肩难产发生的危险因素和临床特征的多中心分析

目的 探讨肩难产发生的危险因素和临床特征.方法 收集2008年1月至2013年9月,广州医科大学附属第三医院等5家医院住院的足月妊娠、单胎、头位并经阴道分娩的产妇共44 580例,其中发生肩难产116例(肩难产组),其余未发生肩难产者为对照组.对两组产妇的临床资料进行回顾性分析,包括年龄、身高、孕前体质指数(BMI)、孕期体质量增重值、孕周、孕次、产次、宫高、腹围、既往肩难产病史、分娩巨大儿、妊娠期糖尿病、糖尿病合并妊娠、过期妊娠及产程情况.结果 (1)44 580例产妇中发生肩难产116例,发生率为0.260％(116/44 580).肩难产组产妇年龄、孕前BMI、孕期体质量增重值明显高于对照组,两组比较,差异均有统计学意义(P＜0.01);两组产妇身高、孕周、孕产次、宫高及腹围分别比较,差异均无统计学意义(P＞0.05).(2)肩难产组产妇有肩难产病史(11.21％,13/116)、分娩巨大儿(13.79％,16/116)、糖尿病合并妊娠(7.76％,9/116)、过期妊娠(10.34％,12/116)、最大加速期延长(8.62％,10/116)及第二产程延长(7.76％,9/116)的发生率,分别与对照组[分别为(1.43％,636/44 464)、(1.48％,658/44 464)、(0.57％,252/44 464)、(1.15％,513/44 464)、(0.72％,322/44 464)、(0.65％,289/44 464)]比较,差异均有统计学意义(P＜0.05).(3)logistic回归分析显示,产妇年龄＞35岁(OR=1.116,95％CI为1.022～2.445)、孕前BMI＞27 kg/m2(OR=1.893,95％ CI为1.358～2.228)、孕期体质量增重值(＞20 kg)(OR=2.031,95％CI为1.749～ 3.231)、肩难产病史(OR=2.138,95％ CI为1.564～ 3.853)、分娩巨大儿(OR=3.276,95％CI为2.315～ 4.638)、糖尿病合并妊娠(OR=3.261,95％CI为2.237～ 4.943)、过期妊娠(OR=1.473,95％CI为1.003～ 2.721)、最大加速期延长(OR=2.022,95％CI为1.681～ 3.732)及第二产程延长(OR=1.943,95％CI为1.285～ 3.215),以上各项P值均＜0.05,是肩难产发生的危险因素.结论 高龄孕产妇(年龄＞35岁)、孕前BMI＞27 kg/m2、孕期体质量增重＞20 kg、肩难产病史、分娩巨大儿、糖尿病合并妊娠、过期妊娠、最大加速期延长及第二产程延长是肩难产发生的危险因素及临床特征.     

妊娠期糖尿病患者分娩巨大儿的危险因素分析

目的 探讨妊娠期糖尿病(GDM)患者分娩巨大儿的危险因素,为预防巨大儿的发生提供科学依据。方法 选取669例分娩的GDM患者,根据新生儿体重分为巨大儿组(100例)与非巨大儿组(569例)。回顾性分析患者的临床资料,采用多因素Logistic回归分析GDM患者分娩巨大儿发生的危险因素。结果 两组患者的孕前体重、分娩孕周、胎儿体重、口服葡萄糖耐量试验(OGTT)、糖化血红蛋白(HbA1c)、分娩方式、孕前体质量指数(BMI)、孕期体重增长比较,差异均有统计学意义(P<0.05)。多因素logistic回归分析结果显示孕前超重、肥胖、孕期增重过多、孕期HbA1c≥5.5%是分娩巨大儿的危险因素(P<0.05)。结论 GDM患者孕前超重肥胖、孕期体重增长过多及HbA1c控制不理想均可增加分娩巨大儿的风险,临床中应采取针对性的预防措施以降低巨大儿发生率。     

孕妇体质量及其他因素与分娩巨大儿的相关性研究

目的:探讨孕妇孕前和孕期体质量及有关因素与分娩巨大儿的相关性,为其预防提供指导。方法:选择2013年1月1日至2014年12月31日在四川大学华西第二医院住院分娩符合纳入标准的孕产妇10044例,其中分娩巨大儿466例,非巨大儿9578例。采用Logistics回归分析孕妇体质量及其他因素(妊娠期糖尿病、分娩巨大儿史、多胎妊娠等)与分娩巨大儿的相关性及不同BMI分类与分娩巨大儿的相关性。结果:(1)孕前BMI、孕期总体质量增长、妊娠期糖尿病及既往分娩过巨大儿是分娩巨大儿的独立危险因素(P0.05);多胎妊娠是分娩巨大儿的保护因素(P0.05)。(2)通过BMI分层后,对于孕前BMI正常者,孕期体质量增长过少和多胎妊娠是分娩巨大儿的保护因素(P0.05);孕期总体质量增长、孕期体质量增长过多、有巨大儿分娩史是分娩巨大儿的独立危险因素(P0.05)。对于孕前体质量过轻者,孕期总体质量增长和孕期体质量增长过多是分娩巨大儿独立危险因素(P0.05)。对于孕前超重的孕妇,孕期总体质量增长和妊娠期糖尿病是分娩巨大儿独立危险因素(P0.05)。结论:孕前BMI过高、孕期体质量增长过多、发生妊娠期糖尿病及既往分娩巨大儿史均可使再次妊娠发生巨大儿的风险明显增高;孕前不同BMI孕妇其分娩巨大儿的危险因素有不同,孕期体质量增长过多可能增加孕前偏瘦和体质量正常孕妇巨大儿的发生风险。     

新生儿血管瘤的高危因素

目的 探讨新生儿血管瘤发生的高危因素.方法 采用调查问卷的方法调查2009年1月1日至2011年12月31日在北京中日友好医院预防保健科建立《母子保健档案》的孕妇及其新生儿,调查内容包括孕母基本信息、围产期因素以及社会经济和环境因素.新生儿体检时若明确诊断血管瘤,对患处进行拍照,记录血管瘤部位及大小.采用单因素和多因素Logistic回归分析新生儿血管瘤的高危因素.结果 共回收有效问卷1998份,确诊新生儿血管瘤患儿94例,发生率为4.7％.多因素Logistic回归分析显示,新生儿血管瘤的危险因素为母亲孕龄≥30岁(OR=2.687,95％CI:1.615～4.472,P=0.000)、孕次≥2次(OR=1.730,95％CI:1.032～2.901,P=0.038)、新生儿性别(女)(OR=1.855,95％CI:1.187～2.899,P=0.007)、先兆流产(OR=3.135,95％CI:1.487～6.609,P=0.003)、羊膜腔穿刺(OR=2.754,95％CI:1.278～5.938,P=0.010)、血管瘤家族史(OR=2.978,95％CI:1.127～4.049,P=0.032)和视频显示终端暴露＞45 h/周(OR=3.166,95％CI:2.027～4.944,P=0.000).结论 新生儿血管瘤发生的高危因素可能为母亲年龄、多次妊娠、女婴、先兆流产、羊膜腔穿刺、家族史和长时间视频显示终端暴露.     

孕前体质指数及孕期体重增长对妊娠过程及结局的影响

目的:探讨孕前体质指数(BMI)及孕期体重增长(GWG)与妊娠合并疾病及不良结局的关系。方法:回顾分析于复旦大学附属妇产科医院产科门诊定期产前检查并住院分娩的3541例足月单胎初产妇的临床资料。将产妇按孕前体质指数(BMI)和不同孕期体重增长(GWG)分组,采用logistic多因素回归分析孕前体质指数及孕期体重增长与妊娠合并疾病及结局的关系。结果:孕妇孕期体重平均增加(16.0±4.9)kg,新生儿平均出生体重(3341.6±425.9)g,低出生体重儿和巨大儿分别占2.1%及5.1%。根据IOM推荐孕期GWG分组,GWG过低、过高组孕妇与正常孕妇的巨大儿、剖宫产数、早产发生率比较,差异有统计学意义(P0.05)。孕前超重、肥胖能增加妊娠期糖尿病(OR=2.7,2.3)、妊娠期高血压疾病(OR=5.4,OR=7.7)、巨大儿(OR=1.6,OR=8.9)、剖宫产(OR=1.4,OR=1.7)的发生风险,而GWG过高增加剖宫产的发生风险(OR=1.5)。结论:孕前BMI不仅影响妊娠合并疾病的发生,也与妊娠结局密切相关。临床上应特别重视孕前宣教及体检,建议育龄期妇女达到合适的体质指数后怀孕。孕期过度体重增长增大了不良妊娠结局(巨大儿、剖宫产)的发生率,临床上可参照IOM推荐体重增长范围进行孕妇体重控制,加强孕期的健康教育和体重随访。同时建议利用大数据多方调研,得出适合中国各地区的孕期体重参考标准。     

肩难产综合预防措施的荟萃分析

目的 探讨肩难产的综合预防措施.方法 计算机检索2014年5月以前的PubMed数据库、美国EBSCO数据库、荷兰医学文摘数据库、Cochrane图书馆数据库,以“shoulder dystocia and prevention”为主题词检索英文文献.对检索到的文献进行质量评价,文献研究类型仅限于随机对照临床试验(RCT)研究;研究对象为经阴道分娩产妇,干预措施包括孕期管理、预防性引产、预防性剖宫产术,预防性肩难产处理.纳入的文献采用RevMan 5.1软件进行荟萃分析,以肩难产发生率作为终点指标.结果 共有16篇英文文献纳入荟萃分析,发表时间为1993-2009年.(1)对妊娠期糖尿病(GDM)孕妇的孕期干预:有2篇文献比较了GDM孕妇的孕期干预(干预组)与不干预(不干预组)对肩难产发生率的影响,结果显示,干预组肩难产发生率显著低于不干预组(OR=0.40,95％ CI为0.21～0.75,P=0.004).(2)对GDM孕妇的孕期严格干预:5篇文献比较了GDM孕妇的孕期严格干预(饮食控制+胰岛素应用;严格干预组)与不严格干预(单纯饮食控制等;不严格干预组)对肩难产发生率的影响,结果显示,严格干预组肩难产发生率显著低于不严格干预组(OR=0.29,95％CI为0.11～ 0.73,P=0.009).(3)非糖尿病孕妇可疑巨大儿者引产:有4篇文献比较了非糖尿病孕妇可疑巨大儿者提前引产(提前引产组)对肩难产发生的影响,结果显示,提前引产组肩难产发生率与对照组比较,差异无统计学意义(OR=0.85,95％CI为0.41～ 1.75,P=0.660).(4)GDM孕妇引产:有2篇文献比较了GDM孕妇提前引产(孕38～ 39周;提前引产组)对肩难产发生的影响,结果显示,提前引产组肩难产发生率与对照组比较,差异有统计学意义(OR=0.18,95％CI为0.03～ 0.97,P=0.050);只与对照组中孕40周以后分娩者比较,提前引产组肩难产发生率显著低于对照组(OR=0.13,95％ CI为0.02～ 0.75,P=0.020).(5)GDM孕妇可疑巨大儿者提前终止妊娠:仅有1篇文献比较了GDM孕妇中可疑巨大儿者提前终止妊娠(提前终止妊娠)对肩难产发生率的影响,结果显示,提前终止妊娠组的肩难产发生率与对照组比较,差异有统计学意义(OR=0.34,95％CI为0.12～ 0.99,P=0.050).(6)产时预防性干预(产时干预组)对肩难产发生率的影响:有2篇文献比较了产时胎头娩出后行预防性干预对肩难产发生率的影响,结果显示,产时干预组肩难产发生率与对照组比较,差异无统计学意义(OR=0.44,95％CI为0.16～ 1.18,P=0.100).结论 对有肩难产高危因素的孕妇适当进行临床措施的干预,可明显降低肩难产的发生率.     

巨大儿高危因素的回顾性分析

目的通过对1638例妊娠资料的回顾性病例对照研究,探讨与巨大儿发生相关的高危因素的可能指标。方法收集2006年1月至2011年8月在四川大学华西第二医院住院分娩的足月单胎巨大儿838例作为研究对象,正常体重儿800例作为对照组,回顾性分析巨大儿发生的独立危险因素。结果巨大儿发生的独立危险因素为孕期增重18.25 kg、孕前BMI24.22 kg/m~2、产次1次、GDM、年龄29.5岁、男胎。结论孕期增重18.25 kg、孕前BMI24.22 kg/m~2、产次1次、GDM、年龄29.5岁、男胎增加巨大儿发生的风险。     

巨大儿孕妇孕期体重的动态分析

目的:探讨孕妇孕期增重及各孕期体重增加速度与分娩巨大儿的相关性,以冀开展有针对性的孕期管理,降低巨大儿的发生率。方法:回顾分析106例巨大儿和109例正常体重出生儿(对照组)母亲的孕前体重及孕期体重变化。结果:巨大儿组孕妇孕前体重,孕前BMI,孕期增重均高于对照组(P<0.01),两组孕妇体重增长速度最快时期均为孕20~30周,巨大儿组在孕20~30周及孕30周~分娩两期体重增速均高于对照组(P<0.01)。结论:巨大儿发生与孕妇孕前体重,孕前BMI,孕期增重等因素相关,应密切观察孕妇各孕期体重的变化,尤其是孕中晚期。     

孕前体重指数和孕期增重对妊娠结局的影响

目的 探讨孕前体重指数(body mass index,BMI)和孕期增重对妊娠结局的影响,为制定孕期体重分级管理方案提供依据. 方法 研究对象为2009年1月至2010年4月在南京大学医学院附属鼓楼医院产科定期产前检查的健康单胎妊娠孕妇2409例.根据孕前BMI分为孕前体重过低(BMI＜ 18.5)、体重正常(BMI 18.5～)、超重和肥胖(BMI≥24.0)3组.孕期增重计算方法为分娩前最高体重减去孕前体重.将孕前体重过低和体重正常的孕产妇,分别按孕期增重＜10 kg、10 kg～、≥15 kg分为3个亚组;孕前超重和肥胖的孕产妇,按孕期增重＜5 kg、5 kg～、10 kg～、≥15 kg分为4个亚组.记录分娩孕周、分娩方式、新生儿出生体重和Apgar评分,以及妊娠期高血压疾病、妊娠期糖尿病、巨大儿、胎儿生长受限及早产的发生率.统计学分析采用t检验、方差分析、Student-Newman-Keuls检验、x2检验或Fisher精确概率法. 结果 (1)2409例孕妇中,孕前体重过低、体重正常、超重和肥胖组的构成比分别为18.5％(445例)、69.9％(1685例)和11.6％(279例).孕前超重和肥胖组HDP、GDM和巨大儿发生率、剖宫产率分别为12.9％(36例)、17.9％(50例)、13.6％(38例)和52.3％(146例),均高于孕前体重过低组[3.4％(15例)、4.3％(19例)、3.8％(17例)和25.8％(115例),x2分别为23.8、37.1、23.5和50.2,P＜0.05]和体重正常组[5.5％(92例)、7.8％(132例)、7.8％(132例)和31.6％(532例),x2分别为21.8、29.0、10.1和3.4,P＜0.05].(2)孕前体重正常者,孕期增重＜10 kg亚组FGR发生率和早产率分别为3.5％(4/115)和8.7％(10/115),高于增重10 kg～亚组[0.7％(4/548)和3.3％(18/548),x2分别为6.0和6.9,P＜0.05]和≥15 kg亚组[0.8％(8/1022)和3.6％(37/1022),x2分别为7.2和6.7,P＜0.05].增重≥15 kg亚组巨大儿发生率和剖宫产率分别为10.7％(109/1022)和34.5％(353/1022),高于增重＜10 kg亚组[3.5％(4/115)和32.2％(37/115),x2分别为6.0和63.0,P＜0.05]和10 kg～亚组[3.5％(19/548)和25.9％(142/548),x2分别为24.7和31.0,P＜0.05].(3)孕前超重和肥胖者,孕期增重不同的4个亚组妊娠并发症和妊娠结局比较,差异均无统计学意义(P＞0.05). 结论 孕前超重或肥胖者妊娠并发症和剖宫产的风险增加.孕前体重正常者如果孕期增重过高或过低,也可能增加妊娠并发症风险,孕期增重控制在10～15 kg较为适宜.     

分娩方式对产后妇女粪失禁及尿失禁的影响

目的 调查女性产后粪失禁和尿失禁的发生率及其相关因素.方法 电话随访2006年10月1日至2007年9月30日在北京大学第一医院妇产科分娩的产妇,共纳入2012例妇女,收集其产后6个月内粪失禁和尿失禁的症状.采用Logistic回归法分析分娩方式与尿失禁和粪失禁的关系.结果 (1)参与调查的2012例产后妇女,14例(0.70％)有粪失禁症状.Logistic回归分析显示,粪失禁与阴道产钳助产(OR=20.09,95％ CI:3.64～110.90,P=0.000)和会阴侧切术分娩相关(OR=6.11,95％ CI:1.29～28.80,P=0.024).(2)2012例妇女中产后尿失禁、压力性尿失禁(stress urinary incontinence,SUI)、急迫性尿失禁(urge urinary incontinence,UUI)、混合性尿失禁(mixed urinary incontinence,MUI)的发病率分别为10.04％(202例)、8.15％ (164例)、0.94％(19例)和0.94％(19例).Logistic回归分析显示,与SUI相关的因素有:母亲年龄(OR=1.07,95％ CI:1.04～1.11,P=0.000)、母亲分娩前体重(OR=1.04,95％CI:1.02～1.06,P=0.001)、新生儿头围(OR=1.20,95％ CI:1.05～1.39,P=0.010)、会阴侧切术分娩(OR=4.96,95％ CI:3.05～8.07,P=0.0005)、阴道自然分娩(OR=5.22,95％ CI:2.53～10.76,P=0.000)和阴道产钳助产(OR=9.20,95％ CI:4.07～20.79,P=0.000).与UUI相关的因素有:产妇分娩前体重(OR=1.51,95％CI:1.12～2.05,P=0.008).与MUI相关的因素有:产妇分娩前体重(OR=1.06,95％ CI:1.00～1.11,P=0.049)、第二产程时限(OR=1.01,95％ CI:1.00～1.03,P=0.010)、会阴侧切术分娩(OR=7.76,95％ CI:1.42～42.52,P=0.017)和阴道产钳助产(OR=15.21,95％ CI:1.61～143.44,P=0.018).(3)产后4d和产后42 d SUI的发病率较高分别为7.95％和9.10％.结论 (1)本院产后妇女粪失禁和尿失禁的发病率较先前报道的其他地区的发病率低.(2)阴道分娩是妇女产后粪失禁和尿失禁发生的高危因素,特别是阴道产钳助产和会阴侧切术分娩.(3)母亲的年龄、分娩前体重、新生儿出生时头围、阴道自然分娩、产钳助产、会阴侧切术是发生尿失禁的高危因素.     

Differences in female and male perception of information and decision-making in single-embryo transfer in in vitro fertilization in Sweden

Purpose The aim of this study was to evaluate the information and the factors that contribute to the decision to accept and choose single embryo transfer (SET) in females and males. Materials and methods Fifty-four females and males undergoing SET were interviewed separately using a structured questionnaire. Results The women were significantly more satisfied with the information than the men (odds ratio 3.3), but the decision to accept SET was nevertheless more difficult for women (OR 3.1). Only one-third of both female and males were aware of the increased maternal risks with twin pregnancies. There was a tendency that the women who accepted SET had previous children, shorter duration of infertility, and were younger. Cryopreservation of embryos and a good pregnancy chance were important irrespective of gender. Conclusion The female needs more support to choose SET. The male needs better information and further involvement in decision-making. The females were more aware of the fetal risks, but the awareness of the increased maternal risks with twin pregnancies was low. The female need more support to accept and choose single embryo transfer, compared to the male and information should in some areas be directed differently to females and males.     

Non-persistent pesticides in breast milk in an agricultural area in Turkey

Background: Organophosphates, pythyreoids, carbamate pesticides and fungicides are heavily used in agriculture. They may have dangerous effects on newborn health especially on immune system and growth via prenatal transmission by placenta or postnatal transmission by breastfeeding.

Methods: In 2015, 144 non-persistent pesticides in 64 milk samples of 32 mothers were studied by OuEChERS method in liquid chromatography/tandem mass spectrometer in neonatal Intensive Care Unit in Adana, a city in Cukurova region which is an important agricultural area in Turkey.

Results: Pesticides were detected in milk samples of 11 mothers (34.3%) and 21 (32.8%) of milk samples. In five mothers, fungicides (in 5/10 samples propicanozole-PP, in 4/10 samples bromucanozole-BM), in five mothers, organophosphates (in 10/10 samples primyphosphomethyl-PPM), in one mother, both organophosphates and fungicide (in 1/2 samples PPM and in 1/2 samples buprimate) were detected. However, the estimated daily intakes (EDI) were less than acceptable daily intakes (ADI) for PPM, PP and BM, respectively.

Conclusions: Although pesticides levels in human milk did not exceed the ADIs, we suggest monitoring pesticides in human breast milk especially for newborn health.     

Ovulation induction in in vitro fertilization

The main goal of an in vitro fertilization (IVF) program is to maximize the number of women who become pregnant in any treatment cycle. In order to achieve pregnancy, many steps should be successfully accomplished. The number of mature oocytes that are retrieved and fertilized in a treatment cycle has the major impact on the success rate of the IVF program. The chances of achieving conception increases dramatically when the number of embryos replaced into the uterus increases^1-3. Hence, most IVF treatment programs currently use some combination of ovulation induction agents in order to stimulate and aspirate as many follicles as possible.     

Heterogeneity in alpha-thalassemia interactions in Malays, Chinese and Indians in Malaysia

AIM: Interactions between different determinants of alpha-thalassemia raises considerable problems, particularly during pregnancies where antenatal diagnosis is necessary. This study aims to determine the different types of deletional alpha-thalassemia and Hemoglobin Constant Spring (HbCS), and their frequency in Malays, Chinese and Indians in Malaysia. METHODS: DNA from 650 pregnant women from the Antenatal Clinic of the University of Malaya Medical Center in Kuala Lumpur, Malaysia who showed mean cell volume < or =89 fL and/or mean cell hemoglobin < or =28 pg were analyzed for the double alpha-globin gene South-East Asian deletion (--SEA), the -alpha3.7 and -alpha4.2 single alpha-globin gene deletions and HbCS. RESULTS: One hundred and three (15.8%) of the pregnant women were confirmed as alpha-thalassemia carriers: 25 (3.8%) were alpha-thalassemia-1 carriers with the --SEA/alphaalpha genotype, 64 (9.8%) were heterozygous for the -alpha3.7 rightward deletion (-alpha3.7/alphaalpha), four (0.6%) were heterozygous for the -alpha4.2 leftward deletion (-alpha4.2/alphaalpha), nine (1.4%) were heterozygous for HbCS (alphaCSalpha/alphaalpha) and one (0.2%) was compound heterozygous with the -alpha3.7/alphaCSalpha genotype. The double alpha-globin gene --SEA deletion was significantly higher in the Chinese (15%) compared to the Malays (2.5%) and not detected in the Indians studied. The -alpha3.7 deletion was distributed equally in the three races. HbCS and -alpha4.2 was observed only in the Malays. CONCLUSION: The data obtained gives a better understanding of the interactions of the different alpha-thalassemia determinants in the different ethnic groups, thus enabling more rapid and specific confirmation of alpha-thalassemia in affected pregnancies where antenatal diagnosis is necessary.     

缺氧缺血性脑病的性别差异性研究进展

新生儿缺氧缺血性脑病(hypoxic-ischemic encephalopathy,HIE)是指围产期窒息缺氧导致的脑缺氧缺血性损害,可遗留不同程度的神经系统后遗症。动物研究表明,缺氧缺血性损伤后,炎性反应、氧化应激和细胞死亡途径等关键病理生理过程中存在明显的性别差异,雌性动物对亚低温、促红细胞生成素、脑源性营养因子和别嘌呤醇等治疗效果也明显优于雄性。临床研究发现男性HIE患儿病情更重、预后更差。基于性别的治疗干预很有可能在围产期脑损伤中提供更好的神经保护。本文总结了目前HIE性别差异性的相关证据,以期为临床治疗提供新思路。     

Trends in preterm birth in singleton deliveries in a Hong Kong population

Objective

To examine trends in preterm birth and its relationship with perinatal mortality in Hong Kong.

Methods

In a retrospective cohort study, data were reviewed from singletons delivered between 1995 and 2011 at a university teaching hospital. Trends in preterm birth (between 24 and 36 weeks of pregnancy), perinatal mortality, and subtypes of preterm birth (spontaneous, iatrogenic, and following preterm premature rupture of membranes [PPROM]) were examined via linear regression.

Results

There were 103 364 singleton deliveries, of which 6722 (6.5%) occurred preterm, including 1835 (1.8%) early preterm births (24–33 weeks) and 4887 (4.7%) late preterm births (34–36 weeks). Frequency of preterm birth remained fairly consistent over the study period, but that of spontaneous preterm birth decreased by 25% (β = –0.83; P < 0.001), from 4.5% to 3.8%. Frequency of preterm birth following PPROM increased by 135% (β = 0.82; P < 0.001), from 0.7% to 1.7%. The perinatal mortality rate decreased from 56.7 to 37.0 deaths per 1000 deliveries before 37 weeks (β = –0.16; P = 0.54). Early preterm birth contributed to 16.0% of all deaths.

Conclusion

Although the overall rate of preterm birth in Hong Kong has remained constant, the frequencies of its subtypes have changed. Overall perinatal mortality is gradually decreasing, but early preterm birth remains a major contributor.