Premature labor, Part II: Management.

BACKGROUND: As the second paper in a two-part series on preterm labor, this article discusses the management of preterm labor as it relates to risk reduction, tocolytic therapy, corticosteroids, and antibiotics. METHODS: Published literature on the management of preterm labor was reviewed by searching MEDLINE files from 1983 to the present, using the terms "preterm labor," "premature labor," "preterm labor and antibiotics," "tocolytic agents," "tocolysis," "betamethasone," and "premature rupture of membranes." Additional references were obtained by cross-referencing bibliographies from available articles. RESULTS AND CONCLUSIONS: Effective management of preterm labor and birth begins with an assessment and reduction of risks for all pregnant women. In addition, pregnant women should be screened and appropriately treated for urologic and gynecologic infections (e.g., syphilis, gonorrhea, Chlamydia, and bacterial vaginosis). Women who are at high risk for preterm birth should be enrolled in a preterm birth prevention program that includes frequent contact with health professionals, patient education about the signs and symptoms of preterm labor, home monitoring, and regular cervical examinations. For women who develop preterm labor that does not require immediate delivery, recommended management strategies include reduced activity, early tocolytic therapy, corticosteroids for up to 34 weeks' gestation (both for women with intact and ruptured membranes), and antibiotics for known infections. Early studies also suggest that prophylactic antibiotics can be beneficial for women with idiopathic preterm labor or preterm premature rupture of membranes.     

Is older maternal age a risk factor for preterm birth and fetal growth restriction? A systematic review

To determine if there was an association between advancing maternal age and adverse pregnancy outcomes (preterm delivery and small-for-gestational-age births), a systematic review was conducted based on a comprehensive search of the literature from 1985 to 2002. Ten studies met the following inclusion criteria: (1) assessed risk factors for preterm birth by subtype (i.e., idiopathic preterm labor, preterm premature rupture of membranes) and small-for-gestational-age (SGA) birth (fetal growth restriction); (2) used acceptable definitions of these outcomes; (3) were published between January 1985 and December 2002; (4) were restricted to studies that have considered preterm birth due to idiopathic preterm labor or premature rupture of membranes or both; (5) were restricted to singleton live births; (6) were conducted in a developed country; and (7) were published in English. The majority of the studies reviewed found that older maternal age was associated with preterm birth. There is insufficient evidence to determine if older maternal age is an independent and direct risk factor for preterm birth and SGA birth, or a risk marker that exerts its influence on gestational age or birth weight or both through its association with age-dependent confounders. Future research is needed to quantify the independent and unconfounded impact of delayed childbearing on neonatal outcomes, as well as to identify the pathways involved.     

Is Older Maternal Age a Risk Factor for Preterm Birth and Fetal Growth Restriction? A SystematicReview

To determine if there was an association between advancing maternal age and adverse pregnancy outcomes (preterm delivery and small-for-gestational-age births), a systematic review was conducted based on a comprehensive search of the literature from 1985 to 2002. Ten studies met the following inclusion criteria: (1) assessed risk factors for preterm birth by subtype (i.e., idiopathic preterm labor, preterm premature rupture of membranes) and small-for-gestational-age (SGA) birth (fetal growth restriction); (2) used acceptable definitions of these outcomes; (3) were published between January 1985 and December 2002; (4) were restricted to studies that have considered preterm birth due to idiopathic preterm labor or premature rupture of membranes or both; (5) were restricted to singleton live births; (6) were conducted in a developed country; and (7) were published in English. The majority of the studies reviewed found that older maternal age was associated with preterm birth. There is insufficient evidence to determine if older maternal age is an independent and direct risk factor for preterm birth and SGA birth, or a risk marker that exerts its influence on gestational age or birth weight or both through its association with age-dependent confounders. Future research is needed to quantify the independent and unconfounded impact of delayed childbearing on neonatal outcomes, as well as to identify the pathways involved.     

Preterm birth subtypes among blacks and whites.

The differences in preterm birth between blacks and whites are poorly understood. Our study examined subtypes of moderately preterm delivery (34-36 completed weeks of gestation) and very preterm delivery (20-33 weeks) in blacks and whites using North Carolina birth certificate data for 1988-1989. We divided the causes of preterm birth into three categories: preterm premature rupture of the membranes, indication of pregnancy complication, and idiopathic preterm deliveries. The overall prevalence of preterm birth was 8.0% and 16.7% for whites and blacks, respectively. The entire gestational age distribution of blacks was shifted to earlier ages relative to whites. More highly educated blacks still had higher risks of moderately and very preterm deliveries than less educated whites. Multivariate analysis, controlling for other factors, showed that blacks had 3.3, 2.5, and 3.5 times the risk of whites to have preterm premature rupture of the membranes, complication-related, and idiopathic delivery, respectively, among very preterm births, and 1.6, 1.9, and 2.0 times the risk of whites for moderately preterm births of the same three types.     

基质金属蛋白酶-3在早产发动机制中的作用研究

目的:通过检测孕产妇血清及胎盘胎膜中的基质金属蛋白酶-3(MMP-3)水平,探讨其在宫缩发动及胎膜早破中的可能作用机制。方法:选择单胎、头位、初产妇280例作为研究对象,按孕周、胎膜是否破裂和是否临产分为7组:早产临产组、早产胎膜早破组、先兆早产组、足月临产组、足月胎膜早破组、妊娠28～36+6周无任何产兆组(未足月对照组,对照组Ⅰ)、足月妊娠无产兆择期剖宫产组(足月对照组,对照组Ⅱ)。用ELISA法检测孕妇血清中的MMP-3水平,用免疫组化SP法检测胎盘胎膜组织中的MMP-3表达情况。结果:血清MMP-3的平均水平为(212.58±63.03)ng/ml,早产临产组和早产胎膜早破组血清MMP-3水平均高于先兆早产组和对照组Ⅰ(P<0.05);足月临产组和足月胎膜早破组血清MMP-3水平均高于对照组Ⅱ(P<0.05);相关未足月组和足月组之间相比,早产临产组和足月临产组血清MMP-3水平比较差异有统计学意义(P<0.05)。胎盘MMP-3免疫积分在临产组及胎膜早破组升高(P<0.05);胎膜MMP-3免疫积分在早产组表达增加,在各胎膜早破组较同孕期临产组明显升高(P<0.05)。血清MMP-3水平与胎盘胎膜MMP-3水平呈正相关。结论:血清及胎盘胎膜中MMP-3的高表达可能参与早产的发动。     

Toll样受体4及肿瘤坏死因子α在早产儿外周血水平及其与早产儿脑损伤预后的关系

目的观察早产儿出生时外周血Toll样受体4(Toll-like receptor 4,TLR-4)、肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)的水平及校正胎龄6个月龄时智力发育测试(CDCC)结果,探讨其在早产发生机制中的作用及其与早产儿脑损伤预后的关系,为预防早产及对脑损伤早期干预提供依据。方法新生儿120例,分为:足月儿40例、胎膜早破早产儿40例和特发性早产儿40例。采用ELISA检测新生儿外周静脉血中TLR-4、TNF-α的水平,校正胎龄达6个月时做婴幼儿CDCC。结果两组早产儿血清TLR-4、TNF-α水平均高于足月新生儿组,差异有统计学意义(P0.05);两组早产儿血清TLR-4、TNF-α均呈正相关,差异有统计学意义(P0.01)。随访CDCC异常者出生时外周血清中TLR-4、TNF-α水平明显高于正常者水平,二者比较差异有统计学意义(P0.01)。结论早产儿血清TLR-4、TNF-α水平均高于足月新生儿,提示细胞因子TLR-4、TNF-α的激活与胎膜早破早产、特发性早产分娩发动机制密切相关;TLR-4、TNF-α呈正相关性,提示TLR-4可能作为上游因子通过激活细胞因子TNF-α而发挥促进早产分娩的作用。早产儿出生时外周血中TLR-4、TNF-α水平可作为早期判断脑损伤预后的指标。     

妊娠期糖尿病与早产亚型之间的关联研究

目的 探讨妊娠期糖尿病（GDM）与早产亚型之间的关联。方法 招募孕早、中期在安徽省安庆市立医院产前筛查的孕妇,进行基线调查和生物标本采集,随访孕妇至分娩或妊娠终止,通过医院电子病历系统、问卷调查等获取孕妇孕期情况、妊娠结局等信息,建设孕妇队列。采用log-binomial回归模型探讨GDM与早产［医源性早产和自发性早产（未足月胎膜早破和早产临产）］之间的关联;对于多个混杂因素,采用倾向性评分校正法构建模型计算调整后的关联。结果 在2 031例分娩单胎的孕妇中,GDM和早产的发生比例分别为10.0%（204例）和4.4%（90例）;其中,GDM组（n=204）孕妇发生医源性早产和自发性早产的比例分别为1.5%和5.9%,非GDM组（n=1 827）孕妇发生医源性早产、自发性早产的比例分别为0.9%和3.2%,两组自发性早产的比例差异有统计学意义（P=0.048）。进一步细化自发性早产亚型,结果显示GDM组发生未足月胎膜早破、早产临产的比例分别为4.9%和1.0%,非GDM组发生未足月胎膜早破、早产临产的比例分别为2.1%和1.1%。GDM孕妇发生未足月胎膜早破的风险是非GDM孕妇的2.34倍（aRR=2.34,95%CI：1.16~4.69）。结论 GDM可能增加未足月胎膜早破的发生风险,未发现GDM孕妇早产临产发生比例显著增加。     

6例双绒双胎妊娠中期选择性减胎后胎膜早破患者妊娠结局分析

目的：回顾性分析通过辅助生殖技术受孕的双绒毛膜双羊膜囊双胎（双绒双羊双胎）妊娠中期减胎后发生胎膜早破患者的妊娠结局,为临床妊娠中期胎膜早破患者的治疗提供一定的临床依据。方法：收集2012年1月—2018年2月在武汉大学人民医院生殖中心选择性减胎后发生胎膜早破的双绒双羊双胎妊娠患者6例,患者受孕方式为体外受精（IVF）或胞浆内单精子注射（ICSI）,绒毛膜性在妊娠早期超声诊断为双绒双羊双胎,孕12～16周接受选择性减胎。结果：6例患者均减胎成功,减灭的胎儿除了1例为右侧胎儿,1例为左下方胎儿,其余4例均为下方胎儿。减胎后胎膜早破均发生在减胎后的24 h内,所有患者均在减胎胎膜早破后8 d之内（2～8 d）停止阴道流液。整个妊娠期1例患者妊娠晚期羊水过少,1例因胎膜早破早产,1例合并妊娠期糖尿病,另3例患者无异常。除了胎膜早破早产患者分娩孕周为34+6周,其余均为足月分娩,其中有4例患者剖宫产,2例经阴道顺产。新生儿体质量为2 200～3 400 g,4名男婴,2名女婴,除早产儿合并肺部感染外,其余新生儿均无并发症。结论：辅助生殖技术受孕双绒双胎妊娠中期选择性减胎后胎膜早破患者可以建议期待治疗,其妊娠结局可能是令人满意的,然而仍需要大样本研究来证实。     

未足月胎膜早破后早产儿脑损伤的相关危险因素分析

目的:分析未足月胎膜早破后早产儿脑损伤的高危因素。方法:对2008年1月～2010年10月在医院产科出生且生后即转入新生儿科的未足月胎膜早破后早产儿及母亲的临床资料进行回顾性分析,按早产儿生后有无脑损伤分为脑损伤组与无脑损伤组。对患儿胎龄、出生体质量、性别、母亲有无绒毛膜羊膜炎、羊水指数、母亲产前应用激素、破膜时间、分娩方式、胎儿宫内窘迫、窒息复苏10个项目进行分析。结果:137例早产儿符合研究标准,未足月胎膜早破后早产儿脑损伤发生率24.8%。早产儿脑损伤危险因素Logistic回归分析按OR值排序,依次为胎龄、出生体重、窒息复苏及母亲绒毛膜羊膜炎。破膜时间长短与脑损伤无关。结论:未足月胎膜早破后早产儿脑损伤的发生与多因素有关,胎龄越小、体重越低脑损伤发生率越高,母亲绒毛膜羊膜炎及患儿生后有窒息复苏史也为早产儿脑损伤高危因素。     

早产影响因素的前瞻性队列研究

目的  分析中国早产的流行现状及危险因素,为早产的预防提供参考依据。 方法  本研究数据来源于中国孕产妇队列研究·协和项目(Chinese Pregnant Women Cohort Study, CPWCS),通过问卷调查和医院信息系统(hospital information system, HIS)收集孕妇基本情况和分娩结局。采用SPSS 26.0软件进行χ²检验和多因素Logistic回归分析模型分析。 结果  5 671名孕妇中发生早产的例数为295例,占5.2%,不同地区早产率差异无统计学意义(χ² =0.591, P=0.771)。多因素分析结果显示：高龄、糖尿病史、早产史、胎盘早剥、胎膜早破、胎儿宫内窘迫、妊娠期高血压以及双胎是早产的危险因素(均有P < 0.05),而在自然分娩的孕妇中,高龄(OR=2.90, 95% CI: 1.67~5.06, P < 0.001)、胎膜早破(OR=6.17, 95% CI: 4.21~9.06, P < 0.001)、双胎(OR=17.72, 95% CI: 3.23~97.25, P=0.001)是早产的主要危险因素。 结论  早产的影响因素较多,准确识别危险因素,为孕妇提供科学合理的健康教育和个性化的防治措施是预防早产的重要手段。     

孕妇沙眼衣原体感染的快速诊断方法研究进展

妊娠期感染沙眼衣原体后 ,可导致胎膜早破、早产、低体重儿甚至死胎。敏感性高且特异性强的快速诊断方法 ,不仅可以早期诊断沙眼衣原体感染 ,而且对控制本疾病的母婴传播及预防并发症的发生有重要作用。     

611例胎膜早破危险因素及妊娠结局的临床回顾性分析

目的 探讨胎膜早破的高危因素、分娩方式及对妊娠结局的影响.方法 回顾性分析2011年1月至2012年12月在山西医科大学第一医院住院分娩的611例胎膜早破孕妇的相关临床资料（本研究遵循的程序符合山西医科大学第一医院人体试验委员会制定的伦理学标准,得到该委员会批准,征得受试对象知情同意,并与之签署临床研究知情同意书）.结果 研究结果认为：①本院胎膜早破的发生率为15.1%（611/4 047）,其中未足月胎膜早破的发生率为2.6%（104/4 047）,足月胎膜早破发生率为12.5%（507/4 047）.②导致胎膜早破的高危因素主要为生殖道感染、流产或引产史与宫腔内压力增加（因巨大儿、双胎与多胎妊娠、羊水过多所致）,妊娠期高血压疾病等.③足月胎膜早破的阴道分娩率高于未足月胎膜早破,而足月胎膜早破的剖宫产率低于未足月胎膜早破.足月胎膜早破的胎儿窘迫及新生儿窒息的发生率低于未足月胎膜早破,且差异有统计学意义（P〈0.05）.结论 胎膜早破可对母婴造成不良影响,应重视胎膜早破的高危因素,加强孕前和孕期保健,降低胎膜早破的发生率,并对不同孕周胎膜早破患者加强临床监护,给予正确处理,减少母婴并发症.     

Maternal asthma and risk of preterm delivery

PURPOSE: We studied the relation between maternal history of asthma and preterm delivery. METHODS: The 312 preterm delivery cases, studied in aggregate, and in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery), were compared with 424 randomly selected women who delivered at term. Maternal medical records provided information on maternal lifetime asthma status, pregnancy outcome, and sociodemographic characteristics. Using multivariate logistic regression, we derived maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Maternal history of asthma was associated with an increased risk of preterm delivery overall (OR = 2.37; 95% CI 1.15-4.88). Analyses of preterm delivery sub-groups indicated that maternal history of asthma was associated with at least a doubling in risk of spontaneous preterm labor (OR = 2.35; 95% CI 0.84-6.58) and medically induced preterm delivery (OR = 2.69; 95% CI 1.11-6.53), though only the latter approached statistical significance. There was some evidence of a modest association between maternal asthma and risk of preterm premature rupture of membranes (OR = 1.63; 95% CI 0.50-5.33). CONCLUSIONS: These results support the hypothesis that maternal asthma is associated with an increased risk of preterm labor and delivery.     

胎膜早破430例临床分析

目的:探讨胎膜早破的发病与分娩方式、对母儿结局的影响及其早期合理的临床处理措施。方法:回顾性分析2004年9月～2007年12月就诊的874例无妊娠合并症及并发症的产妇资料(其中胎膜早破者430例,胎膜未破者444例作为对照组),比较其最终的分娩方式以及母儿的结局。结果:胎膜早破组的早产率为18.3%、剖宫产率为8.2%、新生儿窒息率为4.1%,对照组早产率为4.6%、剖宫产率为2.3%、新生儿窒息率为0.8%,两组间数据在统计学上有显著性差异(P<0.05)。结论:胎膜早破与难产的关系密切。应重视胎膜早破发生的原因,加强孕前和孕期保健,降低胎膜早破发生率。并对不同孕周的胎膜早破患者加强临床监护,给予正确处理,减少母儿并发症。     

胎膜早破188例临床分析

目的 探讨胎膜早破的发病因素和母婴并发症以及临床处理策略.方法 对2010年2月～2011年2月期间188例胎膜早破的临床病例特点进行回顾性分析,并随机抽取同期正常分娩的200例作为对照组.结果 病因方面胎膜早破组感染、胎位异常、头盆不称、宫颈内口松驰、子宫畸形等明显高于对照组;妊娠结局方面胎膜早破组剖宫产、早产、产后出血、产褥感染、新生儿窒息、新生儿肺炎等明显高于对照组.结论 胎膜早破发病因素有自身特点,与难产互为因果,而且增加母要的并发症,对不同特点的胎膜早破应采取不同的治疗方法.     

Racial differences in the patterns of preterm delivery in central North Carolina, USA

Summary. In order to assess racial differences in rates of idiopathic preterm labour, preterm premature rupture of membranes, and medically indicated preterm delivery, the authors analysed data on 388 preterm (< 37 completed weeks of gestation) births (7.9% of all births) occurring between 1 September 1988 and 31 August 1989, in three central North Carolina counties. The crude relative risk (RR) of preterm birth among black women compared with white women was 2.6 [95% confidence interval (CI) 2.1, 3.1]. With adjustment for age, gravidity, marital status, education, and county of residence, the estimated relative risk for black women compared with white women was 2.1 (95% CI 1.1,4.1) for medically indicated preterm delivery, 1.6 (95% CI 1.1,2.3) for preterm birth as a result of preterm labour, and 1.9 (95% CI 1.2,3.1) for preterm premature rupture of membranes. Compared with white women, black women were at the highest risk of a preterm birth before 34 weeks of gestation (RR = 2.9; 95% CI 1.8, 4.7). The risk of medically indicated preterm delivery at 36 weeks was considerably higher for black women than for white women (RR = 3.4; 95% CI 1.1,10.2). For a better understanding and ultimately a reduction of the risk for preterm delivery among black women, investigation of specific aetiological pathways and gestational age groups may be required.     

宫颈环形电切术后妊娠及分娩结局的临床分析

目的探讨对宫颈上皮内瘤变(cervical intraepithelial neoplasia,CIN)患者实施宫颈环形电切术(loop electrical excision procedure,LEEP)后妊娠及分娩结局的相关因素。方法选择2007年7月至2012年7月南方医科大学附属中山市博爱医院收治的120例因CIN行宫颈LEEP且有生育要求的患者作为观察组,随机抽取同期孕前门诊的120例无宫颈手术且曾患宫颈炎的妇女作为对照组,对两组对象的妊娠和分娩结局及围产儿情况进行分析。结果观察组剖宫产率、早产率和早产胎膜早破(preterm premature rupture of membranes,PPROM)发生率均高于对照组(P0.05),观察组新生儿出生体重低于对照组(P0.05);观察组术后宫颈长度缩短、宫颈管宽度增加(P0.05)。结论宫颈LEEP可引起宫颈松弛,术后可增加孕妇早产、PPROM等不良妊娠和分娩结局的发生率。     

因不同情况行宫颈环形电切术后的孕妇妊娠结局比较

目的探讨因不同情况行宫颈环形电切术(loop electrosurgical excision procedure,LEEP)后的孕妇妊娠结局。方法回顾性分析解放军五三七医院2009年1月至2015年5月收治的曾行宫颈LEEP术的孕妇267人的临床资料,因"宫颈柱状上皮异位"行LEEP术的225人为治疗A组,因"宫颈上皮内瘤变"(cervical intraepithelial neoplasia,CIN)行LEEP术的42人为治疗B组,同期未行宫颈物理治疗的100名孕妇为对照组,比较3组的先兆流产率、早产率、胎膜早破发生率、顺产率、分娩孕周、新生儿体重、产后出血发生率及顺产时宫颈裂伤发生率。结果 3组在先兆流产率、早产率、胎膜早破发生率、顺产率、分娩孕周、新生儿体重、产后出血发生率及顺产时宫颈裂伤发生率方面差异均无统计学意义(P0.05)。结论 "宫颈柱状上皮异位"和CIN患者行LEEP术后不会影响妊娠结局。     

Premature labor, Part I: Risk assessment, etiologic factors, and diagnosis.

BACKGROUND: This paper, the first of a two-part series on premature labor, reviews the recent literature on the causes of and risk factors for preterm labor and methods of diagnosis. METHODS: A review of the literature on risk determination and diagnosis of preterm labor was conducted by searching MEDLINE files from 1983 to the present, using the key terms "preterm labor," "premature labor," "preterm labor and infection," and "uterine monitoring." Additional references were accessed by cross-referencing the bibliographies of the articles obtained through this search. RESULTS AND CONCLUSIONS: Risk factors for preterm labor, which include items related to the pregnant woman's demographic characteristics, history, daily habits, and current pregnancy, have been combined into scoring systems commonly used by clinicians and researchers to single out women at risk for preterm delivery. When such systems are tested in obstetric populations, results show variable success in predicting preterm labor or birth. These inconsistent results could be due, in part, to important factors that have often been omitted from scoring systems, such as chemical abuse, poor nutrition, little social support, demanding work, multiple sexual partners, past or current sexually transmitted diseases, and other gynecologic infections. Women who are considered high risk for preterm labor can benefit from participating in preterm birth prevention programs that incorporate home monitoring, patient education regarding the signs and symptoms of preterm labor, frequent contacts with health professionals, and cervical examinations.     

Influence of smoking during pregnancy on children's health--overview of epidemiologic studies

The association between maternal smoking and retarded maternal condition and birth outcome is well know. Smoking during pregnancy increases risk of spontaneous abortion, placenta previa, abruptio placenta, preterm premature rupture of membranes, stillbirth, preterm delivery and sudden infant death syndrome. The recently conducted studies also indicate that prenatal exposure to tobacco smoke is a risk factor for respiratory infections, asthma, allergy, childhood cancer, and it has neurobehavioral consequences regarding children's health. The risk for most of these conditions has been found to increase with the number of cigarettes smoked. On the other hand women who stopped smoking during pregnancy are at lower risk for most of those pathologies.