R. Phillips Heine

Lower genital tract infection and endometritis: Insight into Subclinical pelvic inflammatory disease

OBJECTIVE To investigate the association between lower genital tract infections and subclinical PID. Fallopian tube damage is a common complication of acute symptomatic pelvic inflammatory disease (PID), yet most women with tubal factor infertility do not have a history of acute PID. Subclinical PID is believed to be an important cause of tubal factor infertility. METHODS We conducted a cross‐sectional study among women attending a sexually transmitted diseases or ambulatory gynecology clinic. A convenience sample of 556 women with bacterial vaginosis, gonorrhea, or chlamydia, or women at risk for gonorrhea or chlamydia were enrolled. Women diagnosed with acute PID were not eligible to participate. The main outcome was subclinical PID, as defined by the presence of histologic endometritis. RESULTS Subclinical PID was more common in women with lower genital tract infection than in uninfected women. Subclinical PID was present in 27% of women with Chlamydia trachomatis (odds ratio 3.4; 95% confidence interval [CI] 1.8, 6.3) and in 26% of women infected with Neisseria gonorrhoeae (odds ratio 2.4; 95% CI 1.1, 5.1). Among women with bacterial vaginosis, 15% had endometritis (odds ratio 2.7; 95% CI 1.02, 7.2). CONCLUSION Subclinical PID is common among women with lower genital tract infections. Additional prospective studies are necessary to determine the reproductive impact of these asymptomatic upper genital tract infections.

Self-collection of Vaginal Swabs for the Detection of Chlamydia, Gonorrhea, and Trichomoniasis: Opportunity to Encourage Sexually Transmitted Disease Testing Among Adolescents

Background Many sexually transmitted diseases (STDs) are prevalent among adolescents, yet compliance to undergo STD testing by this population is suboptimal. Efforts to enhance compliance with testing among at-risk youth are needed. Goal To determine the feasibility and acceptability of self-collection of vaginal swabs for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among high-school students attending a school health clinic. Study Design Enrolled in the study were 228 female students between the ages of 15 and 19 years. Each student self-collected a single vaginal swab that was tested for C trachomatis, N gonorrhoeae, and T vaginalis by polymerase chain reaction amplification. Acceptability of self-collection of vaginal swabs was assessed. Results The prevalence of any STD was 18%. Trichomoniasis, chlamydia, and gonorrhea were diagnosed in 10%, 8%, and 2% of students, respectively. Nearly 13% of females who had never previously had a gynecologic examination tested positive for an STD, and 51% of infected students would not have pursued testing by traditional gynecologic examination if self-collection was not offered. Self-collection of vaginal swabs was almost uniformly reported as easy to perform (99%) and preferable to a gynecologic examination (84%). Nearly all (97%) stated that they would undergo testing at frequent intervals if self-testing were available. Conclusions Self-collected vaginal swabs for STD testing can be easily implemented in a high-school setting with high acceptability among students, enabling the detection of many STDs that would otherwise remain undetected and untreated.

Maternal serum cytokines in preterm premature rupture of membranes.

OBJECTIVE: To estimate whether maternal serum interleukin (IL)-6 or granulocyte colony-stimulating factor (G-CSF) obtained daily are elevated in women with preterm premature rupture of membranes who develop funisitis. METHODS: Daily blood samples were obtained from women with preterm premature rupture of membranes and analyzed for IL-6 and G-CSF by enzyme-linked immunosorbent assay. Funisitis was determined by placental examination. Observations were stratified based on the presence or absence of funisitis and analyzed. Proportional hazards models were used to evaluate time-to-delivery on the basis of diagnostic IL-6 and G-CSF levels, determined by receiver operating characteristic curve analysis. RESULTS: Of the 107 patients available for analysis, 54 (50%) had evidence of funisitis after delivery. Patients with funisitis were more likely to deliver at an earlier gestational age (28.5 weeks compared with 31.5 weeks, P<.001) and have Medicaid insurance (57% compared with 39%, P=.04). Serum IL-6 and G-CSF were elevated 24 to 48 hours before delivery in women with preterm premature rupture of membranes with funisitis compared with those without funisitis (IL-6, 7.5 compared with 2.8 pg/mL, P<.001; G-CSF, 121.7 compared with 56.9 pg/mL, P=.002). Using values identified by the receiver operating characteristic curve, elevated serum IL-6 in the interval 24–72 hours before delivery was significantly associated with funisitis (P<.03), even after controlling for gestational age and insurance status. CONCLUSION: Maternal serum IL-6 and G-CSF appear to be biomarkers in the identification of women with preterm premature rupture of membranes likely to develop funisitis. LEVEL OF EVIDENCE: II

Bacteria Localization and Chorion Thinning among Preterm Premature Rupture of Membranes

Objective Bacterial colonization of the fetal membranes and its role in pathogenesis of membrane rupture is poorly understood. Prior retrospective work revealed chorion layer thinning in preterm premature rupture of membranes (PPROM) subjects. Our objective was to prospectively examine fetal membrane chorion thinning and to correlate to bacterial presence in PPROM, preterm, and term subjects. Study Design Paired membrane samples (membrane rupture and membrane distant) were prospectively collected from: PPROM = 14, preterm labor (PTL = 8), preterm no labor (PTNL = 8), term labor (TL = 10), and term no labor (TNL = 8), subjects. Sections were probed with cytokeratin to identify fetal trophoblast layer of the chorion using immunohistochemistry. Fluorescence in situ hybridization was performed using broad range 16 s ribosomal RNA probe. Images were evaluated, chorion and choriodecidua were measured, and bacterial fluorescence scored. Chorion thinning and bacterial presence were compared among and between groups using Students t-test, linear mixed effect model, and Poisson regression model (SAS Cary, NC). Results In all groups, the fetal chorion cellular layer was thinner at rupture compared to distant site (147.2 vs. 253.7 µm, p<0.0001). Further, chorion thinning was greatest among PPROM subjects compared to all other groups combined, regardless of site sampled [PPROM(114.9) vs. PTL(246.0) vs. PTNL(200.8) vs. TL(217.9) vs. TNL(246.5)]. Bacteria counts were highest among PPROM subjects compared to all other groups regardless of site sampled or histologic infection [PPROM(31) vs. PTL(9) vs. PTNL(7) vs. TL(7) vs. TNL(6)]. Among all subjects at both sites, bacterial counts were inversely correlated with chorion thinning, even excluding histologic chorioamnionitis (p<0.0001 and p = 0.05). Conclusions Fetal chorion was uniformly thinner at rupture site compared to distant sites. In PPROM fetal chorion, we demonstrated pronounced global thinning. Although cause or consequence is uncertain, bacterial presence is greatest and inversely correlated with chorion thinning among PPROM subjects.

Obstetric surgical site infections: 2 grams compared with 3 grams of cefazolin in morbidly obese women

OBJECTIVE: To estimate whether morbidly obese gravid patients were less likely to develop a surgical site infection after receiving a higher dose of preoperative prophylactic antibiotics. METHODS: A retrospective cohort study of morbidly obese pregnant women undergoing cesarean delivery was conducted at two tertiary care centers from 2008 to 2013. Exposure was defined as receiving 2 g compared with 3 g cefazolin preoperatively. Disease was defined by diagnosis of a surgical site infection using Centers for Disease Control and Prevention criteria. We estimated a sample size of 141 patients in each group for a 67% reduction (15% to 5%) in risk for a surgical site infection. RESULTS: There were 335 women included in the cohort with a median absolute weight of 310 (interquartile range 299–333) pounds. Forty-four (13.1%) women were diagnosed with a surgical site infection. There was no difference in surgical site infection among those women who received 2 g compared with 3 g cefazolin (13.1% [23/175] compared with 13.1% [21/160]; P=.996). Labor (crude odds ratio [OR] 2.31, 95% confidence interval [CI] 1.21–4.40), internal labor monitoring (OR 2.78, 1.45–5.31), blood loss greater than 1,500 mL (OR 2.15, 1.09–5.78), and staple closure (OR 2.2, 1.15–4.21) were associated with a surgical site infection among the entire cohort. After multivariable analysis, blood loss greater than 1,500 mL (adjusted OR 3.32, 1.32–8.37) and staple closure (adjusted OR 2.45, 1.19–5.02) remained associated with an increased risk for a surgical site infection, whereas 3 g cefazolin still was not associated with reduced risk for a surgical site infection (adjusted OR 1.33, 0.64–2.74). CONCLUSION: In our multicenter retrospective cohort study, preoperative 3 g cefazolin prophylaxis administered to morbidly obese gravid patients did not reduce surgical site infections. LEVEL OF EVIDENCE: III

β-Arrestin mediates oxytocin receptor signaling, which regulates uterine contractility and cellular migration

Desensitization of the oxytocin receptor (OXTR) in the setting of prolonged oxytocin exposure may lead to dysfunctional labor, which increases the risk for cesarean delivery, and uterine atony, which may result in postpartum hemorrhage. The molecular mechanism for OXTR desensitization is through the agonist-mediated recruitment of the multifunctional protein β-arrestin. In addition to its desensitizing function, β-arrestins have recently been shown to simultaneously activate downstream signaling. We tested whether oxytocin stimulation promotes β-arrestin-mediated OXTR desensitization in vivo and activates β-arrestin-mediated mitogen-activated protein kinase (MAPK) growth signaling. Uterine muscle strips isolated from wild-type mice exhibited diminished uterine contractility following repeated exposure to oxytocin, whereas uterine muscle strips from β-arrestin-1 and β-arrestin-2 knockout mice showed no desensitization. Utilizing siRNA knockdown of β-arrestin-1 and β-arrestin-2 in HEK-293 cells expressing the OXTR, we demonstrated oxytocin-mediated MAPK signaling that was dependent on β-arrestin-1 and β-arrestin-2. Wild-type and β-arrestin-1 and β-arrestin-2 knockout mice receiving intravenous oxytocin also demonstrated oxytocin-mediated MAPK signaling that was dependent on β-arrestin-1 and β-arrestin-2. Finally, to test the significance of β-arrestin-mediated signaling from the OXTR, HEK-293 cells expressing the OXTR showed β-arrestin-dependent proliferation in a cell migration assay following oxytocin treatment. In conclusion, β-arrestin is a multifunctional scaffold protein that mediates both desensitization of the OXTR, leading to decreases in uterine contractility, and MAPK growth signaling following stimulation by oxytocin. The development of unique OXTR ligands that prevent receptor desensitization may be a novel approach in the treatment of adverse clinical events secondary to prolonged oxytocin therapy.

The Influence of Maternal Body Mass Index on Myometrial Oxytocin Receptor Expression in Pregnancy

Obese pregnant women have higher rates of dysfunctional labor patterns, need for oxytocin augmentation, labor induction, postdates pregnancy, and cesarean delivery compared to normal weight pregnant women. We tested the hypothesis that myometrial oxytocin receptor (OXTR) gene and protein expression are affected by obesity in pregnancy. Myometrial samples were obtained at the time of cesarean delivery from the upper aspect of the uterine hysterotomy incision and processed for real-time quantitative polymerase chain reaction and Western blot. There were 63 myometrial samples available for analysis. The median body mass index (BMI) at delivery was 31.0 kg/m2 (interquartile range, 26.0, 40.0 kg/m2), and the median gestational age at delivery was 38.0 weeks (interquartile range, 33.0, 39.1 weeks). The OXTR gene expression did not correlate with maternal BMI at delivery by linear regression, and the median OXTR gene expression did not differ between women with a BMI ≤ 30 kg/m2 and those with a BMI ≥ 40 kg/m2. The OXTR protein expression was also not affected by maternal BMI. Myometrial OXTR gene expression appears to be independent of BMI at the time of delivery. Dysfunctional labor patterns and increased oxytocin utilization seen in obese women may not be due to differences in OXTR expression, though functional studies are required.

Designing Drug Trials: Considerations for Pregnant Women

Clinical pharmacology studies that describe the pharmacokinetics and pharmacodynamics of drugs in pregnant women are critical for informing on the safe and effective use of drugs during pregnancy. That being said, multiple factors have hindered the ability to study drugs in pregnant patients. These include concerns for maternal and fetal safety, ethical considerations, the difficulty in designing appropriate trials to assess the study objectives, and funding limitations. This document summarizes the recommendations of a panel of experts convened by the Division of Microbiology and Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health. These experts were charged with reviewing the issues related to the development of preclinical and clinical drug studies in pregnant women and to develop strategies for addressing these issues. These findings may also be utilized in the development of future drug studies involving pregnant women and their fetus/neonate.

Antibiotic prophylaxis and non-group B streptococcal neonatal sepsis.

OBJECTIVE: To assess the effect of increased use of intravenous penicillin for group B streptococcus (Streptococcus agalactiae, GBS) antibiotic prophylaxis on non-GBS neonatal sepsis and antibiotic resistance. METHODS: We undertook a nonconcurrent cohort study. Microbiology cultures originating from infants with early-onset neonatal sepsis in our neonatal intensive care unit (NICU) from 1992 to 1999 were reviewed. Prevalence of non-GBS neonatal sepsis in the control period (January 1, 1992, through June 30, 1995) was compared with that in the study period (October 1, 1995, through August 31, 1999), when the protocol changed. Chi-squared or Fisher exact tests were used to determine statistical significance. Resistance patterns were compared in similar fashion. RESULTS: The prevalence of non-GBS neonatal sepsis was 1.2 per 1,000 (36 of 31,133) live births before and 1.1 per 1,000 (32 of 28,733) live births after institution of the Centers for Disease Control and Prevention culture-based protocol (P = .97). Our power analysis assumed a doubling in the rate of non-GBS sepsis and required 21,220 live births per arm. Gram-negative and gram-positive sepsis prevalences were not significantly different. Escherichia coli and GBS resistance patterns did not change. CONCLUSION: Institution of a protocol for GBS antibiotic prophylaxis significantly decreased the rate of GBS neonatal sepsis but did not increase the rate of non-GBS neonatal sepsis. Antibiotic resistance patterns of these organisms were not affected. LEVEL OF EVIDENCE: II-2

The Chorion Layer of Fetal Membranes Is Prematurely Destroyed in Women With Preterm Premature Rupture of the Membranes

Preterm premature rupture of the membranes (PPROM) is an important etiology of preterm birth and source of significant neonatal morbidity. We propose that PPROM occurs in the setting of long-standing altered tissue remodeling, which creates a vulnerable environment for the fetal membranes and pregnancy. We tested the hypothesis that PPROM is the result of tissue remodeling in the fetal membranes, specifically the chorion, and this weakening of the chorion compromises the protection provided to the amnion. The purpose of this study was to quantify thickness and apoptosis in the choriodecidua of fetal membranes in patients with PPROM, preterm labor (PTL), preterm no labor (PTNL), and women with term labor (TERM). We conducted a retrospective evaluation of fetal membrane samples from 86 placentas. Immunohistochemistry was performed using a cytokeratin antibody, and mean chorion cellular thickness was compared between each clinical group. To evaluate chorion apoptosis, fetal membranes from patients with PPROM, PTL, and TERM were stained with the M30 antibody, and the degree of cellular apoptosis was determined. Statistical analysis was performed using analysis of variance with corrections for multiple comparisons. The chorion cellular layer was thinner in patients with PPROM compared to patients with PTNL and TERM (62, 140, and 169 µm, respectively, P < .0001), though not significantly different from PTL (95 µm, P > .05). The percentage of apoptotic cells within the chorion among the patients with PPROM was greater compared to PTL and TERM (24.2%, 13.1%, and 8.4%, respectively, P < .001). The chorion cellular layer is thinner and demonstrates increased apoptosis in PPROM compared to patients with PTL, PTNL, and TERM, suggesting differential remodeling between clinical phenotypes.