Tadalafil for Treatment of Fetal Growth Restriction: A Review of Experimental and Clinical Studies

Fetal growth restriction (FGR) is a major concern in perinatal care. Various medications have been proposed as potential treatments for this serious condition. Nonetheless, there is still no definitive treatment. We studied tadalafil, a phosphodiesterase-5 inhibitor, as a therapeutic agent for FGR in clinical studies and animal experiments. In this review, we summarize our preclinical and clinical data on the use of tadalafil for FGR. Our studies in mouse models indicated that tadalafil improved FGR and hypertensive disorders of pregnancy. A phase II trial we conducted provided evidence supporting the efficacy of tadalafil in prolonging pregnancy (52.4 vs. 36.8 days; p = 0.03) and indicated a good safety profile for fetuses and neonates. Fetal, neonatal, and infant mortality was significantly lower in mothers receiving tadalafil treatment than that in controls (total number: 1 vs. 7, respectively; p = 0.03), and no severe adverse maternal events associated with tadalafil were observed. Although further studies are needed to establish the usefulness of tadalafil in FGR treatment, our research indicates that the use of tadalafil in FGR treatment may be a paradigm shift in perinatal care.

Safety and dose-finding trial of tadalafil administered for fetus in labor: A phase I clinical study

AIM

This study aimed to investigate the safety and efficacy of tadalafil in protecting the fetus from hypoxic stress caused by repeated labor pains during delivery and preventing fetal hypoxic-ischemic encephalopathy.

METHODS

The study used a three-case cohort approach. Three patients were administered 10 mg tadalafil and monitored for serious adverse events. In the absence of serious tadalafil-associated adverse events as assessed by the Safety Evaluation Committee, three new patients were added to the study and treated with 20 mg/dose. The blood levels of tadalafil were recorded before and after 2, 4, 8, and 12 h of administration and 2 h after delivery.

RESULTS

A total of seven patients were enrolled, and after excluding one patient who delivered before 37 weeks, tadalafil was administered to six patients. Maternal adverse events were considered acceptable from the maternal perspective, with grade 1 headache, anorexia, and myalgia and no obstetrical complications after delivery at both doses. No serious neonatal adverse events were associated with tadalafil. Tadalafil blood levels remained stable at both doses. In addition, the level of soluble fms-like tyrosine kinase-1 did not alter, while that of the placental growth factor differed significantly before and after tadalafil administration.

CONCLUSIONS

The study confirmed the safety of tadalafil administration during delivery for both mothers and newborns. The stable tadalafil blood levels confirmed the efficacy of the tested administration regime at 12 h interval. These findings would assist in conducting phase II trials to further verify the optimal dose and safety of tadalafil.

Two-dimensional phase-contrast MRI reveals changes in uterine arterial blood flow in pregnant women administered tadalafil for fetal growth restriction

INTRODUCTION

We aimed to examine the effect of uterine arterial (UtA) blood flow changes after tadalafil treatment for fetal growth restriction (FGR) using two-dimensional (2D) phase-contrast magnetic resonance imaging (PC-MRI).

METHODS

We recruited 14 pregnant women with FGR aged 20-44 years, at ≥20 weeks' gestation, between May 2019 and July 2020. They underwent 2D PC-MRI for UtA blood flow measurement 3 days (interquartile range: 2-4) after diagnosis. This group (FGR group) was compared with 14 gestational age (GA)-matched healthy pregnant women (control group). Six patients in the FGR group received treatment with tadalafil administered at 20 mg twice daily after the first MRI until delivery. They underwent a second MRI a week later.

RESULTS

The median total UtA blood/body surface area was 420 mL/min/m2 (290-494) in the FGR group and 547 mL/min/m2 (433-681) in the control group (p = 0.01). Percent increase in blood flow were significantly different between the FGR cases treated with tadalafil and control at 15.8 % (14.3-21.3) and 4.2 % (3.6-8.7), respectively (p = 0.03).

DISCUSSION

UtA blood flow in pregnant women with FGR was significantly lower than that in healthy pregnant women. Tadalafil is expected to improve UtA blood flow, thereby improving placental function in pregnant patients with FGR.

COVID-19 during pregnancy could potentially affect placental function

OBJECTIVE

COVID-19 is an ongoing pandemic and has been extensively studied. However, the effects of COVID-19 during pregnancy, particularly on placental function, have not been verified. In this study, we used blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate whether COVID-19 incidence during pregnancy has any lasting effects with respect to placental oxygenation.

METHODS

This is a case-control study, in which eight cases of singleton pregnancies before 30 weeks gestation with COVID-19 mothers were included. Placental oxygenation was evaluated using BOLD-MRI after 32 weeks of gestation. BOLD-MRI was consecutively performed under normoxia (21% O2), hyperoxia (100% O2), and normoxia for 4 min each. Individual placental time-activity curves were evaluated to calculate the peak score (peakΔR2*) and the time from the start of maternal oxygen administration to the time of peakΔR2* (time to peakΔR2*). Eighteen COVID-19-free normal pregnancies from a previous study were used as the control group.

RESULTS

No significant differences were found between the two groups regarding maternal background, number of days of delivery, birth weight, and placental weight. The parameter peakΔR2* was significantly decreased in the COVID-19 group (8 ± 3 vs. 5 ± 1, p < .001); however, there was no significant difference in time to peakΔR2* (458 ± 74 s vs. 471 ± 33 s, p = .644).

CONCLUSIONS

In this study, BOLD-MRI was used to evaluate placental oxygenation during pregnancy in COVID-19-affected patients. COVID-19 during pregnancy decreased placental oxygenation even post-illness, but had no effect on fetal growth; further investigation of the possible effects of COVID-19 on the fetus and mother is warranted.

Accurate evaluation of the progress of delivery with transperineal ultrasound may improve vaginal delivery: a single-center retrospective study

Although digital examination of the cervix is the standard method used worldwide for evaluating the progress of delivery, it is subjective. Transperineal ultrasound (TPU) is combined with digital evaluation for accurate assessment of fetal descent and rotation of the advanced part of the fetus. This retrospective study aimed to clarify the impact of introducing TPU on perinatal outcomes at Mie University Hospital. We analyzed singleton pregnant women who underwent delivery management at our hospital between April 2020 and March 2021. Perinatal outcomes were compared between patients who used TPU (TPU+ group) and those who did not (TPU- group). The angle of progression and head direction were measured. The rate of vaginal delivery was significantly increased (90.9% vs. 71.6%; P = 0.0017), and the second stage of labor was significantly prolonged in the TPU+ group (148.1 vs. 75.8 min; P < 0.0001). A significant difference was observed in termination in the latent phase between the TPU+ group [3/8 (37.5%) cases] and TPU- group [20/25 (80.0%) cases] (P = 0.036). The rate of vaginal delivery can be increased through accurate evaluation of the progress of delivery with TPU.

Evaluation of fetal acidemia during delivery using the conventional 5-tier classification and Rainbow systems

The association between prepartum time-series fetal heart rate pattern changes and cord blood gas data at delivery was examined using the conventional 5-tier classification and the Rainbow system for 229 female patients who delivered vaginally. They were classified into three groups based on the results of umbilical cord blood gas analysis at delivery. The fetal heart rate pattern classifications were based on analysis of measurement taken at 10-min intervals, beginning at 120 min pre-delivery. The relationship between fetal heart rate pattern classification and cord blood pH at delivery changed over time. The 5-tier classification at each interval increased before delivery in the Mild and Severe groups compared with the Normal group. No significant differences were observed between acidemia groups. The Rainbow classification showed a significant differences between the acidemia groups at each interval, particularly during the prepartum period. A relationship between classification and outcome was evident before delivery for both the 5-tier classification and Rainbow system.

Characterization of a half-wave plate for cosmic microwave background circular polarization measurement with POLARBEAR

A half-wave plate (HWP) is often used as a modulator to suppress systematic error in the measurements of cosmic microwave background (CMB) polarization. A HWP can also be used to measure circular polarization (CP) through its optical leakage from CP to linear polarization. The CP of the CMB is predicted from various sources, such as interactions in the Universe and extension of the standard model. Interaction with supernova remnants of population III stars is one of the brightest CP sources. Thus, the observation of the CP of CMB is a new tool for searching for population III stars. In this paper, we demonstrate the improved measurement of the leakage coefficient using the transmission measurement of an actual HWP in the laboratory. We measured the transmittance of linearly polarized light through the HWP used in Polarbear in the frequency range of 120-160 GHz. We evaluate the properties of the HWP by fitting the data with a physical model using the Markov Chain Monte Carlo method. We then estimate the band-averaged CP leakage coefficient using the physical model. We find that the leakage coefficient strongly depends on the spectra of CP sources. We thus calculate the maximum fractional leakage coefficient from CP to linear polarization as 0.133 ± 0.009 in the Rayleigh-Jeans spectrum. The nonzero value shows that Polarbear has a sensitivity to CP. Additionally, because we use the bandpass of detectors installed in the telescope to calculate the band-averaged values, we also consider systematic effects in the experiment.

Surgical technique for fertility preservation for placenta accreta spectrum without previa: Tourniquet, uterus inversion and placental dissection procedure

The placenta accreta spectrum without previa is difficult to diagnose before delivery and sometimes requires hysterectomy. A fertility preservation procedure is useful when placenta accreta spectrum is unexpectedly encountered. A 38-year-old woman, conceived by in vitro fertilization (IVF), was not diagnosed of placenta accreta spectrum until delivery. A cesarean section was performed for fetal breech presentation. The placenta could not be detached from the uterine fundus and marked bleeding started. We conducted the "TURIP" procedure: ensured hemostasis with tourniquet of uterine isthmus, uterus inversion to expose the adhesion site with intra-venous nitroglycerin administration, placental detachment by sharp dissection under direct visualization. The detached areas were sutured for hemostasis. The patient recovered uneventfully and achieved the second pregnancy by IVF 1 year later. The TURIP procedure is useful to preserve fertility in unpredicted placenta accreta spectrum without previa, even in undiagnosed cases before delivery.

Fetal Biometric Assessment and Infant Developmental Prognosis of the Tadalafil Treatment for Fetal Growth Restriction

Background and Objectives: Tadalafil is expected to treat fetal growth restriction (FGR), a risk factor for stillbirth and neonatal morbidity. This study aimed to evaluate the fetal biometric growth pattern of fetuses with FGR treated with tadalafil by ultrasonographic assessment. Materials and Methods: This was a retrospective study. Fifty fetuses diagnosed with FGR and treated by maternal administration of tadalafil and ten controls who received conventional treatment at Mie University Hospital from 2015 to 2019 were assessed. Fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), and estimated fetal weight (EFW) at the start of treatment and at two weeks and four weeks of treatment were mainly assessed by ultrasound examination. The Wilcoxon signed-rank test was used to assess the measures. The Kyoto Scale of Psychological Development (KSPD) was used to assess the developmental prognosis on tadalafil-treated children at 1.5 years of corrected age (CA) and 3 years old. Results: The median gestational age at the start of treatment was 30 and 31 weeks in the tadalafil and control groups, respectively, and the median gestational age at delivery was 37 weeks in both groups. The Z-score of HC was significantly increased at 4 weeks of treatment (p = 0.005), and the umbilical artery resistance index was significantly decreased (p = 0.049), while no significant difference was observed in the control group. The number of cases with an abnormal score of less than 70 on the KSPD test was 19% for P-M, 8% for C-A, 19% for L-S, and 11% for total area at 1.5 years CA. At 3 years old, the respective scores were 16%, 21%, 16%, and 16%. Conclusions: Tadalafil treatment for FGR may maintain fetal HC growth and infants' neuro-developmental prognosis.

Comparative study of the usefulness of risk score assessment in the early stages of COVID ‐19 affected pregnancies: Omicron variant versus previous variants

Aim

To evaluate the utility of the risk score in assessing the current status and prognosis of COVID‐19 in pregnancy.

Methods

Seventy‐seven cases affected before the Omicron variant epidemic and 50 pregnant cases affected by the Omicron variant were included. The risk score consists of maternal background, current condition, and examination findings. We determined the risk score in the early stages of disease onset.

Results

There were no significant differences in the maternal or gestational ages between the groups. The risk score was significantly lower in the After‐Group patients (those affected during the Omicron epoch), while 14.3% of the Before‐Group patients (those affected during the pre‐Delta and Delta epochs), experienced a worsening of disease after the visit to the center, whereas none of the After‐Group patients did. The Before Group's frequency of risk score items was higher among the two groups for “fever for ≥48 h,” “mild pneumonia image,” and “blood tests,” whereas “disease onset 14 days after the second vaccination” was increased in After Group. The blood test parameters for platelet count, C‐reactive protein, and D‐dimer levels were not significantly different between the groups.

Conclusions

The risk score system appeared superior in detecting deteriorating cases. There were no cases of post‐illness deterioration in the After‐Group, suggesting that cases of the Omicron variant in pregnancy may have had a less severe course compared to that of previous variants. However, there was no significant difference between the groups in terms of a specific blood test evaluation, suggesting the need for a combined evaluation of cases affected during pregnancy.

Evaluation of the tolerability of monoclonal antibody therapy for pregnant patients with COVID-19

Aim

To evaluate the tolerability of casirivimab and imdevimab (CAS/IMB) therapy in pregnant women with COVID‐19 in Japan and its impact on the neonate and process of delivery.

Methods

Eight cases of pregnancy complicated by COVID‐19 and requiring hospitalization during the delta variant epidemic were included. Gestational age, initial symptoms, pregnancy complications and outcome, severity of illness, blood test findings at the time of treatment initiation and on days 3–5 after administration, body temperature at administration, and 8, 24, and 48 h post‐administration, delivery outcome, and neonatal findings were recorded. Ten pregnant women who required hospitalization at the same time and did not receive CAS/IMB were used as controls.

Results

Of the eight cases, seven were mild, and one case was of moderate severity. Body temperature in the CAS/IMB group was significantly higher at 8 h post‐administration than that at the time of administration. However, body temperature significantly reduced at 24 and 48 h post‐administration in the CAS/IMB group compared with that in the control group. There were no apparent adverse events after CAS/IMB administration.

Conclusions

Maternal administration of CAS/IMB was safe. Although it was difficult to evaluate the improvement in disease by blood test findings, the fever improved within 24 h, which suggests rapid improvement in patient condition.

Predicting Preeclampsia Pregnancy Termination Time Using sFlt-1

Background

The aim of this study was to determine the usefulness of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in predicting the time for pregnancy termination in pregnant women with known preeclampsia (PE) onset.

Methods

Forty-four pregnant women diagnosed with PE (22 weeks 0 days to 33 weeks 6 days gestation) were included in this study. The levels of sFlt-1 and PlGF, and the sFlt-1/PlGF ratio were compared between the women that delivered in <24 h (T group) and those that delivered in more than 24 h (P group), and between women that delivered in <1 week (T group) and those that delivered in more than 1 week (P group). Cutoff values were calculated for the three markers that were the most significantly correlated with predicting pregnancy termination at <24 h and <1 week.

Results

Among sFlt-1, PlGF, and sFlt-1/PlGF, sFlt-1 was the most significantly associated with the timing of pregnancy termination. sFlt-1 cutoff values of 8682.1 pg/ml (AUC 0.71; 95%Cl, 0.5191–0.9052) and 7,394.5 pg/ml (AUC 0.78; 0.78, 95%Cl, 0.6394–0.9206) for delivery in <24 h and delivery within 1 week, respectively, were important predictive values. The positive predictive value for delivery within 24 h was 43.9%, with a sensitivity of 72.3% and specificity of 69.0%, when sFlt−1 was <8,682 pg/ml. A sFlt-1 level of 7,394 pg/ml or greater would result in delivery within 1 week, with a positive predictive value of 67.2%; the sensitivity was 79.0% and specificity was 72.0%.

Conclusion

This study showed that sFlt-1 may be effective in predicting the timing of pregnancy termination. However, the number of cases was small and, thus, the results were not definitive. This finding should be researched further in order to predict the optimal timing of pregnancy termination in PE to reduce severe maternal complications.

Tadalafil treatment for fetuses with early-onset growth restriction: a protocol for a multicentre, randomised, placebo-controlled, double-blind phase II trial (TADAFER IIb)

INTRODUCTION

TheTADAlafil treatment for Fetuses with early-onset growth Restriction: multicentrer, randomizsed, phase II trial (TADAFER II) study showed the possibility of prolonging the pregnancy period in cases of early-onset fetal growth restriction; however, it was an open-label study. To establish further evidence for the efficacy of tadalafil in this setting, we planned a multicentre, randomised, placebo-controlled, double-blind trial.

METHODS AND ANALYSIS

This trial will be conducted in 180 fetuses with fetal growth restriction enrolled from medical centres in Japan; their mothers will be randomised into three groups: arm A, receiving two times per day placebo; arm B, receiving one time per day 20 mg tadalafil and one time per day placebo and arm C, receiving 20 mg two times per day tadalafil. The primary endpoint is the prolongation of gestational age at birth, defined as days from the first day of the protocol-defined treatment to birth. To minimise bias in terms of fetal baseline conditions and timing of delivery, a fetal indication for delivery as in TADAFER II will be established in this trial. The investigator will evaluate fetal baseline conditions at enrolment and decide the timing of delivery based on this indication.

ETHICS AND DISSEMINATION

This study has been approved by Mie University Hospital Clinical Research Review Board on 22 July 2019 (S2018-007). Written informed consent will be obtained from all mothers before recruitment. Our findings will be widely disseminated through peer-reviewed publications.

TRIAL REGISTRATION

jRCTs041190065.

Placental growth factor level is correlated with intrapartum fetal heart rate findings

Objective

Here, we tested the correlation between maternal placental growth factor (PlGF) and fetal heart rate (FHR) monitoring findings.

Methods

We included 35 women with single pregnancies from 35 to 42 weeks of gestation who were hospitalized owing to onset of labor. Blood samples were collected at the start of labor. Intrapartum FHR monitoring parameters included total deceleration area, average deceleration area (mean deceleration area per 10 min), and five-tier classification level.

Results

Of the 35 women, 26 (74%) had vaginal delivery and 9 (26%) had cesarean section. After excluding 2 women who had cesarean section for arrest of labor, we analyzed 26 women who had vaginal delivery (VD group) and 7 who had cesarean section for fetal indications (CSF group). PlGF level was significantly higher in the VD group (157 ± 106 pg/ml) than in the CSF group (74 ± 62 pg/ml) (P = 0.03). There were no significant correlations between PlGF and total (r = -0.07) or average (r = -0.08) deceleration area.　There was a significant negative correlation (r = -0.42, P = 0.01) between PlGF and the percentage of level 3 or higher in the five-level classification.

Conclusion

PlGF was correlated with FHR monitoring findings and might be a promising biomarker of intrapartum fetal function.

Appropriate Method of Administering Vasopressors for Maternal Hypotension Associated with Combined Spinal Epidural Anesthesia in Elective Cesarean Section: Impact on Postnatal Respiratory Support for Newborns

Background and Objectives: Vasopressors are used for treating maternal hypotension. However, the appropriate administration method and effects on newborns have not been reported. We evaluated maternal blood pressure fluctuation and neonatal findings in patients who received continuous vasopressor administration during elective cesarean sections and those who received bolus vasopressor administration upon onset of hypotension. Materials and Methods: We retrospectively analyzed the data of 220 patients scheduled for elective cesarean delivery under spinal anesthesia at Mie University Hospital between April 2017 and March 2021. The patients were classified according to the method of vasopressor administration. Maternal information, intraoperative maternal blood pressure fluctuation, and neonatal findings were examined. A multiple regression analysis was performed for the administration of postpartum neonatal respiratory support using maternal background information and other variables related to blood pressure changes as independent variables. Results: The Continuous group and the Bolus group were composed of 98 and 122 patients, respectively. No difference was observed in maternal background information between the groups. Significant changes were noted in several blood pressure parameters between both groups. As for neonatal parameters, newborns of Bolus group patients had lower pO2, 1 min and 5 min Apgar scores, and required more respiratory support than those of Continuous group patients. In the multiple regression analysis, the groups and maternal post-anesthesia diastolic blood pressure variability were considered explanatory variables. Conclusions: Maternal hypotension and the need for neonatal respiratory support associated with anesthesia administration in elective cesarean section may be improved by continuous vasopressor administration upon induction of combined spinal–epidural anesthesia.

Maternal blood concentration of tadalafil in pregnancy: Comparison of pregnant and non-pregnant women

OBJECTIVE

In this study, the drug kinetics of tadalafil were compared between pregnant and non-pregnant women to determine the ideal dosage to promote uterine blood flow.

MATERIALS AND METHODS

We recruited five pregnant and five non-pregnant women, all of which were administered tadalafil (20 mg/day). The blood concentration of tadalafil was measured 1, 2, 4, 6, 8, and 24 h after administration. We investigated the side effects within 4 days of tadalafil administration and compared the cumulative frequency between the two groups.

RESULTS

The mean area under the concentration-time curve and maximum blood concentration of tadalafil were not different between the pregnant and non-pregnant groups. Time to maximum blood concentration was delayed by 1 min on average in the pregnant group compared with the non-pregnant group. The cumulative frequency of side effects was significantly lower in the pregnant group than in the non-pregnant group (P = 0.026). No side effects were observed in either group after the fifth day of the tadalafil administration.

CONCLUSION

Although there was no difference in maximum blood concentration between non-pregnant and pregnant women, the rate of side effects was lower in pregnant women than in non-pregnant women. Therefore, pregnant women may tolerate tadalafil better.

Tadalafil Treatment of Mice with Fetal Growth Restriction and Preeclampsia Improves Placental mTOR Signaling

Fetal growth restriction (FGR) is a major cause of poor perinatal outcomes. Although several studies have been conducted to improve the prognosis of FGR in infants, no effective intrauterine treatment method has been established. This study aimed to use tadalafil, a phosphodiesterase 5 inhibitor (PDE5) inhibitor, as a novel intrauterine treatment and conducted several basic and clinical studies. The study investigated the effects of tadalafil on placental mTOR signaling. Tadalafil was administered to mice with L-NG-nitroarginine methyl ester (L-NAME)-induced FGR and associated preeclampsia (PE). Placental phosphorylated mTOR (p-mTOR) signaling was assessed by fluorescent immunohistochemical staining and Western blotting. The expression of p-mTOR was significantly decreased in mice with FGR on 13 days post coitum (d.p.c.) but recovered to the same level as that of the control on 17 d.p.c. following tadalafil treatment. The results were similar for 4E-binding protein 1 (4E-BP1) and S6 ribosomal (S6R) protein, which act downstream in the mTOR signaling pathway. We demonstrate that the tadalafil treatment of FGR in mice improved placental mTOR signaling to facilitate fetal growth. Our study provides the key mechanistic detail about the mode of action of tadalafil and thus would be helpful for future clinical studies on FGR.

Assessment of the value of measuring soluble fms-like tyrosine kinase-1 and placental growth factor levels following administration of tadalafil to treat fetal growth restriction

PURPOSE

The aim of this study was to measure the blood levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) before and after tadalafil treatment in patients with fetal growth restriction.

MATERIALS AND METHODS

Maternal blood was collected from 13 women before and 2 weeks after tadalafil administration in the TADAFER II trial. The tadalafil treatment was conducted in addition to the conventional FGR treatment. As a control, maternal blood was also collected from 11 women before and 2 weeks after conventional treatment for fetal growth restriction. Blood sFlt-1 and PlGF were measured and the sFlt-1/PlGF ratio was calculated. Student's t-test was used to statistically analyze differences in the sFlt-1 and PlGF levels, and in the sFlt-1/PlGF ratios.

RESULTS

In both treatment groups, the levels of sFlt-1 and PlGF before and after treatment were not significantly different from each other. The sFlt-1/PlGF ratio was 2.0 ± 1.0 before and 17.6 ± 11.3 after treatment in the control group (p=.04). The sFlt-1/PlGF ratio was 2.2 ± 1.1 before and 22.2 ± 10.6 after tadalafil treatment in the tadalafil group (p=.06). The sFlt-1/PlGF ratios before and after tadalafil treatment were significantly increased in the control group. In both treatment groups, the sFlt-1/PlGF ratios before and after treatment were less than 38.

CONCLUSIONS

We conclude that the levels of sFlt-1 and PlGF were not significantly different as a result of tadalafil treatment. Further studies are needed to understand the mechanism of action of tadalafil in the treatment of fetal growth restriction.

Comparison of perinatal outcomes between controlled-release dinoprostone vaginal delivery system (PROPESS) and metreurynter for cervical ripening in labor induction: A retrospective single-center study in Japan

AIM

This study aimed to compare the efficacy and safety of a controlled-release dinoprostone vaginal delivery system (PROPESS) and a metreurynter for labor induction.

METHODS

This retrospective case-controlled study included 117 pregnant women (51 and 66 in the PROPESS and metreurynter groups, respectively) who required labor induction after >37 weeks' gestation at Mie University Hospital between January 2018 and September 2020. The primary outcome was the success rate of vaginal delivery. The secondary outcomes were changes in the Bishop score from the first insertion of PROPESS or the metreurynter to removal, uterine hyperstimulation and non-reassuring fetal status during the first insertion, proportion of pregnant women who needed pre-delivery oxytocin after removal, time to vaginal delivery after the first insertion, proportion of pregnant women who delivered vaginally within 12 or 24 h after the first insertion, and neonatal outcomes.

RESULTS

The proportion of pregnant women, especially primiparas, who delivered vaginally was significantly higher in the PROPESS group (26/34 [76.5%]) than in the metreurynter group (25/52 [48.1%]; p = 0.01). Moreover, among multiparas in the PROPESS group who delivered vaginally, nine (56.3%) out of 16 women delivered vaginally within 3 h of labor onset.

CONCLUSIONS

PROPESS for cervical ripening may reduce the risk of undergoing cesarean section in pregnant women requiring labor induction, especially primiparas. It is important to consider the possibility of precipitate labor when using the PROPESS in multiparas.

Reference range for C1-esterase inhibitor (C1 INH) in the third trimester of pregnancy

OBJECTIVES

The objectives of this study were to (i) establish the reference range and mean value for normal levels of C1-esterase inhibitor (C1 INH) during pregnancy, and (ii) investigate the association between C1 INH and uterine atony, as measured by blood loss at delivery.

METHODS

We prospectively studied 200 healthy pregnant women who were registered. We studied C1 INH levels in 188 women at 34 and 35 gestational weeks of pregnancy. The reference range for C1 INH during the third trimester of pregnancy was calculated using the value of C1 INH that was determined at registration.

RESULTS

The mean value of C1 INH was determined to be 70.3% (95% confidence interval, 68.7-71.9). While the C1 INH levels in four women were determined to be 40% lower than the calculated mean value, amniotic fluid embolism (AFE) did not occur in any of the women studied.

CONCLUSIONS

This study successfully demonstrated that a reference value for C1 INH activity can be established using the methods described herein. Further research is needed to determine whether C1 INH is involved in obstetric coagulopathy syndrome such as amniotic fluid embolism.

Pulmonary thromboembolism during pregnancy and puerperium: Comparison of survival and death cases

AIM

In Japan, the frequency of maternal deaths due to obstetric hemorrhage has been decreasing in the last decade, while that resulting from other causes such as pulmonary thromboembolism (PTE) was consistent. To help reduce maternal deaths due to PTE, we investigated PTE during pregnancy and puerperium and compared the survival and death cases, and aimed to find out life and death factors.

METHODS

This study was a retrospective analysis based on a clinical chart review in 407 maternal and perinatal centers. We compared the survival and death cases of PTE during pregnancy and puerperium from 2013 to 2017.

RESULTS

In PTE during pregnancy, the survival cases underwent significantly earlier diagnoses than the death cases, and thromboprophylaxis was performed in most of both the survival and death cases of PTE during puerperium according to the existing Japanese guidelines; however, only one fourth of the total cases underwent anticoagulation to prevent venous thromboembolism (VTE).

CONCLUSIONS

Early diagnosis of PTE in suspected cases was associated with better survival during pregnancy.

sFlt-1 value predicts pregnancy prolongation periods from diagnosis in pregnant women diagnosed with early-onset preeclampsia

PURPOSE

The aim of this study is to analyze whether soluble fms-like tyrosine kinase-1 (sFlt-1) can be correlated with the severity of PE.

MATERIALS AND METHODS

This study was conducted in a single hospital and is a prospective, observational study. sFlt-1 was measured at the diagnosis of preeclampsia. The period from diagnosis to pregnancy termination (pregnancy prolongation periods) was defined as the barometer for the severity of PE. The correlations between sFlt-1 level with pregnancy prolongation periods were then analyzed.

RESULTS

Eighteen pregnant women diagnosed with early-onset preeclampsia were recruited. sFlit-1 value significantly negatively correlated with the pregnancy prolongation period from diagnosis (p = .003, R = 0.647).

CONCLUSION

sFlt-1 was correlated with the pregnancy prolongation periods after onset of PE. sFlt-1 in early-onset PE may reflect the severity of PE in pregnant women.

Characteristics and influence of Mycoplasma/Ureaplasma cultures in amniotic fluid on perinatal outcomes

AIM

To investigate the effects of Mycoplasma/Ureaplasma cultured in amniotic fluid on perinatal characteristics in preterm delivery between 22 and 33 weeks of gestation.

METHODS

The study was conducted in a tertiary perinatal center and involved 38 pregnant women who had undergone amniocentesis to evaluate intrauterine infection due to preterm labor or premature rupture of membranes. The subjects were divided into three groups based on the culture results: negative (Negative Group, n = 24), positive for Mycoplasma/Ureaplasma (M/U Group, n = 6), and positive for other pathogens (Other Pathogens Group, n = 8). One-way analysis of variance was used to compare the three groups.

RESULTS

The incidence of histological chorioamnionitis and neonatal sepsis was significantly different among the three groups (the Negative Group and the Other Pathogens Group, P < 0.01; the M/U Group and the Other Pathogens Group, P = 0.03). In the M/U Group, no infants had sepsis, severe intraventricular hemorrhage, cystic periventricular leukomalacia, or poor neurological outcomes, but one infant developed bronchopulmonary dysplasia and needed home oxygen treatment. Although one died of gastrorrhexis, the remaining five patients had normal brain magnetic resonance imaging findings and developed normally.

CONCLUSION

The presence of Mycoplasma/Ureaplasma isolated from amniotic fluid did not cause neonatal sepsis or poor prognosis. In some infants, there was no histological chorioamnionitis in the placenta. These pathogens thus seem to be less invasive than any other microbes with respect to perinatal outcomes.

Erratum to: Seasonal trend and clinical presentation of Bacillus cereus bloodstream infection: association with summer and indwelling catheter

Bacillus cereus, an opportunistic pathogen, can cause fatal infection. However, B. cereus bloodstream infections (BSIs) have not been well characterised. From 2008 to 2013, B. cereus isolates from all of the specimens and patients with B. cereus BSIs were identified. Environmental samples were collected to detect B. cereus contamination. We also characterised the clinical presentation of B. cereus BSI through analyses of risk factors for BSI and mortality. A total of 143 clinical B. cereus isolates was detected. Fifty-one patients with nosocomial infections were diagnosed as B. cereus BSI, and 37 had contaminated blood cultures. The number of B. cereus isolates and BSI patients was significantly greater from June to September than from January to April (3.4 vs. 1.0 per month and 1.4 vs. 0.2, respectively). All BSIs were nosocomial and related to central or peripheral vascular catheter. Urinary catheter [odds ratio (OR) 6.93, 95 % confidence interval (CI) 2.40-20.0] was the independent risk factor associated with BSI patients when compared to patients regarded as contaminated. In-hospital mortality among BSI patients was 20 % and was associated with urinary catheter (OR 12.3, 95 % CI 0.67-225, p=0.045) and higher Charlson index (OR 1.99, 95 % CI 1.26-3.12). The number of B. cereus isolates and BSI increased during summer. Inpatients with indwelling vascular or urinary catheters should be carefully monitored for potential B. cereus BSIs.

Quality-of-life outcomes from a randomized phase III trial of dose-dense weekly paclitaxel and carboplatin compared with conventional paclitaxel and carboplatin as a first-line treatment for stage II-IV ovarian cancer: Japanese Gynecologic Oncology Group Trial (JGOG3016)

BACKGROUND

Dose-dense weekly paclitaxel (Taxol) and carboplatin (dd-TC) improved survival compared with conventional tri-weekly paclitaxel and carboplatin (c-TC) as a first-line chemotherapy for newly diagnosed stage II-IV ovarian cancer in the Japanese Gynecologic Oncology Group 3016 trial. We report the quality-of-life (QoL) results from this trial.

PATIENTS AND METHODS

A total of 637 patients were randomly assigned to receive c-TC or dd-TC (c-TC, n = 319; dd-TC, n = 312) and were asked to complete a QoL assessment at baseline, just after the third and sixth chemotherapy cycles, and at 12 months after randomization. QoL was assessed using Functional Assessment of Cancer Therapy (FACT)-general (FACT-G), FACT-taxane subscale (FACT-T), and FACT-ovary subscale (FACT-Ov). The overall QoL and that according to each subscale were analyzed using mixed-effects models adjusted for treatment and time.

RESULTS

Baseline QoL assessment was completed by 204 out of 319 (63.9%) and 200 out of 312 (64.1%) patients in the c-TC and dd-TC groups, respectively. In these groups, the compliance rates with regard to QoL assessment were 74.5% and 73.0%, respectively, after three chemotherapy cycles; 86.8% and 86.9%, respectively, after six chemotherapy cycles; and 74.2% and 71.6%, respectively, at 12 months after randomization. The overall QoL did not differ significantly between the two treatment groups up to 12 months after randomization (P = 0.46). However, QoL according to the FACT-T subscale was significantly lower in the dd-TC group than in the c-TC group (P = 0.02).

CONCLUSION

dd-TC does not decrease overall QoL compared with c-TC.

Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Regional dissemination of Acinetobacter species harbouring metallo-β-lactamase genes in Japan

Metallo-β-lactamase (MBL) producers have been reported among the various Acinetobacter species worldwide. In this study, the epidemiology and molecular characteristics of carbapenemase-encoding genes and mobile elements were studied to analyse the regional dissemination of MBL genes in Acinetobacter species. From January 2001 to December 2006, 48 Acinetobacter isolates harbouring MBL genes identified from five hospitals in Kyoto and Shiga Prefecture, Japan were collected and analysed. The partial rpoB gene or the 16S-23S ribosomal RNA intergenic spacer region was sequenced to obtain a species-level identification. Molecular typing using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) was performed. Twenty-five Acinetobacter pittii isolates were divided into eight PFGE types and five sequence types (STs) using MLST. Nine Acinetobacter bereziniae isolates belonged to five PFGE types. Five Acinetobacter nosocomialis isolates were divided into two PFGE types and two STs. Three unclassified Acinetobacter species isolates were divided into two PFGE types. Eighteen of the 25 A. pittii isolates belonged to ST119 and were identified from four hospitals. The bla(IMP-19) gene was detected in 41 of 48 isolates, including all of the A. pittii ST119 isolates. The bla(IMP-1) and bla(IMP-11) genes were detected in four and three isolates, respectively. The MBL genes were all embedded within a class 1 integron as a gene cassette array: bla(IMP-19) -aac(6')-31-bla(OXA-21) -aadA1, catB8-like/aacA4-bla(IMP-1) and bla(IMP-11). This study is the first report demonstrating the regional dissemination of MBL-producing Acinetobacter species. A. pittii ST119 harbouring blaIMP-19 was widely spread throughout the Kyoto-Shiga region.

The outcome of Japanese anorexia nervosa patients treated with an inpatient therapy in an internal medicine unit

OBJECTIVE

To investigate the outcome of Japanese anorexia nervosa (AN) patients who were treated with the standard Japanese inpatient therapy.

METHOD

Of the 88 female AN patients treated with our inpatient therapy between January 1997 and December 2002, 67 (76.1%) who agreed to cooperate in this study were assessed by the Global Clinical Score (GCS) at admission and follow-up, 6.3±1.8 years after discharge. Their clinical characteristics at admission and discharge were also examined.

RESULTS

Four (6.0%) patients had died before follow-up. BMI was significantly increased during inpatient therapy. At follow-up, excellent, much improved, symptomatic, and poor outcomes on GCS were 57.1%, 14.3%, 14.3% and 14.3%, respectively. Younger age at admission and larger BMI at discharge were significantly associated with a better outcome.

DISCUSSION

This study shows the potential for the use of this method for the treatment of AN patients in countries without specialized eating disorder units.

Molecular and clinical characterization of plasmid-mediated AmpC β-lactamase-producing Escherichia coli bacteraemia: a comparison with extended-spectrum β-lactamase-producing and non-resistant E. coli bacteraemia

Plasmid-mediated AmpC β-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case-control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone.

Regional spread and control of vancomycin-resistant Enterococcus faecium and Enterococcus faecalis in Kyoto, Japan

The purpose of this investigation was to control the post-outbreak prevalence of vancomycin-resistant enterococci (VRE) in the affected Kyoto region. The study period was from 2005 to 2010. Faecal samples were subjected to VRE screening, and vancomycin resistance genes were detected by polymerase chain reaction (PCR). The genotype was determined by pulsed-field gel electrophoresis (PFGE) of genomic DNA digested with SmaI and by multilocus sequence typing (MLST). A VRE control programme was established in 2006, consisting of a laboratory-based faecal VRE screening system, annual surveillance of hospital inpatients and the promotion of adequate infection control measures. vanA-Enterococcus faecium, vanB-E. faecium and vanB-E. faecalis were detected at 35, 12 and 5 hospitals, respectively. Genotype analysis revealed that all of the vancomycin-resistant E. faecium isolates obtained since 2005 belonged to ST78, and that clonally related vanB-E. faecalis of ST64 had spread to three hospitals. The rate of faecal VRE carriage among the patients enrolled in the annual surveillance increased until 2007, when it reached 24 (1.2%) of the 2,035 enrolled patients. The rate began to decrease in 2008 and, by 2010, reached a low of 4 (0.17%) of the 2,408 enrolled patients. While VRE did spread within the Kyoto region, the VRE control programme succeeded in controlling the overall VRE spread.

Control of an outbreak of carbapenem-resistant Pseudomonas aeruginosa in a haemato-oncology unit

An outbreak of a multidrug-resistant Pseudomonas aeruginosa producing metallo-β-lactamase (MBLPA) in a haemato-oncology unit was controlled using multidisciplinary interventions. The present study assesses the effects of these interventions by active surveillance of the incidence of MBLPA infection at the 1,240-bed tertiary care Kyoto University Hospital in Kyoto, Japan. Infection control strategies in 2004 included strengthening contact precautions, analysis of risk factors for MBLPA infection and cessation of urine collection. However, new MBLPA infections were identified in 2006, which prompted enhanced environmental cleaning, routine active surveillance, and restricting carbapenem usage. Between 2004 and 2010, 17 patients in the unit became infected with indistinguishable MBLPA strains. The final five infected patients were found by routine active surveillance, but horizontal transmission was undetectable. The MBLPA outbreak in the haemato-oncology unit was finally contained in 2008.

Close cooperation between infectious disease physicians and attending physicians can result in better management and outcome for patients with Staphylococcus aureus bacteraemia

Staphylococcus aureus bacteraemia (SAB) is a serious infection that demands prompt clinical attention for good outcome. To assess the impact of intervention by infectious diseases physicians (IDPs) in cases with SAB, a retrospective cohort study of patients with SAB was performed in a 1240-bed, university hospital in Japan, with the aim of comparing the management and outcome of patients during the initial and the latter half of the intervention period,. Three hundred and forty-six patients with SAB during the 7-year period, from 2002 to 2008, were included, and 194 patients in the initial half of the period (from 2002 to 2005) were compared with 152 patients in the later period (from 2006 to 2008). There was no significant difference between the two groups with respect to patient's clinical background, although more patients in the later period were receiving immunosuppressive treatment. The proportion of methicillin resistant S. aureus was lower during the later period (56.2% vs. 43.3%; p 0.02). Echocardiography was used more frequently (37.1% vs. 64.5%; p < 0.001). Infective endocarditis and metastatic infections were diagnosed more frequently (10.8% vs. 20.4%; p 0.01). Follow-up blood cultures were obtained more regularly (52.1% vs. 73.7%; p <0.001) and therapy was more frequently administered for at least 14 days (47.4% vs. 82.2%; p <0.001). The 30-day mortality improved during the intervention period (25.8% vs. 16.4%; p 0.04). The total number of blood cultures received by the laboratory increased annually and the total number of consultations increased by approximately 1.6-fold compared to 2002. Proactive intervention by IDPs raised awareness of optimal management of bacteraemia and improved the adherence to the standards of care, which subsequently resulted in an improvement in the outcome.

Predictors of menstrual resumption by patients with anorexia nervosa

OBJECTIVE

To investigate which factors predict the resumption of menstruation by patients with anorexia nervosa (AN).

METHODS

Participants were AN patients who, even after weight recovery by inpatient treatment, had prolonged amenorrhea (N=11), AN patients who resumed menstruation after weight recovery (N=9), and age-matched healthy controls (N=12). Anthropometric data and the serum levels of leptin, insulin-like growth factor I (IGF-1), cortisol, luteinizing hormone (LH), estradiol (E2), and other hormones were measured at the beginning of the inpatient treatment and after weight recovery.

RESULTS

Of the baseline anthropometric and hormonal factors, logistic regression analysis extracted a high serum cortisol level as a predictor of the inhibition of the resumption of menstruation. After weight recovery, the E2 and leptin levels were significantly higher for eumenorrheic patients than for amenorrheic patients.

CONCLUSION

The baseline serum cortisol level was a predictor of the prolonged inhibition of menstrual recovery.

Pretransplant serum ferritin and C-reactive protein as predictive factors for early bacterial infection after allogeneic hematopoietic cell transplantation

Although fluoroquinolones or other antibiotics are commonly used to prevent bacterial infections after hematopoietic cell transplantation (HCT), because of the growing presence of multidrug-resistant microorganisms, it is important to identify patients who are more likely to benefit from antibacterial prophylaxis. To evaluate risk factors for early bacterial infection after allogeneic HCT, we retrospectively analyzed clinical data for 112 consecutive adult patients with hematological malignancies who received transplants without any antibacterial prophylaxis. The cumulative incidence of bacterial infection at 30 days after transplantation was 16%. Among various pre-transplant factors, only high serum ferritin (>700 ng/mL, 47 patients) and high C-reactive protein (CRP) (>0.3 mg/dL, 28 patients) levels were significantly associated with the development of bacterial infection in a multivariate analysis (hazard ratio (95% confidence interval): ferritin, 4.00 (1.32-12.17); CRP, 3.64 (1.44-9.20)). In addition, septic shock and sepsis with organ failure were exclusively observed in patients who had high ferritin and/or high CRP levels. These results suggest that pretransplant serum ferritin and CRP levels can be useful markers for predicting the risk of early bacterial infection after allogeneic HCT. It may be prudent to limit antibacterial prophylaxis to patients with predefined risk factors to ensure the safety of HCT with the use of fewer antibiotics.

High prevalence of mutators among Enterobacter cloacae nosocomial isolates and their association with antimicrobial resistance and repetitive detection

We determined the mutation frequencies of 59 nosocomial isolates of Enterobacter cloacae, and investigated their association with antimicrobial susceptibility, genotype, and history of exposure to antimicrobials. The frequencies of mutations leading to rifampicin resistance ranged from 5.8 × 10(-9) to 8.0 × 10(-6) (median, 5.0 × 10(-8)). Seven of the 59 (12%) isolates were graded as strong mutators exhibiting a more than 50-fold increase in the mutation frequency relative to that of E. cloacae ATCC 13047, and 30 (52%) were graded as weak mutators exhibiting a more than five-fold and not more than 50-fold increase in the mutation frequency. The isolates with higher grade of mutation frequency were resistant to significantly more antimicrobials (medians of two, one and zero agents for strong mutators, weak mutators and non-mutators, respectively; p 0.0078). The 59 isolates were classified into 36 genotypes, and all of the seven strong mutators had distinct genotypes. Mutation frequencies varied more than 10(2)-fold within a clone. In patient-based, univariate analysis, intensive-care unit admission, dense antimicrobial exposure (glycopeptide or multiple classes) and repetitive detection of this species were significantly more common among all of the four patients from whom strong mutators were obtained. Strong mutators are highly prevalent in surgical isolates of E. cloacae. Higher mutation frequency was associated with antimicrobial resistance and repetitive detection, and may contribute to the adaptability of this species.

Characterization of a 2,4-dinitrochlorobenzene-induced chronic dermatitis model in rats

Although many mouse models of atopic dermatitis have been reported, few rat models have been studied. In this study, a rat chronic allergic dermatitis model was developed and evaluated as a pharmacological model of atopic dermatitis. Prominent ear thickening and scratching were induced after the application of 2,4-dinitrochlorobenzene to the right ear of Brown Norway rats 3 times per week for 3 weeks. Histopathologically, infiltration of T cells in the ear was observed on day 7, and eosinophils and mast cells were found in addition to T cells on day 21. The expression of interferon-gamma and interleukin-4 was increased on day 7 when compared with normal rats. However, interferon-gamma expression had disappeared by day 21. Tacrolimus ointment applied after ear tissue thickening fully developed, suppressed chronic dermatitis in a dose-dependent manner. This model has some symptomatic and histopathological similarities to atopic dermatitis and might be useful in pharmacological studies.

Effects on spectrum and susceptibility patterns of isolates causing bloodstream infection by restriction of fluoroquinolone prophylaxis in a hematology-oncology unit

The emergence of fluoroquinolone-resistant gram-negative organisms has been demonstrated in patients given fluoroquinolone prophylaxis. To prevent increases in resistant bacteria, we restricted prophylactic use of fluoroquinolones. The spectrum and susceptibility patterns of isolates causing bloodstream infection (BSI) were assessed in patients receiving chemotherapy during periods of routine prophylaxis (period A: October 2001 to May 2003) and restricted prophylaxis (period B: June 2003 to January 2005). The total number of patients receiving chemotherapy was 442 during period A and 365 during period B. No significant differences were seen between periods with respect to patient characteristics. BSI was identified in 42 patients (44 episodes) during period A and 69 patients (74 episodes) during period B. Incidence of BSI increased significantly from 10.0% (44/442) during period A to 20.3% (74/365) during period B (P < 0.0001). Rate of Enterobacteriaceae BSI increased significantly, from 2.0% (9/442) during period A to 8.2% (30/365) during period B (P < 0.0001). For all BSI episodes, the proportion of BSI with gram-positive cocci decreased from 63.6% (28/44) during period A to 44.6% (33/74) during period B (P = 0.045), while the proportion of BSI with Enterobacteriaceae increased from 20.5% (9/44) to 40.5% (30/74) (P < 0.0001). The proportion of fluoroquinolone-resistant Enterobacteriaceae BSI for all Enterobacteriaceae BSI decreased from 75% (9/12) during period A to 17% (5/30) during period B (P = 0.0078). Restriction of fluoroquinolone prophylaxis affects the etiology of BSI and reduces the proportion of drug-resistant organisms.