BACKGROUND & AIMS: PROBLEM:Thrombophilia has been associated with poor obstetrical outcomes. To determine the association of specific inherited thrombophilias and recurrent pregnancy loss, 10 thrombophilic genes were investigated. METHOD OF STUDY:A total of 550 women with a history of recurrent pregnancy loss had buccal swabs taken for DNA analyses of the following gene mutations: factor V G1691A, factor V H1299R (R2), factor V Y1702C, factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), methylenetetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C. The frequencies of these mutations were compared with controls published in the literature. RESULTS:When examined individually, PAI-1 4G/5G (P = 0.009), factor XIII V34L (P < 0.0001), and homozygous MTHFR C667T (P < 0.0001) correlated significantly with recurrent pregnancy loss compared with controls. The frequency of the factor V Y1702C mutation was extremely low in patients and controls; thus, this gene was removed from further calculations. The remaining six mutated genes, when analyzed cumulatively, also corresponded with recurrent pregnancy loss (P < 0.0001). CONCLUSION:A panel of thrombogenic gene mutations consisting of factor V G1691A, factor V H1299R (R2), factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), MTHFR C677T, and MTHFR A1298C can identify individuals at risk for recurrent pregnancy loss.

背景与目标：

BACKGROUND & AIMS: :Bioelectrical fetal heart activity being recorded from maternal abdominal surface contains more information than mechanical heart activity measurement based on the Doppler ultrasound signals. However, it requires extraction of fetal electrocardiogram from abdominal signals where the maternal electrocardiogram is dominant. The simplest technique for maternal component suppression is a blanking procedure, which relies upon the replacement of maternal QRS complexes by isoline values. Although, in case of coincidence of fetal and maternal QRS complexes, it causes a loss of information on fetal heart activity. Its influence on determination of fetal heart rate and the variability analysis depends on the sensitivity of the heart-beat detector used. The sensitivity is defined as an ability to detect the incomplete fetal QRS complex. The aim of this work was to evaluate the influence of the maternal electrocardiogram suppression method used on the reliability of FHR signal being calculated.

背景与目标： : 从母体腹部表面记录的生物电胎儿心脏活动比基于多普勒超声信号的机械心脏活动测量包含更多信息。但是，它需要从母体心电图占主导地位的腹部信号中提取胎儿心电图。抑制母体成分的最简单技术是消隐程序，该程序依赖于用等值线值代替母体QRS复合物。尽管在胎儿和母体QRS复合物重合的情况下，它会导致有关胎儿心脏活动的信息丢失。它对确定胎儿心率和变异性分析的影响取决于所使用的心跳检测器的灵敏度。敏感性定义为检测不完整胎儿QRS复合物的能力。这项工作的目的是评估所使用的母体心电图抑制方法对所计算的FHR信号可靠性的影响。

BACKGROUND & AIMS: :The aim of this study was to assess the clinical value of serum oestradiol concentration 8 days after embryo transfer (D8E2) and beta-human chorionic gonadotrophin (HCG-beta) concentration 12 days after embryo transfer (D12HCG-beta) in the prediction of pregnancy and the outcome of pregnancy following assisted reproduction, taking into account the day of transfer, which was either day 3 (D3) or day 5 (D5). The objective was to improve patient counselling by giving quantitative and reliable predictive information instead of non-specific uncertainties. A total of 2035 embryo transfer cycles performed between January 2003 and June 2005 were analysed retrospectively. Biochemical pregnancy, ectopic pregnancy and first-trimester abortions were classified as non-viable pregnancies; pregnancies beyond 12 weeks gestation were classified as ongoing pregnancies (OP). Significantly higher D8E2 and D12HCG-beta were obtained in D5 transfers compared with D3 transfers with regard to pregnancy and OP (P

BACKGROUND & AIMS: :Consonant identification was measured for a stationary and amplitude-modulated noise masker in four listeners with flat cochlear hearing loss, and four age-matched normal-hearing listeners. The masker modulation rate was systematically varied between 2 and 128 Hz. Masking release (MR), that is better identification performance in fluctuating, than in stationary noise, was highest in a masker fluctuating at 8-16 Hz in all normal-hearing listeners. In comparison, MR was only observed in two out of the four impaired listeners. In these listeners, MR was poorer than normal, and peaked at lower rates, that is 2 or 8 Hz. MR corresponded to increased reception of information for voicing, place, and manner between 2 and 64 Hz in all normal-hearing listeners. In impaired listeners, increased reception of information was mainly observed for manner, and mainly reduced for place, but these differences were not significant. For all phonetic features, MR was observed at lower masker fluctuation rates (< or =32 Hz) than in normal-hearing listeners. This study therefore shows that cochlear damage affects MR, both quantitatively and qualitatively.

背景与目标： : 在四个患有扁平耳蜗听力损失的听众和四个年龄匹配的正常听力听众中，测量了固定和幅度调制的噪声masker的辅音识别。掩蔽器调制速率在2和128Hz之间系统地变化。在所有正常听力的听众中，掩蔽释放 (MR) 在波动中比在固定噪声中更好的识别性能，在8-16Hz波动的掩蔽器中最高。相比之下，仅在四个受损听众中的两个中观察到MR。在这些听众中，MR比正常人差，并且以较低的速率 (即2或8Hz) 达到峰值。MR对应于所有正常听力的听众在2到64Hz之间的发声，位置和方式的信息接收增加。在受损的听众中，主要观察到方式的信息接收增加，而地点的信息接收则主要减少，但这些差异并不显着。对于所有语音特征，与正常听力的听众相比，以较低的掩蔽率 (<或 = 32Hz) 观察到MR。因此，这项研究表明，耳蜗损伤在定量和定性上都会影响MR。

BACKGROUND & AIMS: :Botulism during pregnancy is uncommon and raises concern due uncertainty about fetal impairment. This type of situation has not been reported to date. Treatment is basically symptomatic and based on nursing care. The prognosis is tightly correlated with the maternal status. Dietary hygiene is the basis of prevention. We describe a case of botulism occurring during the second quarter of pregnancy.

背景与目标： : 怀孕期间肉毒中毒并不常见，由于胎儿受损的不确定性，引起了人们的关注。迄今为止尚未报告这种情况。治疗基本以对症为主，以护理为主。预后与孕产妇状况密切相关。饮食卫生是预防的基础。我们描述了在怀孕第二季度发生的肉毒中毒病例。

BACKGROUND & AIMS: Endoscopic transthoracic sympathicotomy (ETS) is a recently developed technique to divide sympathetic nerves. ETS has been shown to improve symptoms and reduce ischemia in patients with severe angina pectoris. Low heart rate variability (HRV) in patients with ischemic heart disease carries an adverse prognosis. HRV reflects autonomic response of the heart and a shift in the sympathovagal balance towards parasympathetic dominance could be a marker of improved prognosis. HRV might also be used as an indicator of surgical success in sympathetic heart denervation. Heart rate was recorded in 57 patients before and after ETS. Registration was recorded during controlled respiration in the supine position and at tilt test over 10 minutes and spectral analysis was performed. Twenty-four hour Holter recordings were analyzed in the time domain. During the controlled setting, the high-frequency (HF) component (0.15 to 0.40 Hz) increased significantly whereas the low-frequency (LF) component (0.04 to 0.15 Hz) did not change significantly. The LF/HF ratio at tilt test was reduced from 1.3 to 0.8 (p <0.01). The time-domain analysis showed a significant increase of the mean RR interval (923 to 1,006 ms, p <0.001) and indexes reflecting parasympathetic tone also increased significantly (the root-mean square of difference measured from 24.3 to 29.5 ms, p <0.001 and the proportion of adjacent RR intervals >50% measured from 5.5% to 8.2%, p <0.01), whereas measurements reflecting global HRV did not change. In addition to relief of symptoms and reduced ischemia in severe angina pectoris, ETS caused a shift of sympathovagal balance toward parasympathetic tone. This might explain the anti-ischemic effect and have prognostic implications.

背景与目标： 内镜经胸交感神经切开术 (ETS) 是最近开发的一种分裂交感神经的技术。ETS已被证明可以改善严重心绞痛患者的症状并减少缺血。缺血性心脏病患者的低心率变异性 (HRV) 具有不利的预后。HRV反映了心脏的自主反应，交感神经平衡向副交感神经优势的转变可能是预后改善的标志。HRV也可以用作交感神经去神经支配手术成功的指标。在ETS前后记录了57例患者的心率。在仰卧位和倾斜测试的控制呼吸过程中记录了10分钟以上的记录，并进行了光谱分析。在时域中分析了24小时Holter记录。在受控设置期间，高频 (HF) 分量 (0.15至0.40Hz) 显着增加，而低频 (LF) 分量 (0.04至0.15Hz) 没有显着变化。倾斜试验时的LF/HF比从1.3降低到0.8 (p <0.01)。时域分析显示，平均RR间隔显着增加 (923至1,006 ms，p <0.001)，反映副交感神经张力的指标也显着增加 (从24.3至29.5 ms测量的均方根差异，p <0.001和相邻RR区间的比例> 50% 从5.5% 到8.2% 测量，p <0.01)，而反映整体HRV的测量没有变化。除了缓解症状和减少严重心绞痛的缺血外，ETS还导致交感神经平衡向副交感神经张力转移。这可能解释了抗缺血作用并具有预后意义。

BACKGROUND & AIMS: By rigorous statistical standards, the expression false negative rate is a misnomer because the concept of "rate" is associated with the rapidity of change of phenomena per unit of time or other variable (e.g., temperature). Uncertainty about the term false negative rate resulted in the introduction of similar but equally dubious expressions, including false negative fraction and miss rate. The statistically correct term in the practice of cytopathology is false negative proportion because we have here a fraction in which the numerator (number of false negative cases) is a part of the denominator (number of true positive cases plus number of false negative cases). This is the classic definition of the term proportion.

背景与目标： 根据严格的统计标准，假阴性率的表述是错误的，因为 “率” 的概念与每单位时间或其他变量 (例如温度) 的现象变化的速度有关。对术语假阴性率的不确定性导致引入了相似但同样可疑的表达，包括假阴性率和漏报率。在细胞病理学实践中，统计上正确的术语是假阴性比例，因为我们这里有一个分数，其中分子 (假阴性病例数) 是分母的一部分 (真阳性病例数加上假阴性病例数)。这是比例一词的经典定义。

BACKGROUND & AIMS: BACKGROUND:Abnormal respiratory rates are one of the first indicators of clinical deterioration in emergency department(ED) patients. Despite the importance of respiratory rate observations, this vital sign is often inaccurately recorded on ED observation charts, compromising patient safety. Concurrently, there is a paucity of research reporting why this phenomenon occurs. OBJECTIVE:To develop a substantive theory explaining ED registered nurses' reasoning when they miss or misreport respiratory rate observations. DESIGN:This research project employed a classic grounded theory analysis of qualitative data. PARTICIPANTS:Seventy-nine registered nurses currently working in EDs within Australia. Data collected included detailed responses from individual interviews and open-ended responses from an online questionnaire. METHODS:Classic grounded theory (CGT) research methods were utilised, therefore coding was central to the abstraction of data and its reintegration as theory. Constant comparison synonymous with CGT methods were employed to code data. This approach facilitated the identification of the main concern of the participants and aided in the generation of theory explaining how the participants processed this issue. RESULTS:The main concern identified is that ED registered nurses do not believe that collecting an accurate respiratory rate for ALL patients at EVERY round of observations is a requirement, and yet organizational requirements often dictate that a value for the respiratory rate be included each time vital signs are collected. The theory 'Rationalising Transgression', explains how participants continually resolve this problem. The study found that despite feeling professionally conflicted, nurses often erroneously record respiratory rate observations, and then rationalise this behaviour by employing strategies that adjust the significance of the organisational requirement. These strategies include; Compensating, when nurses believe they are compensating for errant behaviour by enhancing the patient's outcome; Minimalizing, when nurses believe that the patient's outcome would be no different if they recorded an accurate respiratory rate or not and; Trivialising, a strategy that sanctions negligent behaviour and occurs when nurses 'cut corners' to get the job done. Nurses' use these strategies to titrate the level ofemotional discomfort associated with erroneous behaviour, thereby rationalising transgression CONCLUSION: This research reveals that despite continuing education regarding gold standard guidelines for respiratory rate collection, suboptimal practice continues. Ideally, to combat this transgression, a culture shift must occur regarding nurses' understanding of acceptable practice methods. Nurses must receive education in a way that permeates their understanding of the relationship between the regular collection of accurate respiratory rate observations and optimal patient outcomes.

背景与目标：

BACKGROUND & AIMS: OBJECTIVES:Monochorionic (MC) twins are at increased risk of early fetal loss secondary to vascular complications such as twin-twin transfusion syndrome (TTTS). This study compared the early perinatal loss rates between MC and dichorionic (DC) twins in an era of invasive treatment for TTTS. METHODS:This was a retrospective study of all twin pregnancies of known chorionicity from a large regional cohort of nine hospitals over a 10-year period. Ultrasound data were matched to hospital delivery records and to a mandatory national register of pregnancy losses. Prospective risk of pregnancy loss from 14 to 24 weeks' gestation was calculated and the survival trend of MC and DC twins was analyzed using Kaplan-Meier survival analysis. RESULTS:The analysis included 3117 twin pregnancies (605 MC and 2512 DC). The total risk of early pregnancy loss (miscarriage and neonatal death) before 24 weeks was significantly higher in MC twins (60.3 per 1000 fetuses) than in DC twins (6.6 per 1000 fetuses), with a relative risk of 9.18 (95% CI, 6.0-13.9). Survival analysis showed a significant difference in overall and early mortality between MC and DC twins (log-rank test, P < 0.0001), while no difference was noted after 24 weeks' gestation (log-rank test, P = 0.08). CONCLUSIONS:Early pregnancy loss is significantly more common in MC than in DC twins, but no difference in the prospective risk of mortality between MC and DC twins is evident after 24 weeks' gestation. The observed early mortality rate has almost halved in comparison with previous studies in the published literature. Early detection and prompt treatment of complications in MC twins are likely to have contributed to this improvement in outcome.

背景与目标：

BACKGROUND & AIMS: :Fetal growth, birth weight specific mortality rates and effect of sick leave or hospitalization on the fetal growth were investigated in a material of 476 twin pregnancies managed at University Central Hospital of Turku in years 1970-81. Birth weights of twin babies at any gestational age were slightly but not significantly higher than in earlier materials. When compared to growth curve of singleton fetuses, the growth rate of both twins is equal to singletons up to 30th week of pregnancy, being thereafter slower than in singleton pregnancies. Although duration of sick leave and hospitalization increased considerably during the study period, no change in the duration of pregnancy nor in the weight of twin babies occurred. Instead perinatal mortality decreased from 101/per thousand to 36.2/per thousand. Birth weight specific mortality rates did not differ from those in singleton fetuses.

背景与目标： : 在图尔库大学中央医院1970-81年管理的476例双胎妊娠材料中，研究了胎儿生长，出生体重特定死亡率以及病假或住院对胎儿生长的影响。在任何胎龄的双胞胎婴儿的出生体重均略高于但不显着高于早期材料。与单胎胎儿的生长曲线相比，两个双胞胎的生长速度等于怀孕第30周的单胎，此后比单胎妊娠慢。尽管在研究期间病假和住院时间大大增加，但怀孕时间和双胞胎婴儿的体重没有变化。相反，围产期死亡率从101/每千下降到36.2/每千。出生体重特定死亡率与单胎胎儿没有差异。

BACKGROUND & AIMS: BACKGROUND:Hormone replacement therapy increases the number and quality of grafts recovered from brain-dead organ donors. Arginine vasopressin (AVP) has also been shown to have beneficial effects. The aim of this study was to determine the effect of AVP on recovery rates. METHODS:The Organ Procurement and Transplantation Network database was used. Donors treated with hormone replacement therapy and vasopressor agents who were successfully procured between January 1, 2009, and June 30, 2011, were studied. AVP-positive and AVP-negative donors were compared. The primary study end point was the rate of high-yield procurement (≥4 organs). RESULTS:A total of 10,431 donors were included. AVP was infused in 7,873 (75.5%) and was associated with an increased rate of high-yield procurement (50.5% vs 35.6%, P < .001). There was less overall graft refusal due to poor function (38.9% vs 45.6%, P < .001). AVP independently predicted high yield procurement. CONCLUSIONS:The use of AVP with hormone replacement therapy is independently associated with an increased rate of organ recovery. This strategy should be universally adopted in the management of donors progressing to neurologic death.

背景与目标：

BACKGROUND & AIMS: OBJECTIVES:To estimate the agreement between prenatal ultrasonography observations at 16 - 21 gestational weeks and fetal autopsy findings in pregnancies terminated because of fetal anomalies. STUDY DESIGN:This 4½ year retrospective study includes consecutive fetuses that were terminated because of fetal malformation and/or chromosomal anomaly diagnosed in the second trimester. Only fetuses that had undergone fetal anatomy scanning by an obstetrician trained in fetal ultrasound before the termination and with available fetal autopsy reports were included. The cases were identified through the malformation registry database of our ultrasound unit. The sensitivity and specificity of ultrasound were calculated per organ system. When estimating the agreement between ultrasound results and autopsy findings, the cases were allocated to one of four categories according to the degree of concordance between ultrasound and autopsy findings: full agreement, near match, partial agreement and unconfirmed ultrasound findings. RESULTS:71 of 95 pregnancy terminations due to fetal malformations met the inclusion criteria and constitute our study population. The sensitivity of ultrasonography with regard to malformations in the brain and spine was 100 % (27/27) and with regard to malformations in the internal organ system (including malformations in the urogenital and gastrointestinal systems and in the abdominal wall and diaphragm) was 91 % (30/33). The corresponding figures for malformations in the cardiovascular and skeletal organ systems were 63 % (17/27) and 71 % (25/35), respectively. The specificity was lowest for malformations in the central nervous system and internal organ system (33/38, 87 % and 39/44, 89 %, respectively). There was full agreement between the ultrasound and autopsy findings in 44 % (31/71) of all cases and a near match in 46 % (33/71) of cases. In almost 10 % (7/71) of the pregnancies, the ultrasound findings were only partially confirmed or not confirmed by autopsy. In one case the discrepancy between the ultrasound and autopsy findings suggests that the pregnant woman might have decided to terminate the pregnancy on the basis of incorrect interpretation of ultrasound findings. CONCLUSION:Even though the agreement between ultrasound and autopsy findings was acceptable from a clinical point of view, agreement with regard to the detailed description of malformations was far from perfect. The detection rates were suboptimal for the cardiovascular and skeletal organ systems. :ZIEL:: Bewertung, inwieweit bei Schwangerschaftsabbrüchen aufgrund fetaler Anomalien die Befunde der pränatalen Ultraschalluntersuchung in der 16.–21. SSW mit dem Autopsiebefund des Feten übereinstimmen. METHODEN:Diese 4½ jährige retrospektive Studie schließt fortlaufend Feten ein, bei denen im 2. Trimenon ein Schwangerschaftsabbruch (TOP) aufgrund fetaler Fehlbildungen und/oder aufgrund von diagnostizierten Chromosomenanomalien erfolgt ist. Es wurden nur Feten einbezogen, bei denen vor dem Abbruch eine anatomische Untersuchung durch einen in der Fetalsonografie geübten Geburtshelfer durchgeführt wurde und bei denen fetale Autopsiebefunde vorlagen. Die Fälle wurden durch die Datenbank unserer Sonografieabteilung zur „Registrierung von Fehlbildungen“ ermittelt. Die Sensitivität und Spezifität der Sonografie wurde für jedes Organsystem berechnet. Zur Abschätzung der Übereinstimmung von Ultraschall- und Autopsiebefunden wurden die Fälle einer der vier Kategorien zugewiesen, je nach Grad der Übereinstimmung der Befunde: Solche mit völliger, sich fast entsprechender und nur teilweiser Übereinstimmung sowie nicht bestätigte Ultraschallbefunde. ERGEBNISSE:Die Einschlusskriterien erfüllten 71 von 95 Schwangerschaftsabbrüchen aufgrund fetaler Anomalien und bildeten somit unsere Studienpopulation. Die Sensitivität der Sonografie in Bezug auf Malformationen des Gehirns und Wirbelsäule betrug 100 % (27/27) und in Bezug auf Anomalien der inneren Organe (einschließlich der Fehlbildungen des Urogenital- und Magen-Darm-Systems, der Bauchdecke und des Diaphragmas) 91 % (31/33). Die entsprechende Rate für Anomalien des Herz-Kreislauf-Systems betrug 63 % (17/27) und für die des Skelettsystems 71 % (25/35). Die niedrigste Spezifität wurde für Malformationen des zentralen Nervensystems (33/38, 87 %) und der inneren Organe (39/44, 89 %) ermittelt. Eine völlige Übereinstimmung von Ultraschall- und Autopsiebefunden wurde in 44 % (31/71) und eine sich fast entsprechende Übereinstimmung in 46 % (33/71) aller Fälle gefunden. Bei beinahe 10 % (7/71) der Schwangerschaften konnten die Ultraschallbefunde nur teilweise beziehungsweise gar nicht durch die Autopsie bestätigt werden. In einem Fall mit diskrepanten Ultraschall- und Autopsiebefunden kann angenommen werden, dass die Schwangere die Entscheidung für einen Abbruch vermutlich aufgrund der fehlerhaften Interpretation des Ultraschallbefundes fällte. SCHLUSSFOLGERUNG:Obwohl die Übereinstimmung von Ultraschall- und Autopsiebefunden vom klinischen Standpunkt betrachtet akzeptierbar schien, war sie bezüglich der genauen Beschreibung der Fehlbildungen bei weitem nicht perfekt. Die Trefferquoten beim Herz-Kreislauf- und Skelettsystem waren suboptimal.

背景与目标：

BACKGROUND & AIMS: :A 31-year-old woman complained of dyspnea and orthopnea at 38 weeks of gestation. A grade 3/6 pansystolic murmur was heard, and echocardiography revealed severe mitral regurgitation with a hyperechoic obstacle on the posterior mitral valve leaflet, consistent with a diagnosis of acute heart failure due to a ruptured chordae tendineae or an infectious endocarditis. An emergency cesarean section was performed under general anesthesia. A male infant was born weighing 2928 g with Apgar scores of 7 and 8 at 1 and 5 min, respectively. The patient was managed in the intensive care unit and underwent open-heart surgery for mitral valve repair on postpartum day 3. The two chordal tendineae appeared torn and frail, and a mitral annuloplasty was performed. No finding of infectious endocarditis was observed. Because it is a dramatic and life-threatening clinical situation, proper diagnosis and treatment in the intensive care unit assure a good outcome for both mother and fetus.

背景与目标： : 一名31岁的妇女在妊娠38周时抱怨呼吸困难和正呼吸。听到了3/6级的全收缩期杂音，超声心动图显示严重的二尖瓣反流，二尖瓣后叶上有高回声障碍，这与由于腱索破裂或感染性心内膜炎引起的急性心力衰竭的诊断一致。在全身麻醉下进行紧急剖宫产。出生时体重为2928  g的男婴，分别在1和5  min时Apgar评分为7和8。该患者在重症监护病房接受治疗，并于产后第3天接受心脏直视手术进行二尖瓣修复。两个腱索出现撕裂和脆弱，并进行了二尖瓣环成形术。未发现感染性心内膜炎。由于这是一个戏剧性的，危及生命的临床情况，因此在重症监护病房中进行适当的诊断和治疗可确保母亲和胎儿的良好结局。

BACKGROUND & AIMS: :The aim of this study was to investigate alterations in the leukocyte and differential leukocyte counts in different trimesters of pregnancy and the initial postpartum period. The study population consisted of 40,325 pregnant women. A full blood count and automated differential leukocyte count were performed and all the haemogram results in the different trimesters of pregnancy were recorded. Percentiles were calculated using statistical software. A total of 82,786 complete blood count evaluations were performed in 40,325 subjects from the 6th to 41st week of pregnancy and in the initial postpartum period. The leukocyte counts increased from the 1st to the 3rd trimester and peaked in the initial postpartum period. Our reference values for the total and differential leukocyte counts may assist clinicians in distinguishing between leukocytosis and pathological elevation of the white blood cell count during pregnancy and the initial postpartum period. Impact statement Pregnancy requires profound adaptation by multiple systems to accommodate the demands of the developing foetus. Similar to all other systems, many haematological changes occur during pregnancy. Studies of normal variation in leukocyte counts were insufficient to distinguish normal from abnormal leukocyte counts during pregnancy and in the initial postpartum period, due to small numbers of patients and a lack of differential leukocyte counts. Without reference leukocyte levels, infections may be more difficult to assess during pregnancy and in the postpartum period. In this study, we report the 3rd, 5th, 10th, 50th, 95th and 99th percentile values for the total and differential leukocyte counts according to trimester in normal pregnancy and the initial postpartum period. Our reference values for the total and differential leukocyte counts in each trimester and the initial postpartum period may assist clinicians in distinguishing between normal leukocytosis and pathological elevation of the white blood cell count during pregnancy and the initial postpartum period. Our results may prevent misdiagnosis of physiological elevated leukocytes as bacterial infection that leads to unnecessary medication use that may compromise the foetus.

背景与目标： : 这项研究的目的是调查妊娠不同三个月和产后初期白细胞和白细胞计数差异的变化。研究人群由40,325名孕妇组成。进行了全血细胞计数和自动差异白细胞计数，并记录了妊娠不同三个月的所有血象结果。使用统计软件计算百分位数。从怀孕的第6周至第41周和产后初期，对40,325名受试者进行了总共82,786次全血细胞计数评估。白细胞计数从第1个月到第3个月增加，并在产后初期达到峰值。我们的总白细胞计数和差异白细胞计数参考值可以帮助临床医生区分白细胞增多和妊娠和产后初期白细胞计数的病理升高。影响声明怀孕需要多个系统进行深刻的适应，以适应发育中的胎儿的需求。与所有其他系统相似，许多血液学变化发生在怀孕期间。由于患者人数少且缺乏差异的白细胞计数，对白细胞计数正常变化的研究不足以区分妊娠期间和产后初期的正常白细胞计数与异常白细胞计数。如果没有参考白细胞水平，则在怀孕期间和产后期间可能更难评估感染。在这项研究中，我们根据正常妊娠和产后初期的三个月报告了总白细胞计数和差异白细胞计数的第3、5、10、50、95和99个百分位数值。我们在每个孕期和产后初期的总白细胞计数和差异白细胞计数的参考值可以帮助临床医生区分正常的白细胞增多和妊娠和产后初期的白细胞计数的病理升高。我们的结果可以防止将生理性白细胞升高误诊为细菌感染，从而导致不必要的药物使用，从而可能损害胎儿。

BACKGROUND & AIMS: BACKGROUND:The recent spread of avian influenza in wild birds and poultry may be a precursor to the emergence of a 1918-like human pandemic. Therefore, stockpiles of human pre-pandemic vaccine (targeted at avian strains) are being considered. For many countries, the principal constraint for these vaccine stockpiles will be the total mass of antigen maintained. We tested the hypothesis that lower individual doses (i.e., less than the recommended dose for maximum protection) may provide substantial extra community-level benefits because they would permit wider vaccine coverage for a given total size of antigen stockpile. METHODS AND FINDINGS:We used a mathematical model to predict infection attack rates under different policies. The model incorporated both an individual's response to vaccination at different doses and the process of person-to-person transmission of pandemic influenza. We found that substantial reductions in the attack rate are likely if vaccines are given to more people at lower doses. These results are applicable to all three vaccine candidates for which data are available. As a guide to the magnitude of the effect, we simulated epidemics based on historical studies of immunogenicity. For example, for one of the vaccines for which data are available, the attack rate would drop from 67.6% to 58.7% if 160 out of the total US population of 300 million were given an optimal dose rather than 20 out of 300 million given the maximally protective dose (as promulgated in the US National Pandemic Preparedness Plan). Our results are conservative with respect to a number of alternative assumptions about the precise nature of vaccine protection. We also considered a model variant that includes a single high-risk subgroup representing children. For smaller stockpile sizes that allow vaccine to be offered only to the high-risk group at the optimal dose, the predicted benefits of using the homogenous model formed a lower bound in the presence of a risk group, even when the high-risk group was twice as infective and twice as susceptible. CONCLUSIONS:In addition to individual-level protection (i.e., vaccine efficacy), the population-level implications of pre-pandemic vaccine programs should be considered when deciding on stockpile size and dose. Our results suggest that a lower vaccine dose may be justified in order to increase population coverage, thereby reducing the infection attack rate overall.

背景与目标：