Progress with the regulation of radiation safety during recovery and removal of spent nuclear fuel from the site for temporary storage at Andreeva Bay on the Kola Peninsula.

In the 1960s, a shore technical base (STB) was established at Andreeva Bay on the Kola Peninsula, in northwest Russia. The STB maintained nuclear submarines and the nuclear icebreaker fleet, receiving and storing fresh and spent nuclear fuel (SNF) as well as solid and liquid radioactive waste (RW). It was subsequently re-designated as a site for temporary storage (STS) for SNF and RW. Over time, the SNF storage facilities partly lost their containment functions, leading to radioactive contamination of workshops and the site above permitted values. The technological and engineering infrastructure at the site was also significantly degraded as well as the condition of the stored SNF. At present, the STS Andreeva Bay facility is under decommissioning. This paper describes progress with the creation of safe working measures for workers involved in site remediation and SNF recovery operations, including the determination of safe shift times in high radiation areas, as part of overall optimization of safety. Results are presented for the successful application of these measures in the period 2019-2021, during which time significant SNF recovery and removal operations were completed without incident. Significant important experience has been gained to support safe removal of remaining SNF, including the most hazardous degraded fuel, as well as recovery of other higher level RW and decommissioning of the old storage buildings and structures.

[Modern understanding of bronchial asthma with fixed airflow obstruction].

The review provides data on one of the phenotypes of severe bronchial asthma it is asthma with fixed airway obstruction. According to data published today, there is no single pathway for the formation of fixed airway obstruction in patients with severe asthma. Increasing knowledge of the pathophysiology of fixed airway obstruction, as well as identifying the most significant risk factors, is essential for the successful treatment of such patients. In addition, the development of fixed obstruction is associated with a worse and sometimes fatal prognosis. Expanding the existing views is also necessary to overcome the difficulties of differential diagnosis between bronchial asthma with fixed airway obstruction and bronchial asthma in combination with COPD. All this will optimize the approach to the management of patients with bronchial asthma to prevent the formation of fixed airway obstruction.

[The role of Piwi nuclear localization in the differentiation and proliferation of germline stem cells].

The Piwi protein and its orthologs are considered as the key components of the piRNA machinery implicated in transcriptional silencing of transposons. Неre, we show that nuclear localization of the Piwi protein is required not only for transposon repression, but also for proper differentiation of germline stem cells (GSCs). piwi^(Nt) mutation that causes loss of nuclear Piwi and its retention in the cytoplasm leads to the accumulation of undifferentiated GSC-like cells. The analysis of piwi^(Nt) mutation in combination with a bam gene mutation blocking GSC differentiation shows that the loss of nuclear Piwi decreases GSC proliferation rate. This is accompanied by the accumulation of DNA double-strand breaks in GSCs that may be caused by transposition events. Here, for the first time a set of transposons repressed by Piwi in GSCs and surrounding niche cells has been identified. The present study together with our previous data show that nuclear and cytoplasmic Piwi can regulate different stages of the functioning of germinal cells: cytoplasmic Piwi is sufficient to maintain GSCs, while nuclear Piwi localization is necessary for their proper proliferation and differentiation.

Transforming growth factor beta1 gene expression during vaginal wound healing in a rabbit menopause model.

OBJECTIVE: Surgical outcome following reconstructive pelvic surgery is largely dependent on the vaginal wound healing process. As peri- and post-menopausal women are the most likely candidates to undergo these surgeries, it is important to understand the effect of estrogen deficiency on this process. Transforming growth factor beta (TGFß) is an important mediator of wound healing. We sought to assess TGFß1 gene expression during the vaginal incisional wound healing process in a rabbit menopause model. DESIGN: Animal study. SETTING: Animal laboratory. SAMPLE: Sixty-three rabbits were used for this study. METHODS: Twenty-one underwent bilateral oophorectomy, 21 underwent a sham surgery, and 21 served as controls. Eight weeks later, standardised full-thickness 6-mm diameter circular segments were excised from the vagina of all rabbits. Animals were killed sequentially, before wounding, and at 0, 4, 7, 14, 21 and 35 days after wounding, and the wounds were harvested. MAIN OUTCOME MEASURES: Wound closure and TGFß1 gene transcription, as measured by real-time polymerase chain reaction (PCR). RESULTS: Wound closure was significantly protracted (P < 0.02), whereas TGFß1 gene expression was significantly increased (P < 0.0001) during the wound healing process in oophorectomised rabbits, as compared with both control and sham groups. CONCLUSION: Oophorectomised rabbits show protracted incisional vaginal wound healing associated with increased TGFß1 gene transcription.

Castleman disease in pregnancy.

BACKGROUND: Castleman disease, a rare disorder characterized by benign proliferation of lymphoid tissues, generally presents as a solitary mediastinal mass. We report the first case of this disease during pregnancy. CASE: A 32-year-old woman presented with a large abdominal mass and vaginal bleeding during the second trimester of pregnancy. Abdominal ultrasound demonstrated a large, retroperitoneal solid mass of mixed echogenicity and increased vascularity. The patient underwent explorative laparotomy that revealed a mesenteric mass, histologically consistent with Castleman disease of the hyaline-vascular type. The mass was excised completely, and the immediate postoperative course was uneventful, although the patient went into spontaneous preterm labor during the 29th week of pregnancy. CONCLUSION: Castleman disease should be considered one of the benign etiologies for an abdominal or retroperitoneal mass during pregnancy.

Indomethacin for preterm labor: a randomized comparison of vaginal and rectal-oral routes.

OBJECTIVE: To compare the efficacy of intravaginal and intrarectal plus oral indomethacin for the treatment of preterm labor. METHODS: Between December 1996 and November 1998, 46 eligible gravidas admitted with singleton pregnancies and idiopathic preterm labor before 33 gestational weeks were randomized to receive 200 mg of intravaginal or intrarectal plus oral indomethacin. RESULTS: Twenty-three subjects were allocated to each study group. The interval from initiation of treatment to delivery was significantly longer in the intravaginal indomethacin group (26.5 +/- 5.7 versus 12.6 +/- 3.7 days; P =.007). Delivery was delayed by more than 7 days in 18 of 23 subjects (78%) in the intravaginal indomethacin group compared with ten (43%) in the intrarectal plus oral indomethacin group (P =.03). Birth weights were significantly higher (2306 +/- 436 versus 1862 +/- 232 g; P =.002) and hospitalization in a neonatal intensive care unit (NICU) (3.1 +/- 0.8 versus 9.3 +/- 3. 7 days; P =.001) and mechanical ventilation (1.4 +/- 0.2 versus 5.3 +/- 1.6 days; P =.001) were significantly shorter in the intravaginal indomethacin group. CONCLUSION: Intravaginal indomethacin is more effective than intrarectal plus oral application in delaying preterm labor and is associated with higher birth weights, shorter NICU stays, and shorter intervals of mechanical ventilation.

Obstetric outcome of in vitro fertilized pregnancies complicated by severe ovarian hyperstimulation syndrome: a multicenter study.

OBJECTIVE: To assess the outcome of pregnancies conceived with the use of IVF that are complicated by severe ovarian hyperstimulation syndrome (OHSS). DESIGN: A retrospective nationwide multicenter study. SETTING: Sixteen of 19 tertiary care medical centers in Israel. PATIENT(S): All patients undergoing IVF who were hospitalized for severe OHSS between January 1987 and December 1996. MAIN OUTCOME MEASURE(S): Pregnancy rate (PR) and rates of multiple gestation, miscarriage, ectopic pregnancy, obstetric complications, and intervention. RESULT(S): A total of 163 patients who had severe OHSS after IVF treatment were identified, of whom 142 (87.1%) had undergone ET. The clinical PR was 73.2%; 42.3% were singletons, 33.6% were twins, 17.3% were triplets, and 6.7% were quadruplets. The miscarriage rate was 29.8%, whereas the incidence of ectopic pregnancy was 1.9%. Forty-four percent of all births were premature, and 62.1% of all newborns had low birth weight. The most common antenatal complications were pregnancy-induced hypertension (13.2%), gestational diabetes (5.9%), and placental abruption (4.4%). The rate of cesarean section was 44.1%. CONCLUSION(S): Among patients who have severe OHSS after IVF treatment, the pregnancy rate and the rates of multiple gestation, miscarriage, prematurity, low birth weight, pregnancy-induced hypertension, gestational diabetes, and placental abruption are significantly higher than those reported previously for pregnancies conceived with the use of assisted reproductive techniques.

Pulmonary manifestations of severe ovarian hyperstimulation syndrome: a multicenter study.

OBJECTIVE: To assess the pulmonary manifestations of severe ovarian hyperstimulation syndrome (OHSS). DESIGN: A retrospective nationwide 10-year multicenter study. SETTING: Sixteen of 19 tertiary medical centers in Israel. PATIENT(S): All patients hospitalized at these centers for severe OHSS between January 1987 and December 1996. MAIN OUTCOME MEASURE(S): Clinical presentation, arterial blood gases on room air, and chest roentgenogram results. RESULT(S): Of 209 patients, 4% had lobar pneumonia, 2% had adult respiratory distress syndrome (ARDS), and 2% had pulmonary thromboembolism. Most patients had dyspnea, tachypnea, moderate hypoxemia, increased alveolar-arterial oxygen difference, hypocarbia, respiratory alkalosis, and metabolic compensation. The most common findings on chest roentgenogram were bilateral elevation of the diaphragm, pleural effusion, and pulmonary atelectasis. Patients with pulmonary thromboembolism, ARDS, and pneumonia presented with severe hypoxemia and alveolar-arterial oxygen difference and distinct radiographic findings. CONCLUSION(S): Severe OHSS is characterized by an extraparenchymal restrictive type of pulmonary dysfunction, attributed to intraabdominal or pleural fluid accumulation, which limits descent of the diaphragm and expansion of the thoracic cage. This may induce uncoordinated lung ventilation and atelectasis with subsequent ventilation-perfusion mismatch and hypoxemia. The clinical picture may deteriorate further because of pulmonary infection, pulmonary thromboembolism, or ARDS, all of which have distinct clinical, radiographic, and blood gas characteristics.

Vascular endothelial growth factor plasma levels correlate to the clinical picture in severe ovarian hyperstimulation syndrome.

OBJECTIVE: To assess the potential involvement of vascular endothelial growth factor in the hyperpermeability characterizing the ovarian hyperstimulation syndrome (OHSS). DESIGN: A controlled clinical study that followed the kinetics of vascular endothelial growth factor in the plasma of patients with severe OHSS from the time of admission to the hospital and until clinical resolution. SETTING: Women hospitalized with severe OHSS in a tertiary medical center. PATIENT(S): Seven patients with severe OHSS after ovulation induction for IVF and seven controls who had received a similar ovulation induction regimen and did not develop the OHSS. INTERVENTION(S): Three blood samples were obtained from each OHSS patient: upon hospitalization for severe OHSS, when significant clinical improvement was evident, and on the first follow-up visit after the patients' discharge. Ascitic fluid was obtained from all OHSS patients by therapeutic paracentesis during the active phase of the syndrome. Blood samples were drawn from the control patients 4 to 6 days after ET. All samples were assayed for vascular endothelial growth factor levels, hematocrit, E2 levels, and white blood cell count. MAIN OUTCOME MEASURE(S): Vascular endothelial growth factor levels were assayed by ELISA. Estradiol was determined by RIA. RESULT(S): Compared with the controls, high levels of vascular endothelial growth factor were detected in the plasma of all patients admitted for severe OHSS. Levels dropped significantly along with clinical improvement, reaching minimum values after complete resolution. A statistically significant correlation was found between plasma vascular endothelial growth factor levels and certain biologic characteristics of OHSS and of capillary leakage such as leukocytosis and increased hematocrit. Ascitic fluid obtained from the study patients also contained high vascular endothelial growth factor levels. CONCLUSION(S): These findings suggest the involvement of vascular endothelial growth factor in the pathogenesis of capillary leakage in the OHSS.

Hydroxyethylstarch versus human albumin for the treatment of severe ovarian hyperstimulation syndrome: a preliminary report.

OBJECTIVE: To compare the efficacy and safety of 6% hydroxyethylstarch and human albumin as colloid solutions for treatment of severe ovarian hyperstimulation syndrome (OHSS). DESIGN: Controlled cohort study. SETTING: Tertiary medical center. PATIENT(S): Sixteen patients with severe OHSS. INTERVENTION(S): Six percent hydroxyethylstarch (6 patients) and human albumin (10 patients). MAIN OUTCOME MEASURE(S): Urine output, number of abdominal and pleural drainage procedures, complications, duration of hospitalization, and perinatal outcome. RESULT(S): Patients who received 6% hydroxyethylstarch had higher urine output, needed fewer abdominal and pleural paracenteses, and had a shorter hospital stay than those who received human albumin. In each group, no adverse effects or congenital malformations were observed and the rates of miscarriage were similar. CONCLUSION(S): These results suggest that 6% hydroxyethylstarch may be superior to albumin as a colloid solution for the treatment of severe OHSS.

Plasma immunoglobulins in patients with severe ovarian hyperstimulation syndrome.

OBJECTIVE: To assess immunoglobulin (Ig) concentrations in plasma and ascitic fluid of patients with severe ovarian hyperstimulation syndrome (OHSS). DESIGN: Controlled clinical study. SETTING: Tertiary medical center. PATIENT(S): Ten patients with severe OHSS after ovulation induction for IVF and 10 controls who had undergone similar ovulation induction and did not develop OHSS. INTERVENTION(S): Three blood samples were obtained from each OHSS patient: one at the time of hospitalization for severe OHSS, one when significant clinical improvement was evident, and one at the first follow-up visit after discharge from the hospital. Blood samples were drawn from control patients 6-8 days after ET. Ascitic fluid was obtained from all patients with OHSS by therapeutic paracentesis. MAIN OUTCOME MEASURE(S): Immunoglobulin concentrations were assayed by radial immunodiffusion. RESULT(S): Significantly lower levels of gamma-globulins, specifically IgG and IgA, were detected in the plasma of patients with severe OHSS, whereas alpha- and beta-globulin levels as well as IgM levels were not significantly different from those in controls. Both IgG and IgA levels increased as patients clinically improved. Ascitic fluid contained high IgG, moderate IgA, and negligible IgM levels. CONCLUSION: Severe OHSS is characterized by hypogammaglobulinemia, attributed to leakage of medium-molecular-weight immunoglobulins such as IgG and IgA to the peritoneal cavity.

Soluble ICAM-1 and E-selectin levels correlate with clinical and biological aspects of severe ovarian hyperstimulation syndrome.

OBJECTIVE: To assess the potential involvement of the soluble endothelial cell-leukocyte adhesion molecules E-selectin and intercellular adhesion molecule-1 (ICAM-1) in the pathophysiology of capillary hyperpermeability in the ovarian hyperstimulation syndrome (OHSS). DESIGN: Controlled clinical study. SETTING: Women hospitalized for severe OHSS after ovulation induction for IVF at two tertiary medical centers. PATIENT(S): Eleven patients with severe OHSS undergoing IVF and 20 controls who had received a similar ovulation induction regimen and did not develop OHSS. INTERVENTION(S): Serial serum samples were obtained from all patients with OHSS from admission until discharge. Ascitic fluid was obtained from all patients by therapeutic paracentesis. Serum was obtained from all controls 4-8 days after ET. MAIN OUTCOME MEASURE(S): Samples were assayed for soluble E-selectin and soluble ICAM-1 by using enzyme-linked immunosorbent assay and results were correlated with clinical and biological aspects of OHSS. RESULT(S): Compared with controls, patients with severe OHSS had higher levels of soluble ICAM-1 and lower levels of soluble E-selectin detected in serum and ascites. Serum levels of soluble ICAM-1 decreased, while soluble E-selectin levels increased along with clinical and biological improvement. Serum soluble ICAM-1 showed significant positive correlation and serum soluble E-selectin showed significant negative correlation with clinical and biological aspects of severe OHSS. CONCLUSION(S): Soluble ICAM-1 and soluble E-selectin seem to be involved in the pathophysiology of capillary hyperpermeability in severe OHSS.

Ruptured tubo-ovarian abscess complicating transcervical cryopreserved embryo transfer.

OBJECTIVE: To present a rare infectious complication related to transcervical ET, without prior transvaginal puncture. DESIGN: Case report. SETTING: Hadassah University Hospital, IVF-ET unit. PATIENT: One patient undergoing cryopreserved-thawed ET. INTERVENTIONS: Artificial preparation of the endometrium with E2 and P, followed by transcervical intrauterine cryopreserved-thawed embryo transfer. RESULTS: After ET, severe pelvic inflammatory disease (PID) with ruptured tubo-ovarian abscess was diagnosed and treated. CONCLUSIONS: Severe PID including tubo-ovarian abscess formation should be considered a potential complication after ET, even without transvaginal oocyte aspiration.

Characterization of intraperitoneal cytokines and nitrites in women with severe ovarian hyperstimulation syndrome.

OBJECTIVE: To assess the potential involvement of cytokines and nitrites in the hyperpermeability characterizing the ovarian hyperstimulation syndrome (OHSS). DESIGN: A controlled clinical study comparing peritoneal fluid (PF) from patients with severe OHSS and from non-OHSS controls. SETTING: Women hospitalized with severe OHSS in three tertiary medical centers. PATIENTS: Twelve patients with severe OHSS necessitating paracentesis and 20 non-OHSS controls. INTERVENTIONS: The criteria for ultrasound-guided paracentesis were tense ascites, hydrothorax, hemoconcentration, or oliguria. MAIN OUTCOME MEASURES: Interleukin (IL) 1 beta IL-1 receptor agonist, IL-2, IL-6, IL-8, and tumor necrosis factor alpha (TNF alpha) levels in PF were assayed by ELISA; nitrites were measured by the "Griess" reaction. Estradiol and P were determined by RIA. RESULTS: Ovarian hyperstimulation syndrome patients had significantly higher PF IL-6 (3,523 versus 30 pg/mL), TNF alpha (14 versus 4.2 pg/mL), and IL-8 (1,695 versus 900 pg/mL). In the serum, only IL-6 levels were significantly higher (375 versus 11 pg/mL). Conversely, nitrite levels were significantly lower in PF of OHSS patients (0.5 versus 34 nmol/mL). Interleukin 1 levels were higher and IL-1 receptor antagonist levels were lower in OHSS patients, suggesting potentially increased biologic potency of IL-1. CONCLUSION: These findings suggest that these substances could be involved in mediating the capillary hyperpermeability characterizing this syndrome.

Surgical treatment of vulvar lichen sclerosus: a review.

Surgical therapy of lichen sclerosus of the vulva consists of three main operations: vulvectomy (with or without a skin graft), cryosurgery, and laser ablation. It is indicated in two conditions, either when malignant transformation is present or is likely to occur, or when medical treatment has failed. The overall risk for malignant transformation of vulvar lichen sclerosus is low, ranging between 0 and 9 percent. However, specific histological criteria, such as mixed dystrophy, have recently been associated with higher malignancy rates. Vulvectomy is indicated only when these criteria are met. Both skinning and simple vulvectomies are associated with recurrence rates as high as 50 percent. However, better sexual function and cosmetic results have been reported in the former, especially with concomitant split skin grafting. Cryosurgery also has high recurrence rates, although short-term results are favorable. Although only small series have been reported, laser therapy seems to carry better long-term results than other modes of treatment. Convalescence is complete within 6 weeks posttreatment, and remission rates are as high as 85 percent at 3 years of follow-up. The high recurrence rate of all surgical modalities makes surgical treatment suitable only for patients who failed to respond to multiple medical treatments such as topical high potent steroid ointments, testosterone, and retinoids.

Density-optimized radial exponents for X-ray charge-density refinement from ab initio crystal calculations.

Structure factors based on periodic density-functional (DFT) calculations on 25 molecular crystals have been used to evaluate trends in refined values of the kappa and kappa' expansion-contraction parameters of the Hansen-Coppens multipole formalism. As found previously and expected physically, the spherical-valence-shell kappa parameters are closely related to the net atomic charges, negative atoms being expanded and vice versa. kappa' parameters, which scale the radial dependence of the non-spherical deformation functions, are remarkably consistent for particular bonding environments. Systematic trends are observed for both carbon and oxygen, but the values obtained for nitrogen show a larger variation. Average values for oxygen and carbon in different bonding environments are tabulated and can be used whenever refinement of experimental data is affected by lack of uniqueness of the charge-density parameter set. Values for nitrogen must be more finely tuned to the specific bonding environment. The relation between atomic charge and kappa offers the possibility of introducing a constraint in the charge-density refinement of very large molecules, for which reduction of the size of the parameter set may be essential.

The experimental charge-density approach in the evaluation of intermolecular interactions. Application of a new module of the XD programming package to several solids including a pentapeptide.

A new module interfaced to the XD programming package has been used in the evaluation of intermolecular interactions and lattice energies of the crystals of p-nitroaniline, L-asparagine monohydrate and the pentapeptide Boc-Gln-D-Iva-Hyp-Ala-Phol (Boc = butoxycarbonyl, Iva = isovaline = ethylalanine, Phol = phenylalaninol). The electrostatic interactions are evaluated with the atom-centered distributed multipoles from KRMM (kappa'-restricted multipole model) refinements, using the Buckingham expression for non-overlapping charge densities. Results for p-nitroaniline are compared with Hartree-Fock (HF), density functional (DFT) and Moller-Plesset (MP2) supermolecular calculations and with HF and DFT periodic calculations. The HF and DFT methods fail to predict the stability of the p-nitroaniline crystal but the results of the experimental charge-density approach (ECDA) are in good agreement with both MP2 interaction energies and the experimental lattice energy. ECDA results for L-asparagine monohydrate compare well with those from DFT supermolecular and periodic HF calculations. The disorder of the terminal group in the pentapeptide, which persists at the experimental temperature of 20 K, corresponds to an energy difference of only 0.35 kJ mol(-1), which is too small to be reproduced with current methods.

Increased levels of basic fibroblast growth factor are found in the cross-clamped heart during cardiopulmonary bypass.

BACKGROUND: High concentrations of fibroblast growth factors (FGFs) are found in the heart. Even higher levels are measured during ischemia. Exogenous administration of FGF to ischemic myocardium promotes synthesis of collateral coronary circulation and induces local myocardial hypertrophy. The kinetics and the contribution of the heart and lungs to circulating basic FGF (bFGF) levels during cardiac surgery were characterized. PATIENTS AND METHODS: Plasma bFGF levels were measured in seven adults undergoing coronary artery bypass operations and 11 neonates undergoing congenital cardiac anomaly repair during cardiopulmonary bypass. RESULTS: In both the adult and the neonatal groups, bFGF plasma levels increased significantly immediately after removal of the aortic cross-clamp (adult group 15.43+/-6.3 aorta cross-clamped versus 29+/-4.1 after release, P=0.011; neonatal group 17.09+/-9.43 aorta cross-clamped versus 43.55+/-14.25 after release, P=0.004) and declined thereafter. In the adult group, higher levels of bFGF were recorded in blood recovered from the coronary sinus than in the aortic root during aortic cross-clamping (63.14+/-14.42 versus 43.86+/-12.05, P=0.011), and in both, levels were significantly higher than the peripheral measurements. CONCLUSIONS: Plasma bFGF levels increase during cardiopulmonary bypass. The source of this elevation is the lungs and heart.

Verapamil increases the bacteriostatic and bactericidal effects of adriamycin on Escherichia coli.

The purpose of this study was to evaluate the effect of verapamil on adriamycin-resistant and -sensitive Escherichia coli bacterial strains. Two E. coli strains: B-SR9 and K12-KL16 were incubated with adriamycin in various concentrations in the presence or absence of verapamil. Growth and killing rates were measured using optical densities and colonogenic assays. Transmembrane transport capacity was evaluated by measuring radioactively labelled leucine uptake and intracellular potassium concentrations. While adriamycin (ADR) showed both bacteriostatic and bactericidal effects upon the two bacterial strains, the K12 strain was significantly more resistant to the drug than its peer. Subtoxic concentrations of verapamil augmented these effects in both strains. Verapamil affected bacterial transmembrane transport activity and caused potassium leakage through the cell membrane. Simultaneous exposure to adriamycin and verapamil resulted in rapid, massive damage to membrane functions, indicating accelerated killing rate. The authors concluded that verapamil acts as a potentiator of adriamycin's cytotoxicity in E. coli bacteria in a manner similar to that in multidrug resistant mammalian tumour cells. This observation suggests that the mechanisms of resistance to the drug may be similar in both species.

Intrapartum fetal pulse oximetry: present and future.

Pulse oximetry is widely used to monitor the patient's well-being in anesthetic and neonatal practice. As a result of recent technologic and theoretical advances, it has emerged as a clinical tool in intrapartum fetal monitoring. Oximeters record both pulse rate and arterial oxygen saturation of the fetus and they may be adapted to derive an estimate of peripheral perfusion. Reflectance oximetry is more accurate than transmission oximetry in intrapartum fetal management. This method uses the pulsatile changes of red and infrared light reflected from tissue to estimate arterial oxygenation. Pulse oximetry is cheap, non-invasive, simple to operate, relatively accurate and has a fast response time. Factors adversely affecting the accuracy of the pulse oximeter output include transducer displacement, peripheral vasoconstriction, hypotension, anemia, presence of intravascular dyes, meconium staining, fetal hair and scalp edema. Fetal pulse oximetry is limited by a wide normal range and inadequate calibration. The amniochorionic membranes however do not affect oximetry readings so that this method may be applied before rupture of the membranes, i.e. before labor. Once successfully developed, fetal pulse oximetry could potentially be used in combination with other monitoring techniques to reduce instrumental and operative interventions during labor and improve perinatal outcome.