早发型重度子痫前期及保守治疗对早产儿预后影响因素分析

目的 探讨早发型重度子痫前期以及保守治疗对早产儿预后的影响.方法 对2001年1月至2006年5月于北京大学第三医院产科分娩、孕周<34周的早发型重度子痫前期患者76例(研究组)活产早产儿及同期孕周匹配的自发性早产患者84例(对照组)活产儿进行生长发育评估.研究组活产早产儿86例,随访71例(82.6%);对照组活产新生儿114例,随访96例(84.2%).应用丹佛智能发育筛查表(DDST)进行智能发育筛查.观察指标包括:DDST测评结果,妊娠期及围生期病历资料和临床指标.结果 研究组早产儿存活56例,存活儿智能发育正常43例(77%),可疑12例(21%),无法解释1例(2%),未发现智能发育异常或脑瘫患儿.对照组早产儿存活86例,存活儿智能发育正常65例(76%),可疑14例(16%),异常5例(6%,均为脑瘫患儿),无法解释2例(2%).早发型重度子痫前期早产儿与自发性早产早产儿比较智能发育差异无统计学意义(P>0.05).多因素分析显示,胎龄和新生儿窒息是影响早发型重度子痫前期婴儿期生存率的主要因素;出生体重是影响智能发育的保护性因素(OR0.278,95% CI 0.087～0.891).结论 在早期早产中,重度子痫前期影响小儿存活率,但不是影响小儿智能发育的因素;出生体重是早产儿智能发育的保护性因素.早发型重度子痫前期行长时间保守治疗对智能发育无不良影响;经严格选择病例,进行保守治疗延迟分娩,可以最大程度改善胎儿成熟度,改善预后.     

早发型重度子痫前期期待治疗妊娠结局的多因素分析

目的探讨早发型重度子痫前期期待治疗中母儿不良妊娠结局的独立危险因素。方法对57例经期待治疗的早发型重度子痫前期孕妇的临床资料进行总结分析,按照有无孕妇及新生儿严重并发症（包括新生儿死亡）的发生分别分为孕妇不良妊娠结局组与对照组和新生儿不良结局组与对照组,分别比较两组患者的一般临床情况及各项检验指标。采用多因素Logistic回归分析母儿不良妊娠结局的危险因素。结果57例早发型重度子痫前期期待治疗中,16例孕妇出现严重并发症,发生率为16/57（28.1%）,无孕产妇死亡。胎死宫内3例,12例新生儿出现明显并发症,其中6例新生儿死亡,围产儿死亡率为9/57（15.8‰）。经多因素回归分析,发病孕周（以30周为界）及血小板减少是孕妇严重并发症发生的独立危险因素,比数比分别为5.2（95%CI 1.1-24.0,P=0.04）和4.6（95%CI 1.2-17.6,P=0.03）。分娩孕周（以32周为界）是新生儿病率及死亡率的独立危险因素,比数比为6.0（95%CI 1.5-24.9,P=0.01）。结论早发型重度子痫前期期待治疗中需严密监护。发病孕周不足30周及血小板降低者孕妇严重并发症的发生显著增加,而分娩孕周超过32周,新生儿结局将显著改善,因此需权衡利弊,选择恰当时机终止妊娠。     

67例早发型重度子痫前期患者围产儿预后分析

目的目的探讨67例早发型重度子痫前期患者围产儿预后及相关影响因素。方法回顾性分析2003年12月-2010年3月在北京友谊医院妇产科妊娠28～33＋6周分娩的67例早发型重度子痫前期患者的临床资料,探讨围产儿预后及相关影响因素。结果 71例（双胎4例）围产儿中胎死宫内13例,治疗性引产过程中死产5例,新生儿重度窒息死亡8例,1例出生后4d因ARDS死亡,围产儿总死亡率380‰（27/71）;新生儿出生缺陷发生率70%（5/71）。45例存活的新生儿中失访11例,34例新生儿随访1个月～6年,1例产后10d死亡,1例产后1＋个月发现脑瘫,31例新生儿后期发育未见明显异常。影响围产儿死亡的相关因素：新生儿出生体重（P=0.000）、分娩孕周（P=0.001）、规律产检（P=0.03）、期待治疗的天数（P=0.04）;与胎死宫内明显相关的因素为胎盘早剥（P=0.037）、严重FGR（P=0.001）。与围产儿死亡不相关的因素：孕妇年龄、产次、体重指数、平均动脉压、24h尿蛋白。结论早发型重度子痫前期孕妇围产儿死亡率较高,母体严重并发症和孕周是影响围产儿死亡的主要因素,加强围产期保健、积极防治并发症、适时终止妊娠可改善围产儿预后。     

孕母子(癎)前期、子(癎)对新生儿脑损伤及神经发育的影响

目的 研究孕母妊娠期合并子痫前期、子痫对新生儿脑损伤及远期神经发育的影响。方法 通过临床观察和动态颅脑影像学检查，观察子痫前期、子痫母亲所生265例新生儿脑损伤的情况，并对神经系统发育情况进行随访。结果 新生儿脑损伤发生率为63．0％。损伤类型主要是脑室旁白质损伤和缺氧缺血性脑病。母亲子痫前期、子痫的病情越重新生儿重度脑损伤的发生率越高，早发型重度子痫前期孕母的新生儿重度脑损伤的发生率（38．5％）明显高于晚发型（19．4％）（P〈0．05）。214例随访患儿中有56．1％出现了神经发育异常：严重神经发育异常发生率为3．3％；轻度神经发育异常发生率为17．3％；一过性神经发育异常发生率为35．5％。母亲子痫前期、子痫的病情越重小儿神经发育异常的发生率越高，重度脑损伤小儿神经发育异常的发生率（93．5％）明显高于轻度脑损伤者（66．7％）（χ^2=82．5，P〈0．01）。小儿神经发育异常的危险因素是孕母重度子痂前期（OR=4．37，95％CI1．67～8．35）和新生儿期重度脑损伤（OR=9．66，95％CI3．73～21．16）。结论 母亲子痫前期、子痫程度越重，其新生儿脑损伤和生长过程中神经发育异常发生率越高，早发型重度子痫前期孕母的新生儿重度脑损伤的发生率高于晚发型，重度子痫前期和重度脑损伤是小儿神经发育异常的危险因素。因此，对于子痫和子痫前期孕母所生新生儿要加强监测，早诊断、早干预以改善预后。     

早发型重度子痫前期期待治疗及妊娠结局

目的：探讨早发型重度子痫前期期待治疗和终止妊娠时机选择对母儿结局的影响。方法：对72例早发型重度子痫前期病例进行回顾性分析,按终止妊娠的孕周分3组,比较母儿结局。结果：随期待治疗时间的延长,新生儿窒息率和死亡率明显下降（P〈0．01）,而孕妇并发症无明显增加。结论：对早发型重度子痫前期,期待治疗和适时终止妊娠是最大限度降低孕产妇和围产儿死亡率的重要方法。     

重度子(癎)前期早产与自发性早产临床对比分析

目的:通过不同类型的重度子前期(severe preeclampsia,S-PE)早产和自发早产的对比分析,探讨影响S-PE早产结局的相关因素。方法:将重度子前期(研究组)早产72例(早产儿83例),按不同孕周分为早期早产、中型早产及轻型早产3类,分别与相同类型的自发早产(对照组)222例(早产儿279例)进行孕产妇及围生儿结局对比分析。结果:研究组及对照组3类型间的早产儿病死率差异有显著性(P=0.000)。研究组与对照组同类型间早产儿病死率比较,差异无显著性(P>0.05);研究组早期早产儿平均出生体重明显低于对照组(P=0.003),而早产儿并发症发生率与对照组比较,差异无显著性(P>0.05);研究组中的中型早产新生儿除重度窒息明显高于对照组外(P=0.022),新生儿平均出生体重、新生儿轻度窒息率、新生儿病死率及新生儿加强护理NICU(neonatel intensive care unit,NICU)住院日和住院费两组间差异无显著性;在轻型早产组,除研究组NICU住院日明显长于对照组外(P=0.000),两组间其他观察指标的差异均无显著性。多元回归分析显示,早产的分娩孕龄是影响重度子前期早产儿死亡的主要因素;促胎肺成熟和孕期检查是影响新生儿病率的主要因素。结论:不论重度子前期早产还是自发早产,在早期早产阶段影响围生儿预后的主要因素是分娩孕龄,重度子前期早产与自发早产围生结局无明显差异。     

早发型重度子痫前期的临床特点及围生期结局

目的探讨早发型重度子痫前期患者的临床特点及对母婴预后的影响。方法选取2001年1月～2004年12月天津市中心妇产科医院住院的794例重度子痫前期患者作为研究对象，将病例分为早发型重度子痫前期（妊娠〈32周，312例）和晚发型重度子痫前期（妊娠≥32周，482例）。回顾性分析比较两组患者的临床资料。结果早发型重度子痫前期组临床严重并发症如子痫、心衰、肺水肿、腹水、胸腔积液、胎盘早剥、产后出血的发生率均明显高于晚发型重度子痫前期组，差异有显著性（P〈0．01）；早发型重度子痫前期组围产儿死亡率及新生儿Apgar评分≤7分的发生率显著高于晚发型重度子痫前期组（P〈0．01）。结论早发型重度子痫前期病情严重，围产儿预后不良，应根据母婴情况，严格选择病例进行期待疗法，同时密切监测母婴病情变化。     

早发型重度子痫前期期待治疗探讨

妊娠期高血压疾病是妊娠期常见的特发性疾病,重度子痫前期是孕产妇及围产儿死亡的重要原因。有学者将在32孕周前发病的重度子痫前期称为早发型,然而更多的学者将于34孕周前发病的重度子痫前期称为早发型[1]。早发型重度子痫前期临床上处理非常棘手。现对我院1997年8月至2006年10月收治的早发型重度子痫前期患者的临床资料作一回顾分析,重点探讨不同孕周的早发型重度子痫前期期待治疗对母儿结局的影响。1资料与方法1.1一般资料1997年8月至2006年10月在我院妇产科分娩总共18 829例,其中重度子痫前期175例,发病率0.93%。诊断标准参照高等院校统…     

早发型重度子痫前期对母婴预后的影响

目的:探讨早发型重度子痫前期对妊娠结局的影响.方法:回顾性分析我院收治的218例重度子痫前期患者(其中早发型组72例,晚发型组146例,围生儿235例)的母婴结局.结果:①早发型重度子痫前期患者收缩压为168.4±20.5 mmHg,舒张压为106.8±16.5 mmHg,高于晚发组159.4±15.9 mmHg和101.5±11.2 mmHg(P均＜0.05);早发型组治疗时间为4.0±3.7天,长于晚发型组(1.3±2.4)天(P＜0.01);早发型组分娩孕周为33.6±2.6周,早于晚发型组38.4±1.8周(P＜0.01);②早发型组母亲低蛋白血症的发生率55.6%,高于晚发型组34.3%(P＜0.01);早发型组母亲心功能不全、子痫、HELLP综合征、胎盘早剥、视网膜剥离、肾功能损害等严重并发症总发生率为26.4%,高于晚发型组14.3%(p＜0.05);③早发型纽围生儿体重低于晚发型组(P＜0.01),且早发型组围生儿中早产、FGR、新生儿窒息、转入NICU及围生儿死亡率均分别高于晚发型组(P均＜0.01);④早发型组中发病孕周越早,围生儿体重越低(P＜0.01),入住NICU率越高(P＜0.01),围生儿死亡率、FGR及早产发生率逐渐增加.结论:早发型重度子痫前期孕妇病情严重,围生儿预后不佳,且发病越早,围生儿预后越差.严格选择病例行短期的期待治疗是安全有效的.     

早发型和晚发型重度子痫前期分娩方式及母婴结局分析

目的探讨早发型和晚发型重度子痫前期分娩方式及母婴结局。方法收集1977-2010年在西安交通大学医学院第一附属医院产科住院的重度子痫前期患者4457例,其中早发型860例,晚发型3597例。回顾性分析其分娩方式及母婴结局。结果早发型和晚发型重度子痫前期剖宫产率分别为57.7%和36.9%,早发型明显高于晚发型(P=0.02);胎盘早剥是最常见并发症,在早发型和晚发型重度子痫前期发生率分别为6.7%和4.6%(P<0.05)。早发型和晚发型重度子痫前期围生儿死亡率分别为3.6%和2.2%(P<0.01)。特别是早发型妊娠34周前终止妊娠者,围生儿死亡率高达4.9%。结论子痫前期终止妊娠的主要方式为剖宫产术;发病孕周越早,母婴不良结局发生率越高。     

Pregnancy-induced hypertension is associated with lower infant mortality in preterm singletons

OBJECTIVE: To assess the association between pregnancy-induced hypertension (PIH) and infant mortality. DESIGN: Retrospective cohort study. SETTING: Birth and infant death registration dataset of the USA. POPULATION: A total of 17,432,987 eligible, liveborn singleton births in 1995-2000. METHODS: Multivariate logistic regression was applied to evaluate the association between PIH and infant mortality, with adjustment of potential confounders. MAIN OUTCOME MEASURES: Infant death (0-364 days) and its three components: early neonatal death (0-6 days), late neonatal death (7-27 days), and postneonatal death (28-364 days). RESULTS: There was a significant reduction in infant mortality associated with PIH in early preterm infants (OR = 0.59, 95% CI: 0.56-0.63) and in late preterm infants (OR = 0.80, 95% CI: 0.73-0.87), but a significant increase in term infants (OR = 1.08, 95% CI: 1.02-1.14). Both in early preterm and late preterm births, early neonatal mortality (OR = 0.38, 95% CI: 0.34-0.42; OR = 0.68, 95% CI: 0.61-0.77) and late neonatal mortality (OR = 0.59, 95% CI: 0.50-0.70; OR = 0.76, 95% CI: 0.61-0.96) were decreased in infants born to mothers with PIH compared with those born to mothers with normal blood pressure. The PIH-associated reduction in neonatal mortality among preterm singletons was stronger in small-for-gestational-age infants than in normal growth infants and stronger in infants born to nulliparous women than in those born to multiparous women. CONCLUSIONS: PIH is associated with lower risk of infant death in preterm births but higher risk in term births.     

Neonatal outcome of temporizing treatment in early-onset preeclampsia

OBJECTIVE: To assess the effect of prolongation of pregnancy on neonatal outcome by means of hemodynamic treatment in patients with early-onset preeclampsia. STUDY DESIGN: A retrospective case-controlled study of 222 liveborn infants of patients with early-onset (24--31 weeks) preeclampsia, who underwent temporizing hemodynamic treatment. Of the two control groups of liveborn preterm infants of non-preeclamptic mothers one group was matched with the study group for gestational age on admission (group I), one for gestational age at birth (group II). Primary outcome measures were neonatal and infant mortality and variables of neonatal morbidity. RESULTS: Median gestation in the study group of preeclamptic patients was prolonged from 29.3 to 31.3 weeks. No difference in neonatal or infant mortality was observed between infants from preeclamptic mothers and in the control groups. The study population showed better results than control group I with regard to admission to NICU (P<0.01), mechanical ventilation (P<0.001) and intracranial hemorrhage (P<0.01). Control group II had better results than the study group with respect to birthweight (P<0.001), bronchopulmonary dysplasia (P<0.01), patent ductus arteriosus (P<0.01), and retinopathy (P<0.01). CONCLUSION: Prolongation of gestation in patients with early-onset preeclampsia may reduce neonatal morbidity, but neonates of the same gestational age without a preeclamptic mother still have a better prognosis.     

早产相关因素及早产儿结局临床分析

目的探讨早产发生的高危因素及早产对围生儿的影响。方法选取2001年1月1日-2007年6月30日在我院分娩的早产儿508例作为病例组，并随机选取同期足月分娩产妇508例作为对照组，比较两组产妇的相关情况，围产儿结局，分析早产的高危因素。结果早产儿窒息、RDS发生率及死亡率与足月儿相比差异显著；孕周越小，发病率及死亡率越高。胎膜早破、胎位异常、胎盘因素是造成早产的高危因素。应用地塞米松与未应用者相比，足量应用地塞米松与未足量应用者相比，新生儿并发症发生率、早产儿死亡率均明显降低。孕35周后早产患者，延长孕周并不能降低早产儿并发症发生率及死亡率。结论早产的发生是多种因素的结果。孕周越小，早产儿发病率及死亡率越高。应用糖皮质激素是改善早产儿结局的重要治疗措施。35～36^＋6周PPROM者建议在破膜48h内分娩，以减少早产儿并发症。     

早期 晚期早产儿与足月新生儿 呼吸窘迫综合征临床比较分析

目的　 探讨早期、晚期早产儿与足月儿呼吸窘迫综合征（RDS）的发病趋势和临床特征的差异,为临床合理诊治提供依据。方法　2006年1月至2010年12月在郑州大学第三附属医院住院的963例RDS患儿根据胎龄不同分为早期早产儿组（ < 34周）679例,晚期早产儿组（34～ < 37周）204例,足月儿组（≥37周）80例,分别对各组患儿的发病率、入院情况、高危因素、临床诊治、预后及并发症进行比较。结果　RDS的发病率逐年增加,均以早期早产儿占多数,晚期早产儿和足月儿RDS比例有增多趋势;RDS患儿男婴超过女婴（P < 0.05）,且胎龄和体重越大,男婴比例越高;足月儿RDS组产前糖皮质激素使用率明显低于早产儿组;早产儿发生RDS的高危因素主要有胎膜早破、胎盘异常、母亲妊娠高血压疾病,足月儿发生RDS的高危因素主要是择期剖宫产与感染;晚期早产儿与足月儿RDS的临床诊断和应用肺泡表面活性物质（PS）时间均晚于早期早产儿;足月儿RDS应用机械通气比例明显高于早产儿,其临床治愈率高（P < 0.05）,在死亡率方面与早产儿组无差别;但并发气胸的比例高于早产儿组（P < 0.05）。结论　新生儿呼吸窘迫综合征（NRDS）发病率逐年增高,晚期早产儿和足月儿RDS比例有增多趋势;早期、晚期早产儿与足月儿RDS在性别比例、高危因素、起病特点、治疗反应与并发症方面均存在差异,RDS的诊治需要考虑胎龄因素。足月儿RDS多与择期剖宫产、感染有关,发病相对较晚,容易合并气胸,应引起足够重视。     

Perinatal outcome of singleton versus twin late preterm infants: do twins mature faster than singletons?

Objective: To determine whether as a result of an assumed advanced maturation late preterm twin infants have a more favorable perinatal outcome than singleton late preterm infants.

Methods: Over a 36-month period (from September 2011 to September 2014), 277 late preterm infants (153 from singleton and 124 from twin pregnancies) were hospitalised in NICU, University Hospital Center “Sisters of Mercy” Zagreb, Croatia, and were retrospectively studied by review of maternal and neonatal charts for gestational age, sex, birth weight, mode of delivery, 5-min Apgar score and for several outcome variables expected for preterm infants, until the day of discharge.

Results: There was statistically no significant difference in the incidence of any of the observed and compared outcomes, except in the incidence of phototherapy which was higher in singletons group (49.01 versus 13.7%, p?<?0.0001). The mean birth weight, as expected, was smaller in the twin group. Conclusions: We found no evidence to support the traditional belief that twin late preterm infants have accelerated maturation and better neonatal outcome compared with singleton late preterm infants. Our findings suggest that late preterm twins have a prognosis similar to that of singleton late preterm infants born at the same gestational age.     

Evaluation of a definition of pre-eclampsia.

OBJECTIVES: To determine: 1. whether an alternative definition of gestational hypertension and pre-eclampsia stratifies women according to their risk of maternal and fetal complications; 2. whether pregnancy outcome in women with gestational hypertension differs in the presence or absence of '+' proteinuria; and 3. whether a blood pressure rise of > or = 30/15 mmHg during pregnancy is associated with adverse outcome in women who remain normotensive. DESIGN: Prospective, nested case-control study. SETTING: Community based. POPULATION: Healthy, nulliparous women (n = 1496). METHODS: Women recruited into a study investigating serum markers predictive of pre-eclampsia were classified as having gestational hypertension (systolic blood pressure > or = 140 mmHg with a rise of > or = 30 mmHg and/or diastolic blood pressure > or = 90 mmHg with a rise of > or = 15 mmHg) or pre-eclampsia (gestational hypertension plus proteinuria > or = 2+on dipstick or > 0.3 g/24 h). Maternal and fetal complications in gestational hypertension or pre-eclampsia were compared with a control group of 223 randomly selected normotensive women. The main outcome measures were severe maternal disease, preterm birth and small for gestational age infant. RESULTS: A stepwise increase in adverse maternal and fetal outcomes occurred in gestational hypertension (n = 117, 7.8%) and pre-eclampsia (n = 71, 4.8%). Severe maternal disease developed in 26.5% (21.4% severe hypertension alone, 5.1% multisystem disease) of women with gestational hypertension and 63.4% (21.1% severe hypertension alone, 42.3% multisystem disease) of women with pre-eclampsia (OR 4.8; 95% CI 2.4-9.5). Preterm birth and small for gestational age infants were more frequent in gestational hypertension (OR 1.7; 95% CI 0.5-5.4, and OR 2.0; 95% CI 1.0-3.7, respectively) and pre-eclampsia (OR 14.6; 95% CI 5.8-37.8, and OR 2.6; 95% CI 1.2-5.3) than in the normotensive group. Among women with gestational hypertension severe maternal disease was more common in women with '+' proteinuria (41.7%) than in those with no proteinuria (15.9%): OR 3.8; 95% CI 1.5-9.8. Pregnancies were uncomplicated in the 27% of normotensive women who had a rise of > or = 30 mmHg systolic blood pressure and/or > or = 15 mmHg rise in diastolic blood pressure. CONCLUSIONS: In the nulliparous population studied our definition of gestational hypertension and pre-eclampsia identified women at increasing risk of maternal and fetal complications. In gestational hypertension, the presence of proteinuria '+' was associated with a 3.8-fold increase in severe maternal disease. Normotensive women who have a rise in blood pressure > or = 30/15 mmHg had uncomplicated pregnancies.     

Preterm delivery for maternal or fetal indications: maternal morbidity, neonatal outcome and late sequelae in infants

Objective To assess maternal morbidity, and neonatal outcome and especially long term sequelae in infants born preterm due to maternal or fetal indications.
Design Analysis of retrospective cohort.
Setting Oulu University Central Hospital, Finland.
Population One hundred and three women, who were between the 24th and the 33rd week of pregnancy, delivered by caesarean delivery because of maternal or fetal indications. They were matched with 103 women who had spontaneous preterm delivery at corresponding gestational weeks between 1990–1997.
Main outcome measures Maternal morbidity, reasons for caesarean delivery, neonatal mortality and morbidity rates, and later development of the infants.
Results Pre-eclampsia was diagnosed in 57% of the women in the indicated group and only in one woman in the control group. All infants in the indicated group and almost a third in the control group were born by caesarean birth; the main indication was threatening fetal asphyxia. There was a significant difference in neonatal mortality rates between the groups (175 vs 78 per thousand live births in the indicated vs control infants; RR 2.3, 95% CI 1.02, 4.9) and the main cause of death was respiratory insufficiency: 64% in the indicated group and 22% in the controls; RR 2.9, 95% CI 0.8, 10. Respiratory distress syndrome occurred more often (73% vs 53%, RR 1.4, 95% CI 1.1, 1.7) and it was more severe and more complicated in infants in the indicated group, compared with those in the control group. Symptomatic chronic lung disease at one year of age was more common in infants in the indicated group than in the control group (15% vs 3%; RR 4.6, 95% CI 1.4, 15.9).
Conclusions Not only the risks of neonatal mortality and morbidity but also long term pulmonary consequences, appear to be greater in infants born preterm by indicated delivery than in preterm infants born spontaneously at corresponding weeks.     

Pregnancy-induced hypertension and infant mortality: Roles of birthweight centiles and gestational age

OBJECTIVE: To assess the effect of pregnancy-induced hypertension (PIH) on infant mortality in different birthweight centiles (small for gestational age [SGA], appropriate for gestational age [AGA], and large for gestational age [LGA]) and gestational ages (early preterm, late preterm, and full term). DESIGN: Retrospective cohort study. SETTING: Linked birth and infant death data set of USA between 1995 and 2000. POPULATION: A total of 17 464 560 eligible liveborn singleton births delivered after 20th gestational week. METHODS: Multivariate logistic regression models were applied to evaluate the association between PIH and infant mortality, with adjustment of potential confounders stratified by birthweight centiles and gestational age. MAIN OUTCOME MEASURE: Infant death (0-364 days) and its three components: early neonatal death (0-6 days), late neonatal death (7-27 days), and postneonatal death (28-364 days). RESULTS: PIH was associated with decreased risks of infant mortality, early neonatal mortality, and late neonatal mortality in both preterm and term SGA births, and PIH was associated with lower postneonatal mortality in preterm SGA births. PIH was associated with decreased risks of infant mortality, early neonatal mortality, late neonatal mortality and postneonatal mortality in preterm AGA births. Decreased risk of infant mortality and early neonatal mortality was associated with PIH in early preterm LGA births. CONCLUSIONS: The association between PIH and infant mortality varies depending on different birthweight centiles, gestational age, and age at death. PIH is associated with a decreased risk of infant mortality in SGA births, preterm AGA births, and early preterm LGA births.