, and 4,349 white women) were enrolled at mid-gestation, tested for T. vaginalis by culture, and followed up until delivery.

RESULTS

The prevalence of T. vaginalis infection at enrollment was 12.6%. Race-specific prevalence rates were 22.8% for black, 6.6% for Hispanic, and 6.1% for white women. After multivariate analysis, vaginal infection with T. vaginalis at mid-gestation was significantly associated with low birth weight (odds ratio 1.3; 95% confidence interval 1.1 to 1.5), preterm delivery (odds ratio 1.3; 95% confidence interval 1.1 to 1.4), and preterm delivery of a low birth weight infant (odds ratio 1.4; 95% confidence interval 1.1 to 1.6). The attributable risk of T. vaginalis infection associated with low birth weight weight in blacks was 11% compared with 1.6% in Hispanics and 1.5% in whites.

CONCLUSIONS

After considering other recognized risk factors including co-infections, pregnant women infected with T. vaginalis at mid-gestation were statistically significantly more likely to have a low birth weight infant, to deliver preterm, and to have a preterm low birth weight infant. Compared with whites and Hispanics, T. vaginalis infection accounts for a disproportionately larger share of the low birth weight rate in blacks.

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.

Intra-amniotic infection and premature rupture of the membranes

The outcome of fetuses and newborn infants often is linked to maternal complications. IAI and PROM are key risk factors for neonatal sepsis.

Ascending group B streptococcal genital infection in the rabbit model

OBJECTIVE

We investigated in a pregnant rabbit model the effects of intravaginal inoculation of type la group B streptococci and antibiotic intervention.

STUDY DESIGN

We inoculated 10(4) to 10(6) cfu of type la group B streptococci into the upper vagina hysteroscopically at day 21 to 27 of a 31-day gestation. Initially we studied the natural history in 23 animals and then allocated the next 31 animals to receive either no therapy or ampicillin-sulbactam intramuscularly beginning immediately after inoculation. Outcomes were delivery, fever, positive cultures for group B streptococci, any live fetuses, and maternal death.

RESULTS

Without antibiotic treatment upper vaginal inoculation led to frequent complications, namely, fever in 44% (15/34), delivery in 41% (14/34), positive endometrial cultures in 47% (15/32), and positive blood cultures in 26% (7/27). Live fetuses were present in only 53% (18/34). Animals treated with antibiotics were significantly less likely to have fever (p < 0.01), positive endometrial cultures (p < 0.01), or positive blood cultures (p = 0.03) and were more likely to have a live fetus (p = 0.04) than untreated animals were.

CONCLUSION

Upper vaginal inoculation with type la group B streptococci in the rabbit led to an ascending infection of the upper genital tract, causing serious adverse outcomes in 40% with bacteremia in 26%. Early antibiotic intervention significantly improved outcomes. The susceptibility of the rabbit to ascending perinatal group B streptococci infection makes it an appealing model for further work pertinent to human disease.

The effect of timing of single-dose transplacental ampicillin-sulbactam therapy for prevention of neonatal group B streptococcal colonization and bacteremia in a rabbit model

OBJECTIVE

Our purpose was to evaluate the effect of maternal administration of ampicillin-sulbactam on group B streptococcal colonization and bacteremia in newborn rabbits.

STUDY DESIGN

Before induction of labor, timed pregnant New Zealand White rabbits on day 29 of a 31-day gestation received no therapy or ampicillin-sulbactam 50 mg/kg intramuscularly as a single dose 2 to 8 hours before delivery. Labor was induced with oxytocin. After delivery, the oropharynx of each pup was inoculated with 10(9) cfu of type la group B Streptococcus. Cultures of each pup were taken from the oropharynx and anorectum daily and from the heart at death or after 96 hours. Ampicillin-sulbactam concentrations were determined at delivery in both mothers and pups.

RESULTS

Thirteen animals were assigned to no therapy and 14 animals to ampicillin-sulbactam. Untreated pups had 100% oropharyngeal colonization at 24 hours. Pups treated with antibiotic were significantly less likely to have positive oropharyngeal cultures at 24 and 48 hours after birth than did untreated pups (24 hours 47% vs 100%, p < 0.0001; 48 hours 68% vs 91%, p = 0.0006). For anorectal cultures treated pups were significantly less likely to have positive culture results. Heart cultures were also less likely to have positive results for treated animals at 48 and 72 hours than for untreated animals (48 hours 30% vs 96%, p = 0.0001; 72 hours 31% vs 71%, p = 0.03). Treated pups had higher rates of survival at 48 hours (89% vs 62%, p < 0.0001). When neonatal oropharyngeal colonization at 24 hours after birth was compared with length of time from maternal antibiotic injection to delivery, there was a significant polynomial relationship (r = 0.78, p < 0.05). Ampicillin-sulbactam serum concentrations were highest 3 to 5 hours after injection. An inverse relationship existed between the rate of neonatal oropharyngeal colonization with group B streptococci at 24 hours after birth and neonatal ampicillin serum concentrations near birth (r = 0.733).

CONCLUSION

Transplacental treatment with a single intramuscular dose of ampicillin-sulbactam significantly decreased neonatal colonization and bacteremia after oral inoculation with type la group B Streptococcus. An effect of ampicillin-sulbactam was evident as early as 2 hours but maximal 3 to 5 hours after injection.

Colonization with group B streptococci in pregnancy and adverse outcome. VIP Study Group

OBJECTIVE

Our purpose was to study the association of cervicovaginal colonization with group B streptococci with pregnancy and neonatal outcome.

STUDY DESIGN

A prospective study was conducted at seven medical centers between 1984 and 1989. Genital tract cultures were obtained at 23 to 26 weeks' gestation and at delivery. Prematurity and neonatal sepsis rates were compared between group B streptococci positive and negative women.

RESULTS

Group B streptococci was recovered from 2877 (21%) of 13,646 women at enrollment. Heavy colonization was associated with a significant risk of delivering a preterm infant who had a low birth weight (odds ratio = 1.5, 95% confidence interval 1.1 to 1.9). Heavily colonized women given antibiotics effective against group B streptococci had little increased risk of a preterm, low-birth-weight birth. Women with light colonization were at the same risk of adverse outcome as the uncolonized women. Neonatal group B streptococci sepsis occurred in 2.6 of 1000 live births in women with and 1.6 of 1000 live births in women without group B streptococci at 23 to 26 weeks' gestation (p = 0.11). However, sepsis occurred in 16 of 1000 live births to women with and 0.4 of 1000 live births to women without group B streptococci at delivery (p < 0.001).

CONCLUSIONS

Heavy group B streptococci colonization of 23 to 26 weeks' gestation was associated with an increased risk of delivering a preterm, low-birth-weight infant. Cervicovaginal colonization with group B streptococci at 23 to 26 weeks' gestation was not a reliable predictor of neonatal group B streptococci sepsis. Colonization at delivery was associated with sepsis.

Association between bacterial vaginosis and preterm delivery of a low-birth-weight infant. The Vaginal Infections and Prematurity Study Group

BACKGROUND

Bacterial vaginosis is believed to be a risk factor for preterm delivery. We undertook a study of the association between bacterial vaginosis and the preterm delivery of infants with low birth weight after accounting for other known risk factors.

METHODS

In this cohort study, we enrolled 10,397 pregnant women from seven medical centers who had no known medical risk factors for preterm delivery. At 23 to 26 weeks' gestation, bacterial vaginosis was determined to be present or absent on the basis of the vaginal pH and the results of Gram's staining. The principal outcome variable was the delivery at less than 37 weeks' gestation of an infant with a birth weight below 2500 g.

RESULTS

Bacterial vaginosis was detected in 16 percent of the 10,397 women. The women with bacterial vaginosis were more likely to be unmarried, to be black, to have low incomes, and to have previously delivered low-birth-weight infants. In a multivariate analysis, the presence of bacterial vaginosis was related to preterm delivery of a low-birth-weight infant (odds ratio, 1.4; 95 percent confidence interval, 1.1 to 1.8). Other risk factors that were significantly associated with such a delivery in this population were the previous delivery of a low-birth-weight infant (odds ratio, 6.2; 95 percent confidence interval, 4.6 to 8.4), the loss of an earlier pregnancy (odds ratio, 1.7; 1.3 to 2.2), primigravidity (odds ratio, 1.6; 1.1 to 1.9), smoking (odds ratio, 1.4; 1.1 to 1.7); and black race (odds ratio, 1.4; 1.1 to 1.7). Among women with bacterial vaginosis, the highest risk of preterm delivery of a low-birth-weight infant was found among those with both vaginal bacteroides and Mycoplasma hominis (odds ratio, 2.1; 95 percent confidence interval, 1.5 to 3.0).

CONCLUSIONS

Bacterial vaginosis was associated with the preterm delivery of low-birth-weight infants independently of other recognized risk factors.

The genital flora of women with intraamniotic infection. Vaginal Infection and Prematurity Study Group

The relationship of genital flora assessed at the end of the second trimester of pregnancy and intraamniotic infection diagnosed by clinical signs and symptoms during labor was evaluated. Women were enrolled at 23-26 weeks of gestation and followed through delivery in the multi-center Vaginal Infections and Prematurity Study (1984-1989). Among the cohort of 11,989 followed through delivery, 286 (2.4%) developed intraamniotic infection. The recovery of Gardnerella vaginalis (relative risk [RR] = 1.8; 95% confidence interval [CI] = 1.4-2.4), heavy growth of Bacteroides species (RR = 1.5; 95% CI = 1.1-2.1), and isolation of Mycoplasma hominis (RR = 1.7; 95% CI = 1.3-2.1) from the vagina at the end of the second trimester of pregnancy were associated with an increased risk of intraamniotic infection. Bacterial vaginosis was also associated with intraamniotic infection (RR = 1.5; 95% CI = 1.1-2.2). These findings extend prior studies by showing that prenatal cultures for microorganisms associated with bacterial vaginosis predicted an increased risk of intraamniotic infection.

Women's reasons for not seeking prenatal care: racial and ethnic factors

Our objective was to determine if there were differences in the reasons for not seeking early prenatal care among low-income black, Hispanic, and white women who had four or fewer prenatal care visits or care only in the third trimester, and who gave birth at Denver General Hospital in Colorado. Data were gathered from 606 women (48% Hispanic, 26% black, 26% white) after delivery, using a 188-item questionnaire and abstracted medical charts. The most important reasons for not seeking early prenatal care were attitudinal (47%), financial (26%), and structural and system problems (8.5%). Financial reasons were more important to white than to black or Hispanic women, and attitudinal reasons were more important to black and Hispanic than to white women. The analysis showed that education and marital status were sometimes confounding variables. Clear differences in reasons for not seeking prenatal care were reported by women of dissimilar racial and ethnic groups in this public hospital. Cultural variations in women's views should be taken into account in developing programs intended to improve prenatal care and pregnancy outcome in Denver.

Outcome of the Vaginal Infections and Prematurity Study: results of a clinical trial of erythromycin among pregnant women colonized with group B streptococci

OBJECTIVE

Our purpose was to determine whether erythromycin treatment of pregnant women colonized with group B streptococci would reduce the occurrence of low birth weight (< 2500 gm) and preterm (< 37 completed weeks) birth.

STUDY DESIGN

In a double-blind clinical trial, 938 carriers of group B streptococci were randomized to receive erythromycin base (333 mg three times a day) or matching placebo beginning during the third trimester and before 30 weeks and continuing for 10 weeks or until 35 weeks 6 days of pregnancy.

RESULTS

Pregnancy outcomes were available for 97% of randomized women; 14% of subjects withdrew from the trial. Birth weight < 2500 gm occurred in 8.6% of the erythromycin and 6.1% of the placebo recipients (relative risk 1.4, 0.9 to 2.2, p = 0.16). Preterm delivery occurred in 11.4% of women randomized to erythromycin and in 12.3% randomized to placebo (relative risk 0.9, 95% confidence limits 0.6 to 1.3, p = 0.65). Greater benefit of erythromycin in reducing these outcomes was not observed among women reporting the best compliance.

CONCLUSIONS

In this study of pregnant women colonized with group B streptococci treatment with erythromycin was not shown to be effective at prolonging gestation or reducing low birth weight. Greater than anticipated complicating factors, including spontaneous clearance of the organism, use of nontrial antibiotics, and density of colonization, may have resulted in population sizes too small to detect a benefit of treatment. Future studies should take these factors into account in determining sample sizes.

A comparison of aztreonam and two regimens of gentamicin in a rabbit model of intra-amniotic infection and sepsis

OBJECTIVE

To compare aztreonam in a standard dose with two gentamicin doses in the early treatment of experimental intra-amniotic infection in rabbits induced by intracervical inoculation with Escherichia coli.

METHODS

Timed pregnant rabbits on day 21 (70% of gestation) were inoculated intracervically with 10(4)-10(5) colony-forming units of E coli. After inoculation, the animals were treated with one of three regimens: 1) aztreonam at 90 mg/kg/day ("standard" dose in humans), 2) gentamicin at 4.5 mg/kg/day ("standard" dose in humans), or 3) higher-dose gentamicin at 6.0 mg/kg/day, each given in three divided doses daily. Outcomes included fever, delivery, and presence of a live fetus. At necropsy, cultures were taken from endometrium, amniotic fluid, and blood. Data were analyzed by Fisher exact test because the expected cell size was fewer than five.

RESULTS

Compared with rabbits treated with aztreonam, those treated with gentamicin 4.5 mg/kg/day delivered significantly more often (P = .002), had more positive cultures (P < .001), and had significantly fewer live fetuses (P < .001). Compared with rabbits treated with gentamicin 6.0 mg/kg/day, those treated with gentamicin 4.5 mg/kg/day delivered more often (P = .003), had fewer live fetuses (P = .02), and had more positive cultures (P = .02). There were no significant differences between the aztreonam and gentamicin 6.0 mg/kg/day groups.

CONCLUSIONS

This study demonstrates in an animal model that aztreonam and gentamicin at 6.0 mg/kg/day are more effective than gentamicin at 4.5 mg/kg/day (a dose that is widely used empirically in humans) in the early treatment of experimental intra-amniotic infection in rabbits. Aztreonam was as effective as gentamicin at 6.0 mg/kg/day. In this rabbit model, in which intra-amniotic infection is accompanied by maternal sepsis, 4.5 mg/kg/day of gentamicin was not adequate for the treatment of severe maternal infection.

A clinical, histologic, and DNA study of vulvodynia and its association with human papillomavirus

OBJECTIVE

To compare the clinical and histologic characteristics of vulvodynia with or without associated human papillomavirus (HPV) DNA, as determined by polymerase chain reaction (PCR).

METHODS

We conducted a standardized chart review of patients referred for vulvodynia lasting for more than 3 months and systematically reviewed all vulvar biopsy specimens histologically. In addition, specimens were amplified by PCR followed by Southern blot hybridization to detect HPV DNA, and positive cases were typed using the Hybrid Capture system.

RESULTS

Of 55 cases, 48 were evaluable by PCR. Human papillomavirus DNA was detected in 35% (17 of 48), including 44% (four of nine) of normal cases, 25% (eight of 32) with reactive squamous atypia, 67% (four of six) with condyloma/mild dysplasia, and 100% (one of one) with moderate/severe dysplasia. Patients who were positive for HPV DNA (n = 17) were not significantly different from HPV-negative patients (n = 31) for any of 82 clinical or epidemiologic variables. When patients with normal biopsies (n = 9) were compared to those with reactive squamous atypia (n = 39), there were significant differences in only two of 82 variables (duration of symptoms and current sexual activity). Of the 17 HPV-positive cases, 13 were typeable by the Hybrid Capture system. Five (38%) were positive for low-risk HPV types, three (23%) were positive for high-risk HPV types, and five (38%) were positive for both low- and high-risk types.

CONCLUSIONS

Vulvodynia associated with HPV DNA is clinically identical to vulvodynia without HPV DNA, and vulvodynia associated with normal biopsy findings is very similar to that with reactive squamous atypia. These data suggest that HPV does not cause vulvodynia.

Is penicillin G a better choice than ampicillin for prophylaxis of neonatal group B streptococcal infections?

A review of the pharmacokinetics and the narrow spectrum of action of penicillin G favors this antibiotic over ampicillin for the prophylaxis of early neonatal group B streptococcal (GBS) disease. Penicillin G provides good placental transfer and fetal and neonatal tissue levels. Group B streptococcal disease has a narrower range of sensitivities to penicillin G than to ampicillin, and the potential for selecting more resistant organisms may be greater with the broader spectrum of ampicillin than with penicillin G.

Neonatal group B streptococcal sepsis during 2 years of a universal screening program

OBJECTIVE

To assess the feasibility and efficacy of a protocol for universal screening for group B streptococci combined with selective intrapartum prophylaxis at a teaching hospital.

METHODS

This is a descriptive study of experience with a standardized protocol in which patients were screened at 26-28 weeks with a rectal and genital culture placed directly in selective media. As risk factors, we used clinical chorioamnionitis, preterm birth, and rupture of the membranes greater than 12 hours. Participants were all women receiving prenatal care at our hospital. Major outcomes were compliance and neonatal sepsis due to group B streptococci.

RESULTS

The prevalence of rectal and genital group B streptococci was 18.5% of 3721 screened women. Of culture-positive women, 35% developed risk factors (9% chorioamnionitis, 13% preterm birth, and 13% membrane rupture greater than 12 hours at term). With strict application of criteria, the compliance rate in administering indicated prophylaxis was 80.3%. Of women receiving prophylaxis, 42% had the first dose for 4 hours or less before delivery. There were five cases of group B streptococcal neonatal sepsis, resulting from either protocol violations, protocol failures, or both. Compared to the historic rate of group B streptococcal sepsis of 1.5 per 1000 births at our hospital, the rate in these 2 years was 1.0 per 1000 (1.6 per 1000 in the first year and 0.5 per 1000 in the second).

CONCLUSIONS

It is feasible to conduct such a protocol, but compliance is only moderately good because the algorithm is complex. The protocol is not foolproof in preventing neonatal group B streptococcal sepsis, as there are protocol failures and violations.

Randomized comparison of ampicillin-sulbactam to cefoxitin and doxycycline or clindamycin and gentamicin in the treatment of pelvic inflammatory disease or endometritis

OBJECTIVE

To evaluate the efficacy and safety of ampicillin-sulbactam (3 g every 6 hours) in patients with pelvic inflammatory disease or postpartum endometritis using a randomized, comparative, multicenter study of parallel design.

METHODS

Eligible patients with pelvic inflammatory disease were randomized to receive either ampicillin-sulbactam or cefoxitin (2 g every 6 hours) plus doxycycline (100 mg every 12 hours). Those with endometritis were randomized to ampicillin-sulbactam or clindamycin (900 mg every 8 hours) plus gentamicin (1.5 mg/kg every 8 hours). In the ampicillin-sulbactam group, chlamydia-positive patients also received oral doxycycline.

RESULTS

For pelvic inflammatory disease, the clinical response rates (cure or improvement) were 85.5% (47 of 55) and 89.6% (43 of 48) in the ampicillin-sulbactam and cefoxitin and doxycycline groups, respectively (chi 2 = 0.10, P = .76). For endometritis, the clinical response rates were 88.7% (141 of 159) and 90.8% (139 of 153) in the ampicillin-sulbactam and clindamycin and gentamicin groups, respectively (chi 2 = 0.15, P = .70). The percentages of patients with pelvic inflammatory disease who had adverse experiences were not significantly different in the cefoxitin and doxycycline group (47% [29 of 62]) than in those receiving ampicillin-sulbactam (33% [22 of 66]) (P = .12). These adverse effects were mostly mild or moderate. In the endometritis subjects, the incidence of adverse experiences in the ampicillin-sulbactam group (11% [20 of 179]) was comparable to that during treatment with clindamycin and gentamicin (12% [22 of 180]). These adverse experiences were also mostly mild to moderate.

CONCLUSION

Ampicillin-sulbactam is as effective and well tolerated as combination regimens using cefoxitin plus doxycycline and clindamycin plus-gentamicin for the treatment of pelvic inflammatory disease or endometritis, respectively.

A survey of practices in infectious diseases by obstetrician-gynecologists

OBJECTIVE

To survey current practices among obstetricians and gynecologists concerning a wide range of infectious diseases to guide future efforts in continuing medical education.

METHODS

A survey questionnaire of multiple-choice questions was mailed to 2500 physicians, under age 65, randomly selected from the American Medical Association specialty list of obstetrician-gynecologists. The first 500 returns constituted the data set and were analyzed by computer.

RESULTS

We found many clinical areas in which practice patterns were deemed appropriate, including antibiotic selection, universal screening for hepatitis B, and follow-up of urinary tract infection in pregnancy. In other areas, marked by controversy among "experts," practice patterns varied widely. These areas included management of premature rupture of the membranes and premature labor, and universal screening for group B streptococci. Areas in need of further continuing medical education efforts include management of perinatal viral infections and diagnosis and treatment of sexually transmitted diseases.

CONCLUSIONS

Although this survey indicated that practice patterns of American obstetricians and gynecologists are appropriate in many clinical areas relevant to infectious diseases, there are other clinical conditions requiring future efforts in continuing medical education.

Adverse perinatal outcome and resistant Enterobacteriaceae after antibiotic usage for premature rupture of the membranes and group B streptococcus carriage

OBJECTIVE

To report a case series of adverse perinatal outcomes associated with resistant Enterobacteriaceae after antibiotic usage for premature rupture of the membranes (PROM) and group B streptococcus.

METHODS

Maternal and neonatal records were reviewed of four cases in which adverse perinatal outcomes occurred from resistant Enterobacteriaceae after antibiotic usage for either PROM or positive group B streptococcal cultures. Information on clinical setting, antibiotic usage, maternal and neonatal complications, and maternal and neonatal cultures was noted.

RESULTS

All four cases were complicated by PROM at 25-35 weeks' gestation. Ampicillin or amoxicillin was used in several clinical settings, including therapeutically for the presence of group B streptococcus, presumptively for PROM, and prophylactically pending the results of group B streptococcal cultures. Clinical chorioamnionitis subsequently developed in all four cases, and in two cases the maternal course was prolonged and complicated by persistent fever and the need for therapy for pelvic vein thrombophlebitis. Two neonates died from fulminant clinical sepsis. A third infant, one of a twin gestation, was stillborn, presumably because of sepsis. In three cases, neonatal and placental cultures revealed Escherichia coli resistant to ampicillin; in the fourth case, Klebsiella pneumoniae was identified, with only intermediate sensitivity to ampicillin.

CONCLUSION

Resistant Enterobacteriaceae associated with adverse perinatal outcomes may result from the use of antibiotics, such as ampicillin or amoxicillin, after PROM. In deciding whether antibiotic therapy for PROM or group B streptococcal prophylaxis is appropriate, the value of purported benefits must be weighed against presumably infrequent but serious outcomes, including neonatal sepsis and death due to selection or overgrowth of resistant organisms.

A rabbit model for ascending infection in pregnancy: intervention with indomethacin and delayed ampicillin-sulbactam therapy

OBJECTIVE

In a modified pregnant rabbit model using intracervical inoculation of Escherichia coli we investigated the effects of administration of delayed antibiotics and indomethacin on outcomes.

STUDY DESIGN

We inoculated 10(5) colony-forming units of Escherichia coli or saline solution bilaterally in the cervix of New Zealand White rabbits at 70% of gestation and assigned animals to ampicillin-sulbactam therapy beginning at 0, 4, 8, 12, and 16 hours after inoculation with Escherichia coli or to no antibiotic therapy. We alternated indomethacin pretreatment in rabbits receiving no antibiotic therapy and rabbits starting ampicillin-sulbactam 4 hours after inoculation.

RESULTS

Compared with saline solution inoculated control animals, those inoculated with Escherichia coli (and given no antibiotic therapy) had significant increases in fetal loss, fever, bleeding at 24 hours, and positive cultures (100%, 92%, 76%, 98% versus 0%, respectively, all p < 0.01). In Escherichia coli-inoculated animals receiving no antibiotic therapy pretreatment with indomethacin significantly decreased bleeding and delivery within first 24 hours compared with those not treated with indomethacin (p < 0.05) but did not significantly improve fetal survival. Ampicillin-sulbactam treatment stated at 0, 4, 8, and 12 hours after inoculation resulted in improved fetal survival compared with the untreated group (100%, 56%, 50%, 50% versus 0%, respectively, all p < 0.05). Treatment initiated at 16 hours resulted in outcomes similar to Escherichia coli-inoculated animals receiving no antibiotic therapy.

CONCLUSION

Intracervical Escherichia coli inoculation produced infection in the uterus and uniform pregnancy loss. Pretreatment with indomethacin did not result in improved fetal survival. Ampicillin-sulbactam therapy, initiated as long as 12 hours after Escherichia coli inoculation, resulted in significant improvement in fetal survival compared with antibiotic therapy. We believe this model mimics ascending infection in pregnancy more closely than do previous animal models.

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.

Amniotic fluid tumor necrosis factor-alpha and interleukin-1 in a rabbit model of bacterially induced preterm pregnancy loss

OBJECTIVE

The objective of this study was to determine whether the cytokines tumor necrosis factor-alpha, interleukin-1 alpha, and interleukin-1 beta were produced in the amniotic fluid of the rabbit after intracervical inoculation with Escherichia coli.

STUDY DESIGN

Timed pregnant rabbits on day 21 (70% of gestation) were inoculated with a hysteroscope intracervically with 10(4) to 10(5) colony-forming units Escherichia coli or sterile saline solution. Escherichia coli-inoculated animals (N = 16) were put to death at 4, 8, 12, and 16 hours after inoculation. Control animals (N = 6) were put to death at similar intervals. At death, cultures were taken from endometrium, amniotic fluid, peritoneum, and blood. Amniotic fluid was collected and assayed for tumor necrosis factor bioactivity by a modified fibroblast cytotoxic assay in L929 cells, for interleukin-1 alpha, and interleukin-1 beta with a specific radioimmunoassay, and for prostaglandin E2 and prostaglandin F2 alpha by radioimmunoassay.

RESULTS

Levels of amniotic fluid tumor necrosis factor-alpha, interleukin-1 alpha, and interleukin-1 beta were elevated as early as 4 hours after inoculation in some animals and by 12 to 16 hours after inoculation in all. Levels of all three cytokines correlated significantly with time from intracervical inoculation with Escherichia coli (p < 0.05). Levels of amniotic fluid prostaglandin E2 and prostaglandin F2 alpha correlated significantly with time from intracervical inoculation with Escherichia coli (p < 0.05).

CONCLUSIONS

Levels of tumor necrosis factor-alpha, interleukin-1 alpha, interleukin-1 beta, prostaglandin E2 and prostaglandin F2 alpha are elevated in the amniotic fluid of rabbits after intracervical inoculation with Escherichia coli. Similarity exists between elevations of amniotic fluid cytokines in this model and in cases of intraamniotic infection and preterm labor unresponsive to tocolytics in humans. Modulation of cytokines may offer a strategy for improvement of outcome in this experimental model of infection-induced pregnancy loss.

A retrospective review of the efficacy and safety of prostaglandin E2 with premature rupture of the membranes at term

OBJECTIVE

The purpose of this study was to assess rates of endometritis, clinical chorioamnionitis, cesarean delivery, and neonatal sepsis from the records of patients with premature rupture of the membranes (PROM) and an unfavorable cervix treated with vaginal prostaglandin (PG) E2 in comparison with those in the literature.

METHODS

Using a computer data base at Denver General Hospital, we identified 146 women with PROM and cervical dilatation of 2 cm or less at term who were treated with PGE2 gel or suppositories. The records were reviewed to identify rates of maternal and neonatal infection and complications, as well as cesarean delivery.

RESULTS

The cesarean rate was 12%. Chorioamnionitis developed in 6.8% of the study group and endometritis in 2%. Neonatal complications were limited to two with low Apgar scores (less than 7 at 5 minutes), one with microbiologically confirmed sepsis, and two with positive urine counterimmunoelectrophoresis for group B streptococcus. The only instance of neonatal sepsis occurred in a patient with rupture of membranes longer than 24 hours.

CONCLUSIONS

The use of vaginal PGE2 suppositories for induction of labor and cervical ripening in term patients with PROM was accompanied by a high rate of vaginal delivery and a low rate of maternal and neonatal complications in a city hospital setting.

Life-threatening puerperal infection due to group A streptococci

We describe two patients with life-threatening puerperal infection due to group A beta-hemolytic streptococcus. Each patient had bacteremia, shock, and multi-organ involvement. Both cases were compatible with a recently described streptococcal toxic shock-like illness. Both women failed to improve despite vigorous medical and antibiotic therapies, and each required hysterectomy. Obstetricians should be alert to the importance of early diagnosis and treatment of this potentially lethal infection.

A review of premature birth and subclinical infection

Premature birth causes high rates of neonatal morbidity and mortality. There are multiple causes of preterm birth. This article reviews the evidence linking subclinical infection and premature birth. Although maternal genital tract colonization with specific organisms has been inconsistently associated with preterm birth and/or premature rupture of membranes, some infections have been consistently associated with preterm delivery. The association of histologic chorioamnionitis with prematurity is a consistent finding, but the mechanisms require further study. The relationship between histologic chorioamnionitis infection and the chorioamnionitis of prematurity requires additional research. A varying number of patients in "idiopathic" preterm labor have positive amniotic fluid cultures (0% to 30%), but it is not clear whether infection preceded labor or occurred as a result of labor. Evidence of subclinical infection as a cause of preterm labor is raised by finding elevated maternal serum C-reactive protein and abnormal amniotic fluid organic acid levels in some patients in preterm labor. Biochemical mechanisms for preterm labor in the setting of infection are suggested by both in vitro and in vivo studies of prostaglandins and their metabolites, endotoxin and cytokines. Some, but by no means all, antibiotic trials conducted to date have reported decreases in prematurity. These results support the hypothesis that premature birth results in part from infection caused by genital tract bacteria. In the next few years, research efforts must be prioritized to determine the role of infection and the appropriate prevention of this cause of prematurity.

Polymerase chain reaction-based genotyping for allotypic markers of immunoglobulin kappa shows allelic association of Km with kappa variable segment

Allotypic markers of immunoglobulin kappa (Km) may be determined using a novel method of amplification of the constant segment (C kappa) (IGKC) by polymerase chain reaction (PCR) followed by restriction enzyme digestion. Restriction sites in the C kappa PCR product correlate with allotypic differences among Km(1), Km(1,2), and Km(3) alleles. An AccI site in the PCR product correlates with Km(3); and presence or absence of a MaeII site correlates with the Km(1) or Km(1,2) allele, respectively. Km allelic frequencies were determined in a Caucasian population and compared to genotypic frequencies of nearby polymorphic markers. Among unrelated individuals with rheumatoid arthritis (RA) and controls, there is no evidence of allelic association between CD8A and polymorphic markers of the immunoglobulin kappa region [a V kappa (IGKV) BglII polymorphism about 24 kb centromeric to C kappa, Km allotype, and a SacI polymorphism 3.5 kb telomeric to the C kappa segment]. Similarly, there is no allelic association of the SacI C kappa polymorphism with Km or with the BglII V kappa polymorphism. However, there is evidence of allelic association of V kappa B3 and Km, specifically between the V kappa BglII 2.2-kb allele and Km(3) and also between the V kappa 3.5-kb allele and Km(1,2). Therefore, Km typing by PCR-based methods suggests the presence of allelic association between polymorphisms within the coding region of the C kappa segment and the nearest V kappa segment.

Characteristics of three vaginal flora patterns assessed by gram stain among pregnant women. Vaginal Infections and Prematurity Study Group

This study was undertaken to define the characteristics and persistence of vaginal flora in 7918 pregnant women at 23 to 26 weeks' gestation. Vaginal smears were categorized as normal (predominant lactobacilli), intermediate (reduced lactobacilli), or positive for bacterial vaginosis. The women with normal flora were least likely to have elevated vaginal pH, amine odor, milky discharge, or colonization by Gardnerella, Bacteroides, or genital mycoplasmas. Women with intermediate vaginal flora had intermediate frequencies of these clinical signs and microorganisms. Group B streptococci and yeast were associated with normal or intermediate flora, whereas Neisseria gonorrhoeae and Chlamydia trachomatis were recovered more frequently from women with intermediate flora or bacterial vaginosis. Trichomonas vaginalis was most associated with intermediate flora. At follow-up, 81% of the women with normal flora had remained normal. Of the women with intermediate flora, 32% acquired bacterial vaginosis and 30% shifted to normal flora. Only 12% of the women with bacterial vaginosis had shifted to normal flora. We conclude that there are two primary stable vaginal flora patterns (normal flora or bacterial vaginosis) and a third less distinct transitional flora pattern between these two.

The effects of pH and osmolality on bacterial growth in amniotic fluid in a laboratory model

In studying the effects of amniotic fluid on bacterial growth in a laboratory model, we noted that the pH of the fluid appeared to exert an independent effect. This study was designed to test the ability to control the growth of Escherichia coli in amniotic fluid simply by controlling two important growth conditions, pH and osmolality. The effects of pH and osmolality on growth of E. coli were systematically studied in a standard media and in amniotic fluid. Optimal ranges in standard media were pH of 5.6 to 6.6 and osmolality of 150 to 215 mOsm. When the results of growth at 24 hours were corrected for pH by analysis of covariance, the presence of amniotic fluid or phosphate had no effect. We found pH to be the only variable predictive of bacterial growth in amniotic fluid in this laboratory model.

A rabbit model for bacterially induced preterm pregnancy loss: intervention studies with ampicillin-sulbactam

We conducted experiments with a previously described rabbit model of Escherichia coli-induced preterm pregnancy loss. Does at 70% gestation were inoculated hysteroscopically with 0.2 ml of Escherichia coli (10(5) colony-forming units per milliliter) or saline solution. Animals were randomly assigned to either receive treatment with ampicillin-sulbactam (begun 1 to 2 hours before inoculation and continued for up to 7 days) or to receive no therapy. Animals were killed after delivery or after 7 days. Saline solution-inoculated animals had no pregnancy loss. Of the Escherichia coli-inoculated animals, those treated with ampicillin-sulbactam had significantly fewer deliveries, fewer positive cultures, and more live fetuses than the untreated animals (p less than or equal to 0.001). Cultures from multiple sites, amniotic fluid prostaglandin levels, and maternal progesterone levels were obtained, and the placenta, uterus, and fetal lung were histologically evaluated. In the second phase of the study, the Escherichia coli-inoculated animals were treated with ampicillin-sulbactam at one of three times: at inoculation or 2 or 4 hours after inoculation. The Escherichia coli-inoculated does treated with ampicillin-sulbactam at or before inoculation had significantly fewer deliveries, fewer positive cultures, and more live fetuses than the Escherichia coli-inoculated does in which treatment was delayed 4 hours (p less than or equal to 0.01).

Progress in pathogenesis and management of clinical intraamniotic infection

In the past decade, gratifying progress has been achieved in our understanding of clinical intraamniotic infection. With a usual incidence of 1% to 4%, clinical intraamniotic infection mainly develops as an ascending process after prolonged rupture of the membranes and labor, but other cases may be hematogenous in origin whereas still others complicate intrauterine procedures. The most common organisms isolated in amniotic fluid of cases of intraamniotic infections are anaerobes, genital mycoplasmas, group B streptococci, and Escherichia coli. The latter two are found most commonly in maternal or neonatal bacteremia complicating intraamniotic infection. Although the diagnosis remains largely a clinical one, laboratory tests have been suggested to confirm the diagnosis in women with symptoms. These include amniotic fluid Gram stain, gas-liquid chromatography, and leukocyte esterase measurement. Maternal treatment consists of antibiotic therapy and delivery. Studies to date have used a penicillin plus an aminoglycoside, with some authors advocating the addition of clindamycin after cesarean delivery. Other broad-spectrum regimens may be equally effective. Complications of clinical intraamniotic infections include an increase in cesarean section rate and in maternal and neonatal bacteremia. Poor neonatal outcomes in intraamniotic infection are more likely in the following cases: (1) when E. coli or group B streptococci are present in the amniotic fluid; (2) when the infant has a low birth weight; (3) when maternal antibiotic therapy is delayed until after delivery.