Mean Arterial Pressure and Neonatal Outcomes in Pregnancies Complicated by Mild Chronic Hypertension.

OBJECTIVE: To estimate the association between mean arterial pressure during pregnancy and neonatal outcomes in participants with chronic hypertension using data from the CHAP (Chronic Hypertension and Pregnancy) trial. METHODS: A secondary analysis of the CHAP trial, an open-label, multicenter randomized trial of antihypertensive treatment in pregnancy, was conducted. The CHAP trial enrolled participants with mild chronic hypertension (blood pressure [BP] 140-159/90-104 mm Hg) and singleton pregnancies less than 23 weeks of gestation, randomizing them to active treatment (maintained on antihypertensive therapy with a goal BP below 140/90 mm Hg) or standard treatment (control; antihypertensives withheld unless BP reached 160 mm Hg systolic BP or higher or 105 mm Hg diastolic BP or higher). We used logistic regression to measure the strength of association between mean arterial pressure (average and highest across study visits) and to select neonatal outcomes. Unadjusted and adjusted odds ratios (per 1-unit increase in millimeters of mercury) of the primary neonatal composite outcome (bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, or intraventricular hemorrhage grade 3 or 4) and individual secondary outcomes (neonatal intensive care unit admission [NICU], low birth weight [LBW] below 2,500 g, and small for gestational age [SGA]) were calculated. RESULTS: A total of 2,284 participants were included: 1,155 active and 1,129 control. Adjusted models controlling for randomization group demonstrated that increasing average mean arterial pressure per millimeter of mercury was associated with an increase in each neonatal outcome examined except NEC, specifically neonatal composite (adjusted odds ratio [aOR] 1.12, 95% CI, 1.09-1.16), NICU admission (aOR 1.07, 95% CI, 1.06-1.08), LBW (aOR 1.12, 95% CI, 1.11-1.14), SGA below the fifth percentile (aOR 1.03, 95% CI, 1.01-1.06), and SGA below the 10th percentile (aOR 1.02, 95% CI, 1.01-1.04). Models using the highest mean arterial pressure as opposed to average mean arterial pressure also demonstrated consistent associations. CONCLUSION: Increasing mean arterial pressure was positively associated with most adverse neonatal outcomes except NEC. Given that the relationship between mean arterial pressure and adverse pregnancy outcomes may not be consistent at all mean arterial pressure levels, future work should attempt to further elucidate whether there is an absolute threshold or relative change in mean arterial pressure at which fetal benefits are optimized along with maternal benefits. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02299414.

Vaginal-perianal or vaginal-perineal compared with vaginal-rectal culture-based screening for Group B Streptococci (GBS) colonization during the third trimester of pregnancy: a systematic review and meta-analysis.

BACKGROUND: Screening for maternal anogenital Group B streptococci (GBS) colonization in pregnancy with initiation of intravenous intrapartum antibiotic prophylaxis as indicated has led to a significant reduction in the incidence of neonatal GBS infection. This study aims to evaluate the agreement between vaginal-perianal or vaginal-perineal culture and the more typically used vaginal-rectal culture for screening for maternal anogenital GBS colonization in the third trimester of pregnancy. METHODS: Eligible English-language studies published until January 2020 were retrieved from Scopus, Web of Science, PubMed, Embase, and ClinicalTrials.gov databases. Studies were compiled that assessed for GBS colonization utilizing vaginal-perianal or vaginal-perineal culture and vaginal-rectal culture during the third trimester of pregnancy. Nonoriginal research articles and studies that did not assess pregnant patients, did not use culture-based screening, or did not compare vaginal-perianal or vaginal-perineal culture with vaginal-rectal culture were excluded. The search identified 559 articles with three prospective cohort studies that met inclusion criteria, including 643 participants. Quality was assessed using the Newcastle-Ottawa Scale, and risk of bias was assessed using the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Patient characteristics and associated pain with specimen collection were abstracted. Meta-analyses of both the raw agreement and the Cohen's kappa statistic were performed. RESULTS: Within the three included studies, the range of GBS detection was 17.6-34.0%, consistent with the anticipated prevalence of GBS colonization reported in earlier publications. For both raw agreement and Cohen's kappa coefficient, the test for heterogeneity was not significant, indicating low heterogeneity among studies. The pooled estimate of the raw agreement was 0.97 (95%CI 0.95-0.98) and of the Cohen's kappa coefficient was 0.91 (95% CI: 0.87-0.95), indicating (according to the Landis and Koch criteria) an "almost perfect" agreement between the compared clinical tests. In the two studies that assessed procedure-related patient discomfort, vaginal-rectal swabbing caused more discomfort. CONCLUSION: Use of vaginal-perineal culture for assessment of maternal GBS colonization is comparable to the more typically utilized vaginal-rectal culture and is associated with less discomfort.

Class III Obese Women's Preferences and Concerns for Cesarean Skin Incision: A Multicenter Survey.

Objective This study aims to assess class III obese women's preferences and concerns regarding cesarean delivery (CD) skin incisions. Study Design Through the National Perinatal Research Consortium (NPRC), women with body mass index ≥ 40 kg/m2 at the time of enrollment completed an anonymous survey in English or Spanish. We evaluated seven domains of preferences and concerns about the cesarean skin incision. Results We surveyed 546 women at five NPRC sites. Median age (interquartile range) was 29 (25, 35) years; 364 (66%) were parous and 161 (30%) had a prior CD. Women self-identified race/ethnicity as White (31%), non-Hispanic Black (31%), Hispanic (31%), other (6%), and not reported (1%). A total of 542 women (99%) rated both delivering the baby in the best possible condition and decreasing incision opening/infection risk as important. Women were less likely to rate other domains as important (all p < 0.001), including: having least pain possible, n = 521 (95%); decreasing the risk of complications in the next pregnancy, n = 490 (90%); decreasing interference with breastfeeding, n = 474 (87%); decreasing operative time, n = 388 (71%); and having the least visible incision, n = 369 (68%). Conclusion Women with class III obesity prioritize immediate maternal and fetal safety regarding CD skin incision over other concerns including cosmetic outcome.

Obesity and Neonatal Cord Blood Gas Results at Cesarean: Effect of Intraoperative Blood Pressure.

Objective Our aims were to evaluate whether there is an inverse association between body mass index (BMI) and umbilical artery pH and to investigate the contribution of intraoperative hypotension on the umbilical artery pH. Study Design We conducted a retrospective cohort study of all women with a nonanomalous singleton at 37 to 41 weeks who underwent a scheduled cesarean delivery under spinal anesthesia at our facility from January 2006 to March 2012. The primary outcome was the proportion of patients in each BMI category with arterial cord pH < 7.10. Intraoperative blood pressure data were compared across BMI categories. Results In total, 717 mother-infant pairs met enrollment criteria. Mean arterial pH was significantly lower in women with elevated BMI (p = 0.014), notably with BMI ≥ 40 kg/m2. Baseline blood pressure increased linearly with increasing BMI (p < 0.001), however, so did the maximum drop in all blood pressure parameters (p < 0.001). After adjusting for potential confounders, including blood pressure, there was no longer an association between cord pH and BMI (p = 0.72). Conclusion For women undergoing a scheduled cesarean delivery under spinal anesthesia, umbilical artery pH is lower in women with BMI ≥40 kg/m2. Relative hypotension after spinal anesthesia is more pronounced with increasing BMI and may explain this effect.

Trisomy 18: A survey of opinions, attitudes, and practices of neonatologists.

We conducted a survey-based study of the opinions, attitudes, and management practices of neonatologists across the United States regarding prenatally diagnosed Trisomy 18. The survey was designed based on previously validated surveys of severe fetal anomalies and collected demographic information on participants, as well as their attitudes, and management choices given a series of vignettes beginning in the prenatal period. The survey was sent to 3,143 American Academy of Pediatrics Section on Neonatal-Perinatal Medicine members of which 409 (13%) completed the survey. While the response rate was rather low, our respondent pool was representative of the national neonatologist population. Respondents were predominately white (81%), married (88%), Christian (54%), had children (86%), and were pro-choice in terms of abortion (68%). Eighty-three percent (83%) of respondents thought that trisomy 18 is a lethal condition and 60% thought that treatment is futile. Seventy-five percent (75%) expected that the best neurodevelopmental outcome in the case of infant survival would be profound intellectual disability. Regarding neonatal care, 95% stated that they would recommend palliative care only. Ninety-five percent (95%) would never recommend or recommend only if asked full code resuscitation for a neonate with full trisomy 18, yet, 44% would comply partially or in full with a full code request for resuscitation measures. The demographic features that correlated most significantly with these responses were clinician race and years in practice. The attitudes toward and management of infants affected with trisomy 18 seem to be largely driven by parental attitudes and wishes. © 2016 Wiley Periodicals, Inc.

Evaluation of Human Papillomavirus as a Risk Factor for Preterm Birth or Pregnancy-Related Hypertension.

OBJECTIVE: To compare rates of preterm birth and pregnancy-related hypertension in women with and without human papillomavirus (HPV) infection. METHODS: We performed a retrospective cohort study of all women delivered at our institution in 2013 who had cervical cancer screening test results within 3 years before delivery. Patients were excluded if they had prior procedure(s) for cervical dysplasia other than biopsy. There were two primary outcomes: preterm birth (less than 37 weeks of gestation) and pregnancy-related hypertension (gestational hypertension, preeclampsia, or eclampsia). Multivariable logistic regression was performed to adjust for confounders including demographic variables, diabetes, prior preterm birth, chronic hypertension, and other genital infections. Assuming a 10% prevalence of HPV, a rate of 12% in the HPV-negative group for both preterm birth and pregnancy-related hypertension, α of 0.05, and ß of 0.2, we needed 2,207 patients to detect a 60% increase in the rate of either outcome in the HPV-positive group. RESULTS: A total of 3,958 patients delivered in 2013, of whom 2,321 met eligibility criteria, 242 (10.4%) of whom were HPV-positive and 2,079 (89.2%) of whom were HPV-negative. In multivariate analyses, the rate of preterm birth was not significantly different between HPV-positive and HPV-negative women (16.5% compared with 12.2%, adjusted odds ratio [OR] 1.3, 95% confidence interval [CI] 0.9-1.9); rates of pregnancy-related hypertension also were not significantly different between HPV-positive and HPV-negative women (17.0% compared with 16.4%, adjusted OR 1.0, 95% CI 0.7-1.5). CONCLUSION: Maternal HPV infection is not an independent risk factor for preterm birth or pregnancy-related hypertension.

Revisiting the cost-effectiveness of universal cervical length screening: importance of progesterone efficacy.

BACKGROUND: Preterm birth (PTB) is a significant cause of neonatal morbidity and mortality. Studies have shown that vaginal progesterone therapy for women diagnosed with shortened cervical length can reduce the risk of PTB. However, published cost-effectiveness analyses of vaginal progesterone for short cervix have not considered an appropriate range of clinically important parameters. OBJECTIVE: To evaluate the cost-effectiveness of universal cervical length screening in women without a history of spontaneous PTB, assuming that all women with shortened cervical length receive progesterone to reduce the likelihood of PTB. STUDY DESIGN: A decision analysis model was developed to compare universal screening and no-screening strategies. The primary outcome was the cost-effectiveness ratio of both the strategies, defined as the estimated patient cost per quality-adjusted life-year (QALY) realized by the children. One-way sensitivity analyses were performed by varying progesterone efficacy to prevent PTB. A probabilistic sensitivity analysis was performed to address uncertainties in model parameter estimates. RESULTS: In our base-case analysis, assuming that progesterone reduces the likelihood of PTB by 11%, the incremental cost-effectiveness ratio for screening was $158,000/QALY. Sensitivity analyses show that these results are highly sensitive to the presumed efficacy of progesterone to prevent PTB. In a 1-way sensitivity analysis, screening results in cost-saving if progesterone can reduce PTB by 36%. Additionally, for screening to be cost-effective at WTP=$60,000 in three clinical scenarios, progesterone therapy has to reduce PTB by 60%, 34% and 93%. Screening is never cost-saving in the worst-case scenario or when serial ultrasounds are employed, but could be cost-saving with a two-day hospitalization only if progesterone were 64% effective. CONCLUSION: Cervical length screening and treatment with progesterone is a not a dominant, cost-effective strategy unless progesterone is more effective than has been suggested by available data for US women. Until future trials demonstrate greater progesterone efficacy, and effectiveness studies confirm a benefit from screening and treatment, the cost-effectiveness of universal cervical length screening in the United States remains questionable.

Survey of American obstetricians regarding group B streptococcus: opinions and practice patterns.

OBJECTIVE: The objective of the study was to evaluate attitudes and practice patterns of obstetricians related to screening for group B streptococcal colonization and providing intrapartum antibiotic prophylaxis against early-onset neonatal infections with group B streptococcus. STUDY DESIGN: We mailed a survey to 546 members of the American College of Obstetricians and Gynecologists, including members of the Collaborative Ambulatory Research Network and non-Collaborative Ambulatory Research Network members. Stratified random selection was used to generate samples from both of these groups. RESULTS: The survey response rate was 60% for Collaborative Ambulatory Research Network members and 42% for non-Collaborative Ambulatory Research Network members. Of the 206 respondents who reported providing prenatal care, 97% collect screening samples at 35-37 weeks' gestational age. Anatomic sites used to collect samples were more variable: 62% include lower vagina and rectum, 26% include lower vagina and perianal skin but not rectum, and 5% include neither the perianal skin nor the rectum. First-line agents for intrapartum antibiotic prophylaxis were penicillin (71%), ampicillin (27%), and cefazolin (2%). For patients reporting a nonanaphylactic penicillin allergy, drugs used for intrapartum antibiotic prophylaxis were more varied: cefazolin (51%), clindamycin (36%), vancomycin (8%), and erythromycin (5%). For patients undergoing a labor induction starting with a cervical ripening agent, less than 40% typically give the first dose of intrapartum antibiotic prophylaxis before or at the time of cervical ripening agent administration, and 15% wait until the patient reaches the active phase of labor. CONCLUSION: Gaps in knowledge and reported practice related to the prevention of early-onset neonatal group B streptococcus infections were similar to gaps in implementation of guidelines demonstrated in past studies. New approaches to improve implementation are warranted.

Predicting fetal acidemia using umbilical venous cord gas parameters.

OBJECTIVE: To assess the utility of umbilical cord venous blood gas measures for prediction of umbilical artery pH and base deficit acidemia. METHODS: A retrospective cohort study was conducted of all singletons with valid paired arterial and venous cord gas samples delivered at our institution from January 2006 to March 2012. Fetal acidemia was defined primarily as cord arterial blood gas pH less than 7.0. We also evaluated prediction of acidemia, defined as an arterial base deficit 12 mmol/L or greater. Logistic regression was performed to estimate probabilities of fetal arterial pH and base deficit acidemia given venous blood gas pH or base deficit. Receiver operating characteristic curves were derived to determine predictive ability. Venous blood gas pH and base deficit cutoffs associated with 1% or less, 5%, 10%, and 50% probability of fetal acidemia were identified. RESULTS: Of 23,506 births, 11,455 (49%) met criteria for inclusion. The frequency of arterial blood gas pH less than 7.0 was 127 (1.1%); arterial blood gas base deficit 12 mmol/L or greater was 245 (2.1%). Venous blood gas pH (area under the curve [AUC] 0.949, 95% confidence interval [CI] 0.920-0.979; P<.001) and base deficit (AUC 0.969, 95% CI 0.954-0.983; P<.001) were predictors of acidemia based on arterial blood gas pH and base deficit, respectively. Venous blood gas pH cutoffs associated with 1% or less, 5%, or 10% probabilities of arterial blood gas pH less than 7.0 were 7.23, 7.17, and 7.14, respectively. Venous blood gas base deficit values associated with similar probabilities for base deficit 12 mmol/L or greater were 6.3 or less, 8.2 or less, and 9.0 mmol/L or less. For prediction of arterial blood gas pH, adjusting venous blood gas pH for base deficit increased the AUC (0.961, 95% CI 0.938-0.984). Prediction of arterial blood gas base deficit by venous blood gas base deficit was unchanged by adjustment for pH (AUC 0.969, 95% CI 0.955-0.984). CONCLUSION: We demonstrate that venous blood gas parameters are powerful predictors of arterial blood gas pH and base deficit and can be used to predict the likelihood of fetal acidemia when the cord arterial blood gas is not available.

Carboxymethylcellulose adhesion barrier placement at primary cesarean delivery and outcomes at repeat cesarean delivery.

OBJECTIVE: To assess associations of a commercially available carboxymethylcellulose adhesion barrier placed during primary cesarean delivery with clinical outcomes of repeat cesarean deliveries. METHODS: We performed a retrospective cohort study of women undergoing primary cesarean delivery on or after January 1, 2008, and first repeat cesarean delivery in one of four hospitals in the same system by June 30, 2011. Women were included if both deliveries were live singletons at 34-42 weeks of gestation delivered through transverse abdominal incisions and the first hysterotomy was low transverse. Exclusion criteria included intervening delivery; puerperal infection, bowel injury, or bladder injury at primary cesarean delivery; uterine incision or laparotomy (except primary cesarean delivery) before repeat cesarean delivery; and use of another adhesion barrier at primary cesarean delivery. As a surrogate for adhesion grading, the primary outcome was time from skin incision to neonate delivery at repeat cesarean delivery. We also assessed total operative time and rates of selected surgical complications. RESULTS: There were 517 women who met criteria; 248 received the adhesion barrier during primary cesarean delivery and 269 did not. There were no demographic differences between groups except delivery hospital. In the adhesion barrier and no adhesion barrier groups, respectively, mean±standard deviation times to delivery at repeat cesarean delivery were 6.1±3.0 compared with 5.8±2.5 minutes (P=.25), and total operative times were 31.2±10.6 compared with 31.8±11.6 minutes (P=.56). Surgical complications were not different between groups. CONCLUSION: Placing a commercially available carboxymethylcellulose adhesion barrier at primary cesarean delivery is not associated with decreased time to delivery, total operative time, or complications during repeat cesarean deliveries. LEVEL OF EVIDENCE: II.

The association of maternal obesity with fetal pH and base deficit at cesarean delivery.

OBJECTIVE: To evaluate the association between maternal body mass index (BMI) and umbilical cord acid-base status at the time of cesarean delivery. METHODS: We conducted a retrospective multicenter cohort study using data from the Cesarean Section Registry of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Women were included if they delivered a live, nonanomalous singleton at 37-41 weeks of gestation by prelabor cesarean under spinal anesthesia. We excluded women with diagnoses that might be associated with uteroplacental insufficiency. Body mass index at delivery was examined both as a continuous and categorical exposure, and acid-base status was based on cord arterial pH and base deficit. RESULTS: There were 5,742 mother-neonate pairs who met criteria for analysis. Among possible confounders (including sociodemographic variables, number of previous uterine incisions, diabetes, hematocrit, neonatal gender, and birth weight), African American race, birth weight, parity, and smoking status were significantly associated with both BMI and acid-base parameters. Adjusted for those four factors, with increasing BMI category (less than 25, 25-29.9, 30-34.9, 35-39.9, and 40 or higher), mean pH decreased from 7.25 to 7.22 (P<.001), proportion with pH less than 7.1 increased from 3.5% to 7.7% (P=.011), mean base deficit increased from 4.01 mmol/L to 4.83 mmol/L (P=.030), and proportion with base deficit of 12 mmol/L or more increased from 0.6% to 4.7% (P=.003). When BMI was analyzed continuously and adjusted for these confounders, for every 10-unit increase in BMI, cord arterial pH decreased by 0.01 (P<.001) and base deficit increased by 0.26 mmol/L (P=.005). CONCLUSION: For women undergoing nonemergent prelabor cesarean delivery under spinal anesthesia, fetal pH declines and base deficit rises as maternal BMI increases. LEVEL OF EVIDENCE: II.

Assessment of the value of rescreening for syphilis in the third trimester of pregnancy.

OBJECTIVES: Our aim is evaluating the need for repeating tests for syphilis on pregnant women in the third trimester. STUDY DESIGN: A single-center retrospective cohort study was performed on all women delivering 7/03-6/04. RESULTS: During the study interval, 2244 women delivered at our hospital. Of those women having available records and attending at least one prenatal visit, 1940 (98.9%) were screened for syphilis at the first prenatal visit. Of the 1627 women beginning prenatal care prior to 27 weeks and delivering after 32 weeks, 1377 (84.6%) were rescreened in the third trimester. No cases of syphilis were identified with either the initial (upper limit of 95% CI 0.24%) or repeat (upper limit of 95% CI 0.34%) screening. CONCLUSIONS: In our obstetric population, syphilis is so uncommon that mandated prenatal screening on more than one occasion seems unjustified and laws requiring repeated screening should be reevaluated.

The interleukin-6--174 single nucleotide polymorphism: cervical protein production and the risk of preterm delivery.

OBJECTIVE: The purpose of this study was to determine the associations between preterm delivery (PTD), cervical fluid interleukin-6 (IL-6) concentration, and the single nucleotide polymorphism at position -174 in the IL-6 gene. STUDY DESIGN: Cervical fluid samples were obtained from women 23 to 32 weeks' gestation with symptoms of preterm labor. Concentrations of IL-6 were determined by enzyme-linked immunosorbent assay (ELISA). IL-6 genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. RESULTS: One hundred thirty-seven women were enrolled, and complete information was available for 126. Cervical fluid IL-6 concentrations were not elevated in women destined to have a spontaneous PTD ( P = .86). IL-6 -174 genotype was not associated with PTD ( P = .62) or cervical fluid IL-6 concentration ( P = .36). Neonatal IL-6-174 genotype was not associated with PTD or IL-6 concentration. CONCLUSION: Cervical fluid concentrations of IL-6 were not elevated in symptomatic women destined to have a spontaneous PTD. The presence of maternal IL-6 -174C was not associated with cervical fluid concentration of IL-6 or risk of PTD.

Is perioperative hypothermia a risk factor for post-Cesarean infection?

OBJECTIVE: To determine whether hypothermia during Cesarean delivery is a risk factor for postoperative infection. METHODS: An historical cohort investigation was conducted on all women delivered by Cesarean at our center during 2001. Initial recovery-room temperature, taken via the oral or axillary route, was used as a surrogate for intraoperative temperature. Adding 0.5 degrees C to axillary temperatures generated oral temperature equivalents. Women with chorioamnionitis were excluded, as were those with an initial recovery-room temperature that exceeded 37.9 degrees C or was recorded more than 20 minutes after the end of surgery. Prophylactic antibiotics (cefazolin, 1 g) were given during Cesarean delivery. RESULTS: A total of 42 women (7.6%) were diagnosed with postoperative infections. Infections included endometritis (n = 25), wound abscess (n = 7), wound cellulitis (n = 7) and urinary tract infection (UTI) (n = 4). No cases of septic pelvic thrombophlebitis or pelvic abscess occurred. One woman had both endometritis and a UTI. Mean temperatures were higher, rather than lower, for women who subsequently had postoperative infections compared with those who did not (36.4 +/- 0.8 degrees C vs. 35.9 +/- 0.7 degrees C; p < 0.001). Mean temperatures for the various postoperative infections were as follows: endometritis, 36.5 +/- 0.8 degrees C (p < 0.001 vs. uninfected group); wound abscess 36.0 +/- 0.8 degrees C (p = 0.63); wound cellulitis, 36.3 +/- 0.6 degrees C (p = 0.14); UTI, 36.7 +/- 0.9 degrees C (p = 0.04). CONCLUSIONS: Women who develop post-Cesarean infections have higher initial recovery-room temperatures than those who do not develop such infections. This suggests the presence of subclinical infection at the time of Cesarean. Evaluating whether intraoperative warming has any role during Cesarean delivery requires a randomized clinical trial.

Intrapartum antibiotic prophylaxis 2: positive predictive value of antenatal group B streptococci cultures and antibiotic susceptibility of clinical isolates.

OBJECTIVE: To estimate the probability of positive intrapartum group B streptococcus cultures among women previously identified as carriers of this organism, and to estimate the susceptibility of group B streptococci to six commonly used antibiotics. METHODS: We performed a prospective cohort study of women identified as carriers of group B streptococci by current pregnancy genital tract (group 1) or urine cultures (group 2), or a positive culture in a prior pregnancy (group 3). Intrapartum culture specimens were obtained, and isolates were tested for susceptibility to six antibiotics using the agar disk diffusion technique. RESULTS: Intrapartum cultures were positive for 68% (62, 73), 61% (49, 72), and 48% (36, 60) of groups 1 (n = 249), 2 (n = 69), and 3 (n = 59), respectively. Cultures were positive in 67% (61, 73) of women in group 1 whose cultures were done 42 days or less before delivery (n = 218). The proportion of isolates (n = 239) susceptible to penicillin, ampicillin, cefazolin, and vancomycin was 100% (98, 100). The proportion susceptible to clindamycin and erythromycin was 91% (87, 94) and 79% (73, 84), respectively. CONCLUSION: The positive predictive value of antenatal group B streptococci cultures is lower than was previously reported. Clindamycin and erythromycin are not optimal agents for prophylaxis against early-onset neonatal group B streptococcal infection in patients who are allergic to penicillin.

Antimicrobial susceptibility of Gram-negative uropathogens isolated from obstetric patients.

OBJECTIVE: To evaluate the antimicrobial susceptibility of Gram-negative uropathogens isolated from pregnant women. METHODS: We performed a snapshot cohort study of women receiving care in the University of Florida prenatal clinics during March 2000. Subjects with asymptomatic bacteriuria or cystitis were identified and the antimicrobial susceptibility of each pathogen was recorded. Data were analyzed using chi-square, Fisher's exact test and ninety-five percent confidence intervals, as appropriate. RESULTS: Ninety-five positive cultures were identified. Isolates were more often susceptible to trimethoprim-sulfamethoxazole (TMP-SMX) (87%) and nitrofurantoin (89%) than to ampicillin (72%) (p < 0.03). Escherichia coli accounted for 71 (75%) cases and was more often susceptible to nitrofurantoin (100%) than to TMP-SMX (87%) (p < 0.01). Proteus isolates were all susceptible to TMP-SMX and resistant to nitrofurantoin (p < 0.01). CONCLUSIONS: Both TMP-SMX and nitrofurantoin are superior to ampicillin for empiric treatment of lower urinary tract infection in pregnant women. Nitrofurantoin is superior to TMP-SMX for treatment of infections caused by E. coli. For suspected or confirmed cases caused by Proteus organisms, TMP-SMX is the preferred agent.