Prevention of premature birth by screening and treatment for common genital tract infections: results of a prospective controlled evaluation

Risk of premature birth in multifetal pregnancy

The risk of preterm delivery ( < 37 weeks of gestation) is approximately nine times higher in women with multifetal pregnancies than in women with singleton pregnancies. However, it is possible that the risk will vary according to gestational week. To assess the risk of premature birth within 1 week by gestational age among multifetal pregnancies and compare the estimated risk with that of singleton pregnancies, we analyzed 6 036 475 infants born in singleton pregnancies and 90 887 infants born in multifetal pregnancies in Japan ( ≥ 22 weeks) over the 5-year period 1989–1993. An estimate of the risk of birth within 1 week at gestational week n was obtained by dividing the number of infants delivered at gestational week n by the number of infants delivered at or beyond gestational week n. The risk at 22 weeks was 0.9 per 1000 fetuses for singleton pregnancies and 5.0 per 1000 for multifetal pregnancies. The risk remained relatively stable until 27 weeks of gestation, then sharply increased toward 36 weeks of gestation in both singleton and multifetal pregnancies. The odds ratio for birth within 1 week for fetuses of multifetal pregnancies compared with fetuses of singleton pregnancies was 5.9 (95% CI, 5.4–6.5) at 22 weeks of gestation, increasing gradually with increasing gestational age until 33 weeks of gestation (13.7; 95% CI, 13.1–14.2) but declining thereafter to 8.8 (95% CI, 8.6–8.9) at 36 weeks of gestation. Results of data analysis for each year of the 5-year period did not differ substantially. Twin Research (2000) 3, 2–6.

Periodontal disease and preterm birth

Preterm birth (delivery at fewer than 37 weeks’ gestation) is the most common cause of infant morbidity and mortality among nonanomalous infants in the United States. Increasing evidence has focused on associations between clinical infection, inflammation, and preterm birth. Maternal periodontal disease, which is associated with systemic inflammation, has been associated with preterm birth. Intervention trails for treatment of periodontal disease during pregnancy, however have not consistently shown a reduction in preterm birth rates. Despite the lack of reduction in preterm birth, oral health maintenance is an important part of preventive care and should be supported during pregnancy.

Diagnosis of vaginal discharge by wet mount microscopy: a simple and underrated method

Vaginal discharge is highly variable in quality and quantity among different individuals, and even in the same individual during different periods of life. Vaginal discharge is most commonly caused by infection with sexually transmitted organisms or increased colonization by different facultative pathogenic microorganisms (i.e., Gardnerella vaginalis). Noninfectious causes of vaginal discharge are quite rare (10% noninfectious as compared to 90% infectious causes). Most common in women with a vaginal infection is bacterial vaginosis (40%-50% of cases), followed by vulvovaginal candidosis (20%-25%), and then trichomoniasis (15%-20%). If infection is suspected as the primary cause, a sample of the vaginal discharge should be taken and examined microscopically. When evaluating vaginal secretions by phase-contrast wet mount microscopy, knowledge of what is normal versus abnormal is very important. Knowledge of the sensitivity and specificity of wet mount microscopy in different clinical settings is also important.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to evaluate lifetime changes in vaginal secretions, characterize the physiological and pathological appearance of vaginal discharge, assess the clinical practicality and usefulness of wet mount microscopy and use wet mount microscopy to diagnose bacterial vaginosis and other common vaginal infections.

[The role of infection in preterm birth]

Intrauterine infection could be responsible for 25% up to 40% of preterm births. This relationship was initially demonstrated using animal models, inducing their abortion by injecting bacteria or endotoxins. In human research, examination of amniocentesis fluid showed the anteriority of infection over labor induction, and the existence of a subclinical latency phase between these two phenomena. The ascending route is preponderant, and four stages can be distinguished: cervical and vaginal infection, chorio-decidual infection, intra-amniotic infection, fetal infection. The intrauterine infection is very frequent in case of early preterm birth (<30 WG). It is associated with an increase of neurological and pulmonary morbidity. Most commonly found bacterial species are mycoplasma species, but also Escherichia coli, Gardnerella vaginalis and streptococcus B. Several markers of the infection have been studied: a maternal leukocytosis>15,000/mm(3) or a C-Reactive Protein (CRP)>20mg/l, an increase of fibronectin and/or IL-6 cervical, a short cervical length especially before 32 WG, a leukocytosis of the amniotic fluid, and/or high interleukin concentrations. The main marker used for the newborn is the CRP, but other markers can also be used for an early diagnosis of an infection, especially interleukin 6.

Demographic, clinical and microbiological characteristics of maternity patients: a Canadian clinical cohort study

OBJECTIVE

To determine the demographic, clinical and microbiological characteristics of a representative Canadian obstetrical population.

DESIGN

A one-year cohort study of all maternity patients who were followed to delivery, using detailed patient questionnaires containing more than 60 demographic and clinical variables, and three microbiological evaluations during gestation - first trimester, 26 to 30 weeks, and labour and delivery. Outcome measurements included birth weight and gestational age.

SETTING

Labour and delivery suites of all office obstetrical practices affiliated with a single hospital.

POPULATION STUDIED

A consecutive sample of pregnant women in the study practices during one year were eligible for enrolment; 2237 consecutive patients were approached for consent, 2047 enrolled and 1811 completed the study through delivery.

RESULTS

The average patient was white, married and 29 years of age. Slightly more than half of the patients had postsecondary education, but 10% fell below the national poverty line for income. Frequency of factors linked to adverse pregnancy outcomes included cigarette smoking (19%), alcohol ingestion (18%), previously having had a premature infant (7%), and maternal diabetes (2%). Overall prevalence of genital microbes variously implicated in prematurity was 37% for ureaplasma, 11% for group B streptococcus and 4% for Mycoplasma hominis. Prevalence of bacterial vaginosis was 14%. The median gestational age for the cohort was 39 weeks, with 7% of infants born less than 37 weeks' gestation. Mean birth weight was 3415 g.

CONCLUSIONS

The present clinical cohort represents demographic and medical characteristics of the Canadian obstetrical population. The birth outcomes are consistent with national data. This database provides valuable information about a general obstetrical population that is managed by a universal health care system.

Treatment of abnormal vaginal flora in early pregnancy with clindamycin for the prevention of spontaneous preterm birth: a systematic review and metaanalysis

The purpose of this study was to determine whether the administration of clindamycin to women with abnormal vaginal flora at <22 weeks of gestation reduces the risk of preterm birth and late miscarriage. We conducted a systematic review and metaanalysis of randomized controlled trials of the early administration of clindamycin to women with abnormal vaginal flora at <22 weeks of gestation. Five trials that comprised 2346 women were included. Clindamycin that was administered at <22 weeks of gestation was associated with a significantly reduced risk of preterm birth at <37 weeks of gestation and late miscarriage. There were no overall differences in the risk of preterm birth at <33 weeks of gestation, low birthweight, very low birthweight, admission to neonatal intensive care unit, stillbirth, peripartum infection, and adverse effects. Clindamycin in early pregnancy in women with abnormal vaginal flora reduces the risk of spontaneous preterm birth at <37 weeks of gestation and late miscarriage. There is evidence to justify further randomized controlled trials of clindamycin for the prevention of preterm birth. However, a deeper understanding of the vaginal microbiome, mucosal immunity, and the biology of BV will be needed to inform the design of such trials.

Sexually transmitted infections and adverse pregnancy outcomes among women attending inner city public sexually transmitted diseases clinics

BACKGROUND

Studies in antenatal care clinics suggest that lower genital tract infections (LGTI) may be associated with adverse pregnancy outcomes (APO). We sought to characterize antenatal care patterns and determine whether LGTI are independently associated with preterm birth and/or low-birth weight among a high-risk public sexually transmitted diseases (STD) clinic population.

METHODS

Electronic STD clinic medical records and state birth records were matched for 730 pregnant women age 13 to 49 tested for 5 treatable LGTI (bacterial vaginosis, chlamydia, gonorrhea, early syphilis, and trichomoniasis) in a case-control analysis. Cases were women with preterm and/or low-birth weight newborns; controls were women without APO. The association between LGTI and APO was assessed using logistic regression.

RESULTS

Although pregnant women attending STD clinics reported high risk behaviors and were found to have high rates of LGTI (55%), most of these women were engaged in antenatal care (85%). Of the pregnant women, 22% experienced an APO (7% preterm birth, 4% low birth weight, and 12% preterm birth and low birth weight). In multivariate analyses, chlamydia was associated with low-birth weight (adjusted odds ratio [aOR]: 2.07, 95% confidence interval [CI]: 1.01-4.24), and gonorrhea was associated with preterm birth (aOR: 2.01, 95% CI: 1.02-3.97), particularly when diagnosed during the first trimester (aOR: 2.95, 95% CI: 1.30-6.70).

CONCLUSIONS

Our findings confirm the association of some LGTI with APO and suggest that timing of LGTI screening may affect outcomes. STD clinic visits represent a critical opportunity to target interventions aimed at improving pregnancy outcomes.

Protocol for a randomised controlled trial of treatment of asymptomatic candidiasis for the prevention of preterm birth [ACTRN12610000607077]

Background

Prevention of preterm birth remains one of the most important challenges in maternity care. We propose a randomised trial with: a simple Candida testing protocol that can be easily incorporated into usual antenatal care; a simple, well accepted, treatment intervention; and assessment of outcomes from validated, routinely-collected, computerised databases.

Methods/Design

Using a prospective, randomised, open-label, blinded-endpoint (PROBE) study design, we aim to evaluate whether treating women with asymptomatic vaginal candidiasis early in pregnancy is effective in preventing spontaneous preterm birth. Pregnant women presenting for antenatal care <20 weeks gestation with singleton pregnancies are eligible for inclusion. The intervention is a 6-day course of clotrimazole vaginal pessaries (100 mg) and the primary outcome is spontaneous preterm birth <37 weeks gestation.

The study protocol draws on the usual antenatal care schedule, has been pilot-tested and the intervention involves only a minor modification of current practice. Women who agree to participate will self-collect a vaginal swab and those who are culture positive for Candida will be randomised (central, telephone) to open-label treatment or usual care (screening result is not revealed, no treatment, routine antenatal care). Outcomes will be obtained from population databases.

A sample size of 3,208 women with Candida colonisation (1,604 per arm) is required to detect a 40% reduction in the spontaneous preterm birth rate among women with asymptomatic candidiasis from 5.0% in the control group to 3.0% in women treated with clotrimazole (significance 0.05, power 0.8). Analyses will be by intention to treat.

Discussion

For our hypothesis, a placebo-controlled trial had major disadvantages: a placebo arm would not represent current clinical practice; knowledge of vaginal colonisation with Candida may change participants' behaviour; and a placebo with an alcohol preservative may have an independent affect on vaginal flora. These disadvantages can be overcome by the PROBE study design.

This trial will provide definitive evidence on whether screening for and treating asymptomatic candidiasis in pregnancy significantly reduces the rate of spontaneous preterm birth. If it can be demonstrated that treating asymptomatic candidiasis reduces preterm births this will change current practice and would directly impact the management of every pregnant woman.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12610000607077

Treatment of asymptomatic vaginal candidiasis in pregnancy to prevent preterm birth: an open-label pilot randomized controlled trial

Background

Although the connection between ascending infection and preterm birth is undisputed, research focused on finding effective treatments has been disappointing. However evidence that eradication of Candida in pregnancy may reduce the risk of preterm birth is emerging. We conducted a pilot study to assess the feasibility of conducting a large randomized controlled trial to determine whether treatment of asymptomatic candidiasis in early pregnancy reduces the incidence of preterm birth.

Methods

We used a prospective, randomized, open-label, blinded-endpoint (PROBE) study design. Pregnant women presenting at <20 weeks gestation with singleton pregnancies self-collected a vaginal swab. Those who were asymptomatic and culture positive for Candida were randomized to 6-days of clotrimazole vaginal pessaries (100mg) or usual care (screening result is not revealed, no treatment). The primary outcomes were the rate of asymptomatic vaginal candidiasis, participation and follow-up. The proposed primary trial outcome of spontaneous preterm birth <37 weeks gestation was also assessed.

Results

Of 779 women approached, 500 (64%) participated in candidiasis screening, and 98 (19.6%) had asymptomatic vaginal candidiasis and were randomized to clotrimazole or usual care. Women were not inconvenienced by participation in the study, laboratory testing and medication dispensing were problem-free, and the follow-up rate was 99%. There was a tendency towards a reduction in spontaneous preterm birth among women with asymptomatic candidiasis who were treated with clotrimazole RR = 0.33, 95%CI 0.04-3.03.

Conclusions

A large, adequately powered, randomized trial of clotrimazole to prevent preterm birth in women with asymptomatic candidiasis is both feasible and warranted.

Trial registration

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609001052224

High sialidase levels increase preterm birth risk among women who are bacterial vaginosis-positive in early gestation

OBJECTIVE

The purpose of this study was to assess whether vaginal sialidases level in early pregnancy is associated with preterm birth among women who are bacterial vaginosis-positive.

STUDY DESIGN

Of the 1806 women who were enrolled at < 20 weeks of gestation, 800 of the women were bacterial vaginosis-positive (Nugent score, 7-10); 707 of the women had birth outcome data; 109 of the women who were bacterial vaginosis-positive had an adverse preterm outcome, which included 53 spontaneous preterm births (19 births were early at 20-34 weeks, and 34 births were late at 34-37 weeks), and 14 of the women had late miscarriages (12-20 weeks). Sialidase levels were compared with 352 control subjects (term normal birthweight infants).

RESULTS

Sialidase levels at ≥ 5, ≥ 10, and ≥ 14 nmol (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.01-2.41; OR, 2.14; 95% CI, 1.25-3.64; OR, 3.17; 95% CI, 1.64-6.10, respectively) was associated significantly with all adverse preterm outcomes. The ≥ 10 nmol and ≥ 14 nmol cut-points were associated strongly with early spontaneous preterm births (OR, 3.79; 95% CI, 1.42-10.10 and OR, 5.36; 95% CI, 1.77-16.23, respectively) and late miscarriages (OR, 4.87; 95% CI, 1.61-14.65; OR, 8.33; 95% CI, 2.57-26.9, respectively).

CONCLUSION

Elevated sialidase level that is measured at 12 weeks of gestation is associated strongly with early spontaneous preterm births and late miscarriage.

Periodontal disease and bacterial vaginosis as genetic and environmental markers for the risk of spontaneous preterm labor and preterm birth

OBJECTIVE

The aim of this study was to review the evidence associating periodontal disease, and bacterial vaginosis with preterm birth, and the link with gene polymorphism, as well as the preventions and interventions which might reduce the risk of spontaneous preterm labor and preterm births in women with periodontal disease and/or bacterial vaginosis.

BACKGROUND

Preterm birth accounts for 70% of perinatal mortality, nearly 50% of long term neurological morbidity, and a significant impact on health care costs. There is evidence that spontaneous preterm labor and preterm birth are associated with intrauterine infection due to abnormal genital and/or oral colonization. Periodontal disease and bacterial vaginosis share microbiological similarities, and both conditions are associated with spontaneous preterm labor and preterm birth. In addition, periodontal disease and bacterial vaginosis have been linked through gene polymorphism.

METHODS

A review of the literature using widely accepted scientific search engines in English language.

RESULTS

Studies evaluating antibiotic administration to eradicate periodontal disease and/or bacterial vaginosis responsible organisms, and minimize the risk of preterm births have yielded conflicting results. With respect to bacterial vaginosis, the timing and the choice of antibiotic administration might partly explain the conflicting results. The use of scaling and/or root planning for women with periodontal disease appears to reduce the risk of preterm birth, but routine administration of antibiotics has not demonstrated any impact on preterm birth.

CONCLUSION

Prospective studies evaluating the association of gene polymorphism with preterm birth, and the contribution of periodontal disease and bacterial vaginosis are needed.

Pregnancy complications associated with bacterial vaginosis and their estimated costs

Objective: This study was undertaken to estimate the annual direct costs of complications associated with bacterial vaginosis (BV) in pregnant women in the United States.

Methods: An economic model was developed from evidence in the published literature linking perinatal complications to BV. The estimates of attributable risks were applied to the estimated population of pregnant women in the United States in 1993. The charge data from a database of hospital utilization information were then used to estimate the direct costs of each pregnancy complication and the total direct costs associated with BV.

Results: Under the assumptions of our model, the direct costs of preterm labor, preterm delivery, the attendant low birth weight (LBW), and other perinatal complications associated with BV were estimated at nearly $1.0 billion in 1993. Over 40% of the total cost was associated with preterm delivery and intensive care of LBW infants, while another 24.5% of the cost was related to preterm labor.

Conclusions: If the current frequency of BV among pregnant women persists and BV is not detected and treated during pregnancy, the projected annual costs will reach $1.4 billion by the year 2000. Reducing the heavy economic burden associated with BV in pregnant women will require the establishment of effective screening and treatment regimens.

Mycoplasma genitalium among young, urban pregnant women

Objective. As the consequences of Mycoplasma genitalium in pregnant women are unknown, we examined the relationship between prenatal M. genitalium infection and SAB. Methods. The presence of M. genitalium was determined by PCR in urine from 82 women who subsequently experienced a SAB and 134 women who maintained their pregnancies past 22 weeks gestation. The relationships between M. genitalium and subsequent SAB, demographic, current pregnancy, and reproductive health history characteristics were evaluated. Results. Compared to women without M. genitalium, women with M. genitalium were more likely to report nulliparity (41.7% versus 17.4%, P = .04), history of pelvic inflammatory disease (27.3% versus 8.8%, P = .08), prior C. trachomatis infection (63.6% versus 36.9%, P = .11,) and problems getting pregnant (18.2% versus 4.4%, P = .10). M. genitalium was not associated with SAB (AOR 0.9, 95% CI 0.2–3.8). Conclusions. Pregnant women who test positive for M. genitalium do not have an increased risk of SAB but report a history of reproductive morbidities.

Vaginal and oral microbes, host genotype and preterm birth

Preterm birth (PTB) is a leading cause of infant mortality and morbidity in the US and across the globe. Infection and associated inflammation are important initiators for PTB pathways; an estimated 40% of PTBs are attributed to amniochorionic-decidual or systemic inflammation. Historically, intrauterine infections have been implicated in PTB; recent evidence suggests that infections remote from the fetal site may also be causative. There is strong epidemiological evidence that bacterial vaginosis and periodontitis--two syndromes characterized by perturbations in the normal vaginal and oral bacterial microflora, respectively--are linked to infection-associated PTB. Oral and vaginal environments are similar in their bacterial microbiology; identical bacterial species have been independently isolated in periodontitis and bacterial vaginosis. Periodontitis and bacterial vaginosis also share many behavioral and sociodemographic risk factors suggesting a possible common pathophysiology. Genetic polymorphisms in host inflammatory responses to infection are shared between bacterial vaginosis, periodontitis and PTB, suggesting common mechanisms through which host genotype modify the effect of abnormal bacterial colonization on preterm birth. We review the state of knowledge regarding the risk of PTB attributable to perturbations in bacterial flora in oral and vaginal sites and the role of host genetics in modifying the risk of infection-related PTB. We posit that bacterial species that are common in perturbed vaginal and oral sites are associated with PTB through their interaction with the host immune system.

The bacteriology of pre-labour rupture of membranes in a Nigerian teaching hospital

A prospective case control study that was conducted at the University of Ilorin Teaching Hospital, Ilorin, Nigeria, between 1st January and 31st December 2002. The purpose of this study was to determine the association and the pattern of bacteria/microorganisms in the aetiology of pre-labour premature rupture of membrane (PROM) in this centre. A total of 108 cases of PROM and 98 control cases that presented between 37 completed weeks' and 40 weeks' gestation were analysed. Pathogens were isolated in 48 patients, giving a recovery rate of 44.4%. The common pathogens include Gardnerella vaginalis (29.1%), Candida (23.0%) and Staphylococcus aureus (18.7%). Others were Streps. Pyogenes (16.6%), coagulase negative staphylococcus (CONS) (6.3%) and Klebsiella (6.3%). Only Candida and S. aureus were isolated in the controls. Ofloxacin and azithromycin were 100% active against all the isolated pathogens, while ampicillin was the least active. G. vaginalis was the most sensitive among the isolates while CONS and Klebsiella were the least sensitive. It is evident in this study that some pathogens were associated with PROM and that G. vaginalis was the most common organism and azithromycin was the only antibiotic with 100% sensitivity. We suggest that metronidazole should be added to azithromycin to cover for anaerobes in cases of PROM, where facilities for screening for anaerobes are not available.

Bacterial vaginosis diagnosed at the first antenatal visit better predicts preterm labour than diagnosis later in pregnancy

This study was conducted as part of a double-blind randomised placebo-controlled trial, the aim of which was to determine whether vitamin C could reduce the recurrence risk of pre-term labour. In this study, women with a history of pre-term labour in a preceding pregnancy were randomised to receive either 250 mg vitamin C or a matching placebo twice daily until 34 weeks' gestation. They attended a dedicated pre-term labour clinic every 2 weeks. All women were screened for bacterial vaginosis (BV) at each visit. It was first determined that vitamin C did not have any effect on the presence of BV. Women who were diagnosed with BV before 20 weeks' gestation were at higher risk of delivering pre-term than those who developed BV after 20 weeks.

Screening and management of bacterial vaginosis in pregnancy

OBJECTIVE

To review the evidence and provide recommendations on screening for and management of bacterial vaginosis in pregnancy.

OPTIONS

The clinical practice options considered in formulating the guideline.

OUTCOMES

Outcomes evaluated include antibiotic treatment efficacy and cure rates, and the influence of the treatment of bacterial vaginosis on the rates of adverse pregnancy outcomes such as preterm labour and delivery and preterm premature rupture of membranes.

EVIDENCE

Medline, EMBASE, CINAHL, and Cochrane databases were searched for articles, published in English before the end of June 2007 on the topic of bacterial vaginosis in pregnancy.

VALUES

The evidence obtained was rated using the criteria developed by the Canadian Task Force on Preventive Health Care.

BENEFITS, HARMS, AND COSTS

Guideline implementation will assist the practitioner in developing an approach to the diagnosis and treatment of bacterial vaginosis in pregnant women. Patients will benefit from appropriate management of this condition.

VALIDATION

These guidelines have been prepared by the Infectious Diseases Committee of the SOGC, and approved by the Executive and Council of the SOGC.

SPONSORS

The Society of Obstetricians and Gynaecologists of Canada.

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.

Prenatal exposure to maternal infections and epilepsy in childhood: a population-based cohort study

OBJECTIVE

We estimated the association between prenatal exposure to maternal infections and the subsequent risk for epilepsy in childhood.

METHODS

We included 90,619 singletons who were born between September 1997 and June 2003 in the Danish National Birth Cohort and followed them up to December 2005. Information on maternal infections during pregnancy (cystitis, pyelonephritis, diarrhea, coughs lasting >1 week, vaginal yeast infection, genital herpes, venereal warts, and herpes labialis) was prospectively reported by mothers in 2 computer-assisted telephone interviews in early and midgestation; information on maternal cystitis and pyelonephritis during late period of pregnancy was also collected in a third interview after birth. Children who received a diagnosis of epilepsy as inpatients or outpatients were retrieved from the Danish National Hospital Register. We identified 646 children with a diagnosis of epilepsy during up to 8 years of follow-up time. Cox proportional hazards regression models were used to estimate incidence rate ratio and 95% confidence interval.

RESULTS

Children who were exposed to maternal cystitis, pyelonephritis, diarrhea, coughs, and/or vaginal yeast infection some maternal infections in prenatal life had an increased risk for epilepsy. Coughs lasting >1 week were associated with an increased risk for epilepsy only in the first year of life, as was vaginal yeast infection only in children who were born preterm. These associations remained unchanged for children without cerebral palsy, congenital malformation, or a low Apgar score at 5 minutes.

CONCLUSIONS

Prenatal exposure to some maternal infections was associated with an increased risk for epilepsy in childhood.

Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery

BACKGROUND

Preterm birth is birth before 37 weeks' gestation. Genital tract infection is one of the causes of preterm birth. Infection screening during pregnancy has been used to reduce preterm birth. However, infection screening may have some adverse effects, e.g. increased antibiotic drug resistance, increased costs of treatment.

OBJECTIVES

To assess the effectiveness and complications of antenatal lower genital tract infection screening and treatment programs in reducing preterm birth and subsequent morbidity.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008) and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 2).

SELECTION CRITERIA

We included all published and unpublished randomised controlled trials in any language that evaluated any described methods of antenatal lower genital tract infection screening compared with no screening. Preterm births have been reported as an outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

One study (4155 women) met the inclusion criteria. This trial is of high methodological quality. In the intervention group (2058 women), the results of infection screening and treatment for bacterial vaginosis, trichomonas vaginalis and candidiasis were reported; in the control group (2097 women), the results of the screening program for the women allocated to receive routine antenatal care were not reported. Preterm birth before 37 weeks was significantly lower in the intervention group (3% versus 5% in the control group) with a relative risk (RR) of 0.55 (95% confidence interval (CI) 0.41 to 0.75). The incidence of preterm birth for low birthweight preterm infants with a weight equal to or below 2500 g and very low birthweight infants with a weight equal to or below 1500 g were significantly lower in the intervention group than in the control group (RR 0.48, 95% CI 0.34 to 0.66 and RR 0.34; 95% CI 0.15 to 0.75, respectively).

AUTHORS' CONCLUSIONS

There is evidence that infection screening and treatment programs in pregnant women may reduce preterm birth and preterm low birthweights. Future trials should evaluate the effects of types of infection screening program, gestational ages at screening test and the costs of introducing an infection screening program.

[Antimicrobial therapy associated with preterm birth]

The effect of 51 antimicrobial drugs was evaluated for the reduction of preterm birth.

STUDY DESIGN

Newborn infants without birth defects were selected from the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996, for the study. Medically recorded gestational age and the proportion of preterm birth were the primary outcomes of the study and newborn infants born to mothers with or without a given antimicrobial drug were compared.

RESULTS

The use of 51 antimicrobial drugs in the mothers of 38 151 newborn infants including at least ten pregnant women was evaluated. Only two: ampicillin and clotrimazole showed an obvious preterm birth preventive effect, mainly after the use during the first trimester of pregnancy.

CONCLUSIONS

Our findings suggest that ampicillin and particularly clotrimazole may be effective for the reduction of preterm birth associated with infectious diseases of pregnant women.

The relationship between resolution of asymptomatic bacterial vaginosis and spontaneous preterm birth in fetal fibronectin-positive women

OBJECTIVE

The purpose of this study was to determine the impact of persistent bacterial vaginosis (BV) on the occurrence of spontaneous preterm birth (SPB) in women who test positive for fetal fibronectin.

STUDY DESIGN

This is a secondary analysis of a subset of pregnant women who tested positive for BV and fetal fibronectin between 16(0/7) and 25(6/7) weeks of gestation and who participated in randomized placebo controlled trials of antibiotic therapy. Nugent's criteria were used for the diagnosis of BV. Patients were reassessed for the presence of BV after treatment. The rate of SPB at <34 weeks of gestation was analyzed on the basis of treatment mode and BV status at the follow-up visit.

RESULTS

The primary studies included a total of 3285 women. A subset of 215 women met the criteria for this analysis. Seventy-seven of 100 patients (77%) in the antibiotics group vs 33 of the 115 patients (28.7%) in the placebo group became BV negative (P < .0001). The rate of SPB at <34 weeks of gestation was lower for BV resolution compared with persistent BV (0 vs 5.7%, respectively; P = .01).

CONCLUSION

In women who tested positive for fetal fibronectin and BV, resolution of BV is associated with less SPB before 34 weeks of gestation.

Bacterial vaginosis and human immunodeficiency virus infection

Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission.

[The possible effect of ampicillin treatment in preventing preterm birth]

OBJECTIVE

To study the possible association between oral ampicillin treatment during pregnancy and pregnancy complications, in addition delivery outcomes, particularly preterm birth.

METHODS

The authors evaluated the so-called control newborn infants without congenital abnormalities in the population based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities.

RESULTS

Of 38,151 newborn infants, 2630 (6.9 %) had mothers with ampicillin treatment during pregnancy. Some pregnancy complications, particularly preeclampsia showed a higher prevalence in pregnant women with ampicillin treatment. Mean gestational age was slightly longer but it resulted in a significant reduction in the prevalence of preterm birth (7.1% vs 9.3 %; adjusted POR with 95 degrees % CI: 0.8, 0.7-0.9). The preterm birth preventive effect of ampicillin was most obvious after the use of the drug in the first trimester of pregnancy. Similar difference was not seen in the reduction of low birth weight.

CONCLUSION

Ampicillin treatment, particularly in the first trimester of gestation can reduce the proportion of preterm birth in pregnant women with acute infectious diseases.

Asymptomatic trichomonas and candida colonization and pregnancy outcome

Trichomonas vaginalis is a sexually transmitted surface pathogen of the lower urogenital tract, and may be associated with asymptomatic vaginal colonization or intensely symptomatic vaginitis. In pregnancy it is associated with an increased risk of preterm delivery. However, a randomized trial of treatment of asymptomatic trichomonas colonization in pregnancy showed an increase in the risk of preterm delivery in treated women. The reasons for this paradox are yet to be fully elucidated. Candida species, on the other hand, may be present--usually in the yeast form--in the vaginal flora of up to 40% of healthy pregnant women. Although candidiasis is not usually associated with chorioamnionitis or preterm delivery, there is some emerging evidence to suggest that screening for and eradication of candida during pregnancy may reduce the risk of preterm delivery. This chapter reviews the impact of these common vaginal infections on pregnancy outcome and appraises the recent evidence on the role of treatment during pregnancy.

Role of antibiotic therapy for bacterial vaginosis and intermediate flora in pregnancy

Bacterial vaginosis and intermediate flora are associated with late miscarriage and preterm delivery. The mechanisms involved are not yet fully understood. Clinical trials of antibiotic therapy to reduce these complications have yielded conflicting results. These trials, however, were conducted in mixed populations of pregnant women with variable risk profiles for preterm delivery. Furthermore, investigators used different criteria for diagnosis, treated with different antibiotics at different doses and via different routes, and initiated treatment at different gestational ages. Over 80% of pregnant women with abnormal vaginal flora have a good outcome, and in some populations the presence of bacterial vaginosis is not associated with preterm delivery, suggesting that other host factors may modify the risk. Recent studies have examined the roles of genetic regulation of host immune response, bacterial pathogenic factors, and enzymes in the vagina, and how these factors interact to drive a given outcome. These markers have the potential to better define the women at maximal risk and therefore guide future interventions. This chapter aims to appraise the current state of treatment of abnormal vaginal flora in pregnancy and suggest appropriate management based on the available evidence.

Bacterial vaginosis and host immunity

Bacterial vaginosis (BV) has been associated with severe medical consequences including induction of preterm birth and increasing susceptibility to infection by HIV and other genital tract pathogens. Although the mechanism by which BV induces these changes is not yet fully defined, the presence of BV is accompanied by immunologic changes in the lower genital tract environment. The most striking change is the induction of higher levels of proinflammatory cytokines, although this is not accompanied by increased levels of neutrophils. Increased cytokine levels are likely induced by bacterial products present in BV through innate immune recognition pathways such as the toll-like receptors. Recent studies show that changes in HIV susceptibility and HIV detection are associated with changes in bacterial flora. Further research is needed to identify the relative contributions of immune pathways and bacterial flora toward the pathogenic alterations that occur in BV.

First trimester bacterial vaginosis, individual microorganism levels, and risk of second trimester pregnancy loss among urban women

OBJECTIVE

To examine the role of first trimester bacterial vaginosis (BV) and level of BV-associated microorganisms, diagnosed using the Nugent gram stain criteria and the risk of second trimester pregnancy loss among urban women.

DESIGN

Prospective cohort study.

SETTING

Urban prenatal care clinics.

PATIENT(S)

Women presenting for their first prenatal care visit who had completed 12 weeks gestation or less and resided within Philadelphia, Pennsylvania.

MAIN OUTCOME MEASURE(S)

Pregnancy loss.

RESULT(S)

Of 1948 women enrolled at a mean gestational age of 10 weeks (range 7.4 to 12.6 weeks), those with the highest level of BV-related vaginal flora alteration compared with women with normal vaginal flora had over a twofold increased risk of second trimester pregnancy loss after adjustment for confounders (adjusted hazard ratio [aHR] 2.49, 95% confidence interval [CI] 1.13 to 5.48). Low Lactobacillus spp. and the absence of Lactobacillus spp. were also significantly related to the risk of second trimester pregnancy loss (aHR 1.32, 95% CI 1.10-1.64; aHR 2.30, 95% CI 1.09-4.85; respectively).

CONCLUSION(S)

Overall BV positivity was not related to second trimester pregnancy loss. Comparing the highest to lowest tertile of BV positivity in early pregnancy conferred a two-fold increased risk of second trimester pregnancy loss and low amounts or the absence of Lactobacillus spp. in the first trimester also significantly increased the risk of second trimester pregnancy loss.

The preterm parturition syndrome

The implicit paradigm that has governed the study and clinical management of preterm labour is that term and preterm parturition are the same processes, except for the gestational age at which they occur. Indeed, both share a common pathway composed of uterine contractility, cervical dilatation and activation of the membranes/decidua. This review explores the concept that while term labour results from physiological activation of the components of the common pathway, preterm labour arises from pathological signalling and activation of one or more components of the common pathway of parturition. The term "great obstetrical syndromes" has been coined to reframe the concept of obstetrical disease. Such syndromes are characterised by: (1) multiple aetiology; (2) long preclinical stage; (3) frequent fetal involvement; (4) clinical manifestations that are often adaptive in nature; and (5) gene-environment interactions that may predispose to the syndromes. This article reviews the evidence indicating that the pathological processes implicated in the preterm parturition syndrome include: (1) intrauterine infection/inflammation; (2) uterine ischaemia; (3) uterine overdistension; (4) abnormal allograft reaction; (5) allergy; (6) cervical insufficiency; and (7) hormonal disorders (progesterone related and corticotrophin-releasing factor related). The implications of this conceptual framework for the prevention, diagnosis, and treatment of preterm labour are discussed.

Is the presence of Trichomonas on a Pap smear associated with an increased incidence of bacterial vaginosis?

OBJECTIVE

Bacterial vaginosis (BV) is associated with significant morbidity. Bacterial vaginosis is due to an overgrowth of anaerobic organisms in the vagina. It has been postulated that the presence of Trichomonas creates an anaerobic environment that favors BV. Thus, BV should be more frequent in the presence of Trichomonas if Trichomonas is creating a favorable anaerobic environment.

MATERIALS AND METHODS

A retrospective review of Pap test reports was performed for a diagnosis of coccobacilli consistent with shift in vaginal flora, that is, the presence of clue cells. Cases were Pap smears with Trichomonas identified. Controls were cases without Trichomonas. Results were analyzed using Fisher exact test.

RESULTS

Four hundred cases were reviewed; 200 with and 200 without Trichomonas. The incidence of BV was significantly higher in the Trichomonas group (46.5%) than in group without Trichomonas (24.5%) (p < .0001.).

CONCLUSION

The presence of Trichomonas on a Pap smear is associated with an increased incidence of BV. The report of Trichomonas on a Pap smear should prompt clinical consideration that BV may be present.

Racial and ethnic disparities in potentially avoidable delivery complications among pregnant Medicaid beneficiaries in South Carolina

OBJECTIVES

To examine race and ethnicity differences in accessibility and effectiveness of health care during pregnancy.

METHODS

Data were 26,866 year 2000 Medicaid-insured deliveries from the South Carolina Office of Research and Statistics, and Area Resource File. The access indicator was Potentially Avoidable Maternity Complications (PAMCs). PAMC risks can be reduced through prenatal care, such as infection screening and treatment, and healthy behaviors it promotes. We compared PAMC risks of Blacks, Hispanics, and Whites. Analyses included PAMC rates, Chi-square, t-tests, multilevel logistic regression. Risks were estimated for ages 10-17, and 18+.

RESULTS

At ages 10-17 (n=2,691), Blacks and Hispanics had notably higher unadjusted and adjusted PAMC risks (adjusted odds ratios, ORs, 2.26, p < .001; 3.29, p < .05, respectively). At ages 18+, adjusted odds for Hispanics were about half those of Whites (p < .05). Adjusted odds for adult Blacks and Whites did not differ. This may be due to controlling for many risk factors that are more prevalent among Blacks: Single, disabled, poverty, diabetes, hypertension, rurality; however, unadjusted PAMC prevalence also did not differ greatly (3.9 for Blacks, 3.4 for Whites, p < .1). Adjusted risks were high for adults with diabetes (OR 2.40, p < .001) and all rural women (teen OR 4.02, p < .05; adult OR 1.83, p < .001).

CONCLUSIONS

Young Blacks and Hispanics have notably higher risks of delivery outcomes indicating less access to prenatal care of reasonable quality. Policies to reduce PAMCs in Medicaid should address needs of young Blacks and Hispanics; enhance diabetes treatment for adult women; and address rural access barriers for all women.

Perinatal infections and cerebral palsy

Infections of the mother, the intrauterine environment, the fetus, and the neonate can cause cerebral palsy through a variety of mechanisms. Each of these processes is reviewed. The recently proposed theory of cytokine-induced white matter brain injury and the systemic inflammatory response syndrome with multiple organ dysfunction syndrome is critically evaluated.

Readily treatable reproductive tract infections and preterm birth among black women

OBJECTIVE

This study sought to quantify the risks of preterm birth that are ascribable to potentially treatable reproductive tract infections among black women in Denver, Colorado.

STUDY DESIGN

A secondary analysis was conducted of 4 prospective studies in Denver, Colorado, that included 1038 women who were enrolled at < 29 weeks of gestation and whose cases were followed through delivery. Rates of preterm birth, preterm labor, and preterm premature rupture of membranes were the primary outcomes that were examined.

RESULTS

Bacterial vaginosis, infection with Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma hominis, Neisseria gonorrhoeae, and group B streptococcal colonization were more common among black women (P < .01) than among comparators. Preterm birth occurred more often among black women with infections that were being studied (20.4%), compared with uninfected black women (9.5%; relative risk, 2.2; 95% CI, 1.1-4.1). Up to 42% of preterm births among black women were attributable to the presence of bacterial vaginosis, T vaginalis, or C trachomatis alone or in combinations. The risk for preterm birth among infected black women who received Centers for Disease Control and Prevention recommended treatment was reduced significantly (relative risk, 0.16; 95% CI, 0.04-0.66).

CONCLUSION

Black women have increased risks of prematurity that are associated with prevalent reproductive tract infections during pregnancy. Preterm birth among similar urban black women could be reduced by > 40% by the screening and treatment of common genitourinary tract infections in pregnancy.

The possible preterm birth preventive effect of ampicillin during pregnancy

OBJECTIVE

To study the possible association between oral ampicillin treatment during pregnancy and pregnancy complications, in addition to birth outcomes, particularly preterm birth.

METHODS

We evaluated newborn infants without congenital abnormalities born to mothers with or without ampicillin treatment during pregnancy in the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities.

RESULTS

Of 38,151 newborn infants, 2,630 (6.9%) had mothers with ampicillin treatment during pregnancy. Some pregnancy complications, particularly preeclampsia, showed a higher prevalence in pregnant women with ampicillin treatment. Mean gestational age was slightly longer (0.2 week) but it resulted in a significant reduction in the prevalence of preterm birth (7.1 vs 9.3%; adjusted POR with 95% CI: 0.8, 0.7-0.9). The preterm birth preventive effect of ampicillin was most obvious after the use of the drug in the first trimester of pregnancy. Similar difference was not seen in the reduction of low birth weight. The rate of preterm birth was lower in newborn infants born to mothers with acute infectious diseases of both the genitourinary and respiratory systems if they were treated by ampicillin.

CONCLUSIONS

Ampicillin treatment, particularly in the first trimester of gestation, can reduce the proportion of preterm birth in pregnant women with acute infectious diseases of the genitourinary and respiratory system.

Detection of bacterial vaginosis, Trichomonas vaginalis infection, and vaginal Candida infection: a comparative study of methods of extracting exudates, with and without a speculum, during pregnancy

PURPOSE

To compare the collection of vaginal exudates with and without the use of a speculum to diagnose vaginal infections.

MATERIAL AND METHODS

We examined 45 patients with vaginal discharge. Two vaginal swabs were taken, one with and the other without a speculum. Both were examined by wet mount microscopy to detect bacterial vaginosis (BV), Trichomonas vaginalis, and the presence of blastospores with or without pseudomycelium.

RESULTS

A total of 90.9% of patients whose vaginal exudates were negative for BV when extracted with a speculum were also negative in the swab taken without a speculum. In the case of BV-positive exudates using a speculum, the correspondence was 90.5% with the swabs taken without a speculum. Among those exudates obtained with a speculum that were negative for Candida, 92.6% of those obtained without a speculum tested negative. In patients with pseudomycelium, when a speculum was used, 100% also presented a diagnosis of pseudomycelium from the swabs taken without a speculum. A concordance test between the techniques involving the use or nonuse of a speculum was performed for each of the diagnoses showed a good agreement according to the observed Kappa statistics (0.8467 and 0.8396 for BV and Candida, respectively).

CONCLUSIONS

A very good agreement between the results obtained with and without the use of a speculum was observed. Swabbing without the use of a speculum is especially convenient for pregnant women who require frequent testing for these types of infections during their pregnancies.

Management of genital infections in pregnant women

PURPOSE OF REVIEW

To examine and evaluate ways of managing genital infections in pregnant women.

RECENT FINDINGS

The need to screen for sexually transmitted diseases during pregnancy depends on the prevalence of the condition, its pathogenesis and the cost-benefit analysis for a population or risk group. For a few genital infections with severe impact on the outcome of the pregnancy, such as syphilis and gonorrhoea, a 'screen and treat' policy is almost always cost-effective.

SUMMARY

Genital infections often remain unnoticed during pregnancy, as their signs and symptoms may be seen as part of the normal discomfort of pregnancy. Also it is sometimes not clear whether there are multiple partners or whether the partners have been treated, making re-infection after treatment highly likely. Partner tracing may be difficult, but the 'screen and treat' policy is usually the best solution.

Periodontal therapy reduces the rate of preterm low birth weight in women with pregnancy-associated gingivitis

BACKGROUND

One hypothesis to explain the association between periodontal disease (PD) preterm/low birth weight (PT/LBW) is that PT/LBW may be indirectly mediated through translocation of bacteria or bacterial products in the systemic circulation. Transient bacteremias occur in subjects with marginal periodontitis or with gingivitis, and it is possible that bacteria and their products may reach the placental membranes hematogenously and provide the inflammatory effect to induce preterm labor. The effect of gingivitis as a potential risk factor for PT/LBW has still not been studied. A randomized controlled trial was undertaken to determine the effect of routine plaque control and scaling on the pregnancy outcomes in women with gingivitis.

METHODS

Eight hundred seventy (870) pregnant women with gingivitis, aged 18 to 42, were enrolled while receiving prenatal care in Santiago, Chile. Women were randomly assigned in a two-to-one fashion to either a treatment group (N = 580), receiving periodontal treatment before 28 weeks of gestation or to a control group (N = 290), receiving periodontal treatment after delivery. Periodontal therapy consisted of plaque control, scaling, and daily rinsing with 0.12% clorhexidine. Maintenance therapy was provided every 2 to 3 weeks until delivery, and consisted of oral hygiene instruction and supragingival plaque removal by instrumentation, as needed. The primary outcomes assessed were delivery at less than 37 weeks of gestation or an infant weighing less than 2,500 g.

RESULTS

Of the 870 women enrolled, 36 women (27 in the treatment group and nine in the control group) were excluded from the analyses for different reasons. The incidence of PT/LBW in the treatment group was 2.14% (12/560) and in the control group, 6.71% (19/283) (odds ratio [OR] 3.26; 95% confidence interval [CI] 1.56 to 6.83; P = 0.0009). Multivariate logistic regression analysis showed that, after adjusting for several known risk factors for PT/LBW, women with gingivitis were at a higher risk of PT/LBW than women who received periodontal treatment (OR 2.76; 95%CI 1.29 to 5.88; P = 0.008).

CONCLUSIONS

Periodontal treatment significantly reduced the PT/LBW rate in this population of women with pregnancy-associated gingivitis. Within the limitations of this study, we conclude that gingivitis appears to be an independent risk factor for PT/LBW for this population.

Effect of bacterial vaginosis on premature rupture of membranes and related complications in pregnant women with a gestational age of 37-42 weeks

BACKGROUND

The most serious outcome of term, premature rupture of membrane and chorioamnionitis is often associated with adverse maternal and infant outcomes related to infection. This study was undertaken to determine the prevalence of bacterial vaginosis (BV) at 37-42 gestational weeks and its relationship to premature rupture of membranes.

METHOD

During an analytical descriptive prospective study, 425 pregnant women with a gestational age of 37-42 weeks were studied for prevalence of BV. Then, 304 women on the basis of having BV or not were followed up until 48 h after delivery for premature rupture of membranes.

RESULT

The rate of BV in this population was 30.5%. No significant association was found between BV and premature rupture of membranes (odds ratio 1.6, 95% CI 0.9-2.8).

CONCLUSION

BV is a common vaginitis in term pregnancy, but we could not find any relationship between BV and premature rupture of membranes at term.