孕妇血清P、HPL与先兆早产相关性研究

目的观察孕妇妊娠晚期血清P、HPL对早产的预测价值。方法将受试者分成两大组,研究组(先兆早产)、对照组(正常孕妇),先兆早产组经过保胎治疗后继续妊娠或者发生难免早产的患者,对这两组孕妇根据不同的孕周分别再分成三组,分别检测其血清中P,HPL的值,分别计算其平均水平,每两组相同孕周的孕妇进行比较。结果孕妇血清中P、HPL随孕周增加其值也在相应的上升,但研究组早产组中的患者明显低于对照组患者。结论检测孕妇妊娠晚期血清中P、HPL值可以预测早产。     

血清C反应蛋白对妊娠糖尿病的预测价值

目的探讨妊娠妇女血清c反应蛋白（CRP）预测妊娠糖尿病（GDM）的价值。方法对484名早孕妇女进行前瞻性研究,用免疫散射比浊法检测早孕妇女血清CRP并追踪至孕中晚期,根据孕中晚期75g糖耐量结果分为GDM组、IGT组,选取年龄、孕周相同的作为正常对照组,对3组间孕早期、孕中晚期的CRP进行分析。结果GDM的发生率为4．5％、IGT的发生率为5．12％。孕早期3组间血清CRP水平差异无统计学意义;孕中晚期GDM组、IGT组血清CRP浓度明显高于正常对照组,差异有显著性;孕前BMI与CRP存在正相关性。当校正孕前BMI进行协方差分析后,GDM组、IGT组血清CRP与正常组血清CRP差异有统计学意义,GDM组、IGT组差异无显著意义。结论妊娠早期血清CRP水平不能预测GDM的发生,孕中晚期血清CRP水平高低对GDM有诊断价值。     

正常孕妇不同孕周血清中sHLA-G的水平

目的: 探讨正常妊娠妇女不同孕周血清可溶性人类白细胞抗原G(sHLA-G)在妊娠过程中的作用.方法: 采用ELISA法检测20例正常孕妇不同孕周血清中的sHLA-G水平.结果: 血清sHLA-G的水平在正常妊娠的早、中、晚孕期的均值依次为(11.96±4.27)ìg/L、 (11.50±4.17)ìg/L、 (10.72±3.40)ìg/L; 差异无统计学意义.结论: 血清sHLA-G的水平在正常妊娠的整个过程中差别不大, 对维持胎儿的正常发育具有重要意义.     

胎儿纤维连接蛋白联合超声宫颈管长度检测对预测早产意义

目的探讨B超宫颈管长度测量联合宫颈分泌物胎儿纤维连接蛋白(FFN)含量检测对准确预测早产的意义。方法选择61例已出现宫缩的未足月单胎妊娠孕妇,年龄23~38岁,平均年龄31.61岁;孕周28~34周,平均孕周31.25周。根据妊娠结局分为早产组与足月组。足月组29例,年龄23~37岁,平均年龄30.15岁;孕周37~42周,平均孕周40.11周。早产组32例,年龄24~38岁,平均年龄31.93岁;孕周29~36周,平均孕周33.67周。对比两组宫颈管长度及宫颈分泌物FFN含量,分析宫颈分泌物FFN含量、宫颈管长度与早产的相关性,对比B超宫颈管长度测量联合宫颈分泌物检测与单项检测诊断早产的灵敏度、特异度及准确度。结果早产组宫颈分泌物FFN含量较足月组高[(136.25±24.63)ng/L vs(51.36±10.32)ng/L;t=17.230,P0.05)],宫颈管长度较足月组短,差异有统计学意义[(21.03±5.11)mm vs(40.17±7.04)mm;t=12.233;P0.05]。宫颈分泌物FFN含量与早产呈正相关,宫颈管长度与早产呈负相关(r=0.249、-0.414;P0.05);宫颈分泌物FFN含量诊断早产的灵敏度为75.00%、特异度为89.66%、准确度为81.97%,宫颈管长度诊断早产灵敏度为71.88%、特异度为96.55%、准确度为83.61%;FFN含量联合宫颈管长度诊断早产灵敏度为96.88%、准确度为98.36%,均高于FFN含量、宫颈管长度单独诊断,差异有统计学意义(P0.05);联合诊断特异度(100.0%)与各项单独检测比较,差异无统计学意义(P0.05)。结论超声宫颈管长度测量联合宫颈分泌物FFN含量检测,可提高早产预测准确率,减少漏诊、误诊等情况发生,有利于帮助临床制定正确干预方案。     

血清血管内皮生长因子、妊娠相关血浆蛋白A在异位妊娠中的研究

目的探讨血清血管内皮生长因子(vascular endothelia l growth factor,VEGF)及妊娠相关血浆蛋白A(preg-nancy-associated plasma protein-A,PAPP-A)在异位妊娠患者血清中的改变及其意义。方法收集57例正常早孕孕妇血清(孕龄为5-8周),92例异位妊娠患者血清,采用酶联免疫吸附技术(ELISA),分别检测血清VEGF及PAPP-A水平。结果与正常妊娠组比较,同孕龄异位妊娠患者VEGF水平均明显升高,差别具有显著意义(P<0.05);PAPP-A与同孕龄正常宫内孕比较,在孕龄<7周时差异不明显(P>0.05),≥7周时明显降低,差别具有显著意义(P<0.05)。结论在异位妊娠的早期诊断中,血清VEGF和PAPP-A相比,VEGF是更为敏感的指标。     

孕中期唐氏筛查假阳性在预测胎膜早破中的临床意义

目的探讨孕中期唐氏筛查假阳性在预测胎膜早破中的临床意义。方法我院2009年1月至2013年7月有321例妊娠中期唐氏筛查高风险孕妇,均行染色体检查排除染色体异常,孕期序列超声检查未见胎儿器官结构异常,电话或者门诊随访妊娠结局;同时随访346例低风险孕妇妊娠结局,孕期超声亦未发现器官结构异常。结果 321例孕妇唐氏筛查假阳性孕妇中,14例因胎膜早破流产(孕龄小于28周);17例因胎膜早破早产,其中孕28周至孕34周为9例,孕34周至孕37周为8例;新生儿窒息为7例。低风险组中,孕28周前因胎膜早破发生流产6例,3例孕28周至孕34周之间因胎膜早破发生流产,4例孕34周至孕37周发生胎膜早破,新生儿窒息为3例。结论唐氏筛查假阳性孕妇相对于低风险孕妇,更容易发生胎膜早破;唐氏筛查高风险可作为预测胎膜早破的一个潜在指标。     

妊娠妇女肝内胆汁淤积症血清CG测定的意义

妊娠性肝内胆汁淤积症(ICP)是妊娠妇女常见的并发症, 表现为皮肤瘙痒和轻度黄疸, 病因尚不明确, 但严重影响胎儿健康.目前实验室甘胆酸(CG)的检测是诊断及治疗监测ICP的重要指标.有报道在孕20周妇女血中即可出现CG含量增高, 但ICP多出现在孕28周以后.ICP患者预后良好, 但胎儿可发生早产、胎儿窘迫或胎死宫内等并发症.本文对80例ICP患者血清CG进行了测定, 现报道如下.     

解整合素-金属蛋白酶12与自然流产的相关性研究

目的探讨解整合素-金属蛋白酶12与自然流产的相关性。方法利用时间分辨检测技术,对1160例孕妇血清中ADAM12进行了检测,其中正常妊娠组1064例,自然流产96例。结果正常妊娠组血清中ADAM12含量随孕龄的进展稳定增加,自然流产组ADAM12含量明显低于同孕周正常妊娠组,差异有统计学意义(P0.05)。结论孕妇ADAM12的检测在预测自然流产方面有较高的准确性,在异常妊娠检测方面有较大的临床价值。     

胎儿出生缺陷与妇女血清叶酸水平、Hcy水平的相关性研究

目的探讨胎儿出生缺陷与妇女血清叶酸水平、Hcy水平的相关性。方法选取2018年6月-2019年6月住院分娩及产前检查没有合并不良妊娠32例孕妇为A组,同期住院合并不良妊娠32例孕妇为B组,健康体检34例育龄女性为C组。分析三组叶酸、Hcy水平、叶酸与血清Hcy水平相关性。结果 A组与C组Hcy水平没有明显区别(P0.05),三组叶酸、Hcy水平存在明显区别,A组叶酸水平低于C组,B组叶酸水平低于C组和A组(P0.05);正常非孕组及正常妊娠组叶酸、Hcy水平异常率低于不良妊娠组(P0.05)。正常非孕组没有胎儿异常出现,只有实验室辅助检查出现叶酸、Hcy异常;年龄及Hcy水平上升,FA水平下降为不良妊娠的独立危险因素(P0.05);叶酸补充前,两组Hcy水平存在明显区别(P0.05),叶酸补充后,两组Hcy水平没有明显区别(P0.05)。结论孕晚期及孕中期,Hcy水平明显升高,胎儿出生缺陷发生率上升。血清叶酸水平、Hcy水平早期检测,可对不良妊娠高危人群及时发现,为敏感度较高预测指标,可根据血清叶酸水平、Hcy水平检测结果,对叶酸及时补充,降低胎儿出生缺陷和妊娠并发症发生,改善妊娠结局,对预后改善具有非常重要作用,血清叶酸及Hcy水平检测值得在临床上进一步推广和应用。     

ADAM12与PAPP-A联合检测与自然流产相关性研究

目的探讨解整合素-金属蛋白酶12(ADAM12)和妊娠相关血浆蛋白A(PAPP-A)联合检测与自然流产的相关性。方法利用时间分辨检测技术,对2756例孕妇血清中ADAM12和PAPP-A进行了检测,其中正常妊娠组2660例,自然流产96例。结果正常妊娠组血清中ADAM12和PAPP-A含量随孕龄的进展稳定增加,自然流产组ADAM12和PAPP-A含量明显低于同孕周正常妊娠组,差异有统计学意义(P0.01)。结论孕妇ADAM12和PAPP-A联合检测在预测自然流产方面有较高的准确性,在异常妊娠检测方面有较大的临床价值。     

Bacterial vaginosis and preterm birth: a prospective community-based cohort study.

BACKGROUND: Preterm birth before 37 weeks' gestation is associated with 70% of perinatal morbidity and nearly half of long-term neurological morbidity. Hospital-based studies have shown that bacterial vaginosis is associated with preterm birth. AIM: To estimate the relative risk of preterm birth in women with and without bacterial vaginosis, detected by self-administered vaginal swab at < 10 weeks' gestation. DESIGN: Prospective cohort study. SETTING: Thirty-two general practices and five family planning clinics in South London. PARTICIPANTS: A total of 1216 women with bacterial vaginosis status established before 10 weeks' gestation, by analysis of Gram stained vaginal smears by two independent observers. METHOD: All women who did not miscarry or have a termination of pregnancy before 16 weeks' gestation were sent a brief confidential questionnaire at 16 weeks and at term asking about pregnancy outcome. Data on non-responders were obtained by searches of hospital and general practice records and by telephone calls to patients. RESULTS: Ascertainment was 87% (937/1072). The mean age of the women was 31 years. Thirteen per cent (122/925) had bacterial vaginosis and 5% (44/897) had a spontaneous preterm birth. The relative risk (RR) of preterm birth in women with bacterial vaginosis was 0.9 (95% confidence interval [CI] = 0.4 to 2.2). However, bacterial vaginosis was associated with late miscarriage at 13-23 weeks (R = 4.0, 95%CI = 1.3 to 12.1). Preterm birth was not associated with previous preterm birth, black ethnicity, age < 20 years, low social class, single marital status, or chlamydial infection. However, it was more common in women who reported smoking in pregnancy (RR = 2.9, 95% CI = 1.5 to 5.5). Of 867 responders, 552 (64%) said that providing a vaginal swab was at least as easy as providing a urine specimen. CONCLUSIONS: In this low-risk community-based cohort, bacterial vaginosis was not a strong risk factor for preterm birth.     

Serum cystyl aminopeptidase activity in the 36th week of pregnancy.

Serum cystyl aminopeptidase (CAS) activity was estimated at 36 weeks' gestation in 209 normotensive pregnancies. The highest activity was found in 31 women who had spontaneous deliveries before 38 weeks' gestation and the lowest in 76 women who were induced after term. The enzyme levels in 117 women who developed hypertension of pregnancy were higher than for normotensives; the highest levels were found in 32 women with pre-eclampsia. A correlation was found between serum CAS activity at 36 weeks' gestation and the birth weight of babies of women who went into spontaneous labour at term (277 to 283 days' gestation).     

Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

BACKGROUND: Bacterial vaginosis has been associated with preterm birth. In clinical trials, the treatment of bacterial vaginosis in pregnant women who previously had a preterm delivery reduced the risk of recurrence. METHODS: To determine whether treating women in a general obstetrical population who have asymptomatic bacterial vaginosis (as diagnosed on the basis of vaginal Gram's staining and pH) prevents preterm delivery, we randomly assigned 1953 women who were 16 to less than 24 weeks pregnant to receive two 2-g doses of metronidazole or placebo. The diagnostic studies were repeated and a second treatment was administered to all the women at 24 to less than 30 weeks' gestation. The primary outcome was the rate of delivery before 37 weeks' gestation. RESULTS: Bacterial vaginosis resolved in 657 of 845 women who had follow-up Gram's staining in the metronidazole group (77.8 percent) and 321 of 859 women in the placebo group (37.4 percent). Data on the time and characteristics of delivery were available for 953 women in the metronidazole group and 966 in the placebo group. Preterm delivery occurred in 116 women in the metronidazole group (12.2 percent) and 121 women in the placebo group (12.5 percent) (relative risk, 1.0; 95 percent confidence interval, 0.8 to 1.2). Treatment did not prevent preterm deliveries that resulted from spontaneous labor (5.1 percent in the metronidazole group vs. 5.7 percent in the placebo group) or spontaneous rupture of the membranes (4.2 percent vs. 3.7 percent), nor did it prevent delivery before 32 weeks (2.3 percent vs. 2.7 percent). Treatment with metronidazole did not reduce the occurrence of preterm labor, intraamniotic or postpartum infections, neonatal sepsis, or admission of the infant to the neonatal intensive care unit. CONCLUSIONS: The treatment of asymptomatic bacterial vaginosis in pregnant women does not reduce the occurrence of preterm delivery or other adverse perinatal outcomes.     

Identification and H(2)O(2) production of vaginal lactobacilli from pregnant women at high risk of preterm birth and relation with outcome

Lactobacilli, principally the strains that are hydrogen peroxide (H(2)O(2)) producing, may have a protective effect against vaginal colonization by pathogenic species such as those that cause bacterial vaginosis. Previous reports have also suggested that H(2)O(2)-producing lactobacilli in the vagina may protect pregnant women against ascending infection of the chorioamniotic membranes and uterine cavity. We report the identification and H(2)O(2) production of lactobacilli isolated from vaginal swabs collected at 20 weeks' gestation from a population of pregnant women at high risk of preterm birth. We also report the correlation between identification and H(2)O(2) production in relation to the outcomes of chorioamnionitis and preterm birth. Lactobacilli were identified by partial 16S rRNA gene sequencing. H(2)O(2) production by isolates was determined by a semiquantitative method. The most commonly isolated species were L. crispatus, L. gasseri, L. vaginalis and L. jensenii. Amounts of H(2)O(2) produced by lactobacilli varied widely. The presence of lactobacilli producing high levels of H(2)O(2) in the vagina of this population of pregnant women was associated with a reduced risk of bacterial vaginosis at 20 weeks' gestation and subsequent chorioamnionitis. L. jensenii and L. vaginalis produced the highest levels of H(2)O(2). We postulate that H(2)O(2)-producing lactobacilli are able to reduce the incidence of ascending infections of the uterus and the subsequent production of proinflammatory molecules which are important in the pathogenesis of chorioamnionitis and preterm birth.     

Successful pregnancy in a woman with Bloom syndrome

Bloom syndrome is a rare autosomal recessive disorder notable for increased chromosome fragility and an increased rate of somatic mutation. The clinical manifestations include small stature, a characteristic dermatologic lesion, and an excess incidence of malignancy. Fertility is generally reduced. A 19-year-old white woman with Bloom syndrome was successfully treated for preterm labor at 32 weeks' gestation, and ultimately delivered a healthy male infant at 35 weeks' gestation. Reports of pregnancy in women with Bloom syndrome are few. Despite reduced fertility, conception can occur, and women with Bloom syndrome should receive appropriate reproductive counseling to prevent unintended pregnancies and increased surveillance for preterm birth.     

Association between preterm birth and vaginal colonization by mycoplasmas in early pregnancy

To examine the association between colonization by two newly classified species of genital ureaplasmas (Ureaplasma parvum and U. urealyticum) in early pregnancy and subsequent late abortion or preterm birth at <34 weeks of gestation, four species of genital mycoplasmas--Mycoplasma genitalium, M. hominis, U. parvum, and U. urealyticum--as well as Chlamydia trachomatis and Neisseria gonorrhoeae were examined by PCR-based methods in a prospective cohort study of 877 women with singleton pregnancies at <11 weeks of gestation. Antibiotics were used only in cases in which C. trachomatis and/or N. gonorrhoeae was detected. Multivariate logistic-regression analysis was used to assess independent risk factors after taking maternal low body weight and past history of preterm birth into account. M. genitalium, M. hominis, U. parvum, U. urealyticum, C. trachomatis, and N. gonorrhoeae were detected in 0.8%, 11.2%, 52.0%, 8.7%, 3.2%, and 0.1% of these 877 women, respectively. Twenty-one (2.4%) women experienced late abortion or preterm birth at <34 weeks of gestation. Three factors-detection of U. parvum in the vagina (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1 to 8.5); use of antibiotics, such as penicillin and cefatrizine, for incidental inflammatory complications before 22 weeks of gestation (OR, 4.2; 95% CI, 1.6 to 10.0); and past history of preterm birth (OR, 10.4; 95% CI, 2.7 to 40.5)-were independently associated with late abortion and preterm birth. In conclusion, vaginal colonization with U. parvum, but not U. urealyticum, is associated with late abortion or early preterm birth.     

Early rapid growth,early birth: Accelerated fetal growth and spontaneous late preterm birth

The past two decades in the United States have seen a 24% rise in spontaneous late preterm delivery (34–36 weeks) of unknown etiology. This study tested the hypothesis that fetal growth was identical prior to spontaneous preterm (n = 221, median gestational age at birth 35.6 weeks) and term (n = 3706) birth among pregnancies followed longitudinally in Santiago, Chile. The hypothesis was not supported: Preterm‐delivered fetuses were significantly larger than their term‐delivered peers by mid‐second trimester in estimated fetal weight, head, limb, and abdominal dimensions, and they followed different growth trajectories. Piecewise regression assessed time‐specific differences in growth rates at 4‐week intervals from 16 weeks. Estimated fetal weight and abdominal circumference growth rates slowed at 20 weeks among the preterm‐delivered, only to match and/or exceed their term‐delivered peers at 24–28 weeks. After an abrupt growth rate decline at 28 weeks, fetuses delivered preterm did so at greater population‐specific sex and age‐adjusted birth weight percentiles than their peers from uncomplicated pregnancies (P < 0.01). Growth rates predicted birth timing: one standard score of estimated fetal weight increased the odds ratio for late preterm birth from 2.8 prior to 23 weeks, to 3.6 (95% confidence interval, 1.82–7.11, P < 0.05) between 23 and 27 weeks. After 27 weeks, increasing size was protective (OR: 0.56, 95% confidence interval, 0.38–0.82, P = 0.003). These data document, for the first time, a distinctive fetal growth pattern across gestation preceding spontaneous late preterm birth, identify the importance of mid‐gestation for alterations in fetal growth, and add perspective on human fetal biological variability. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.     

Decreased proinflammatory cytokines in cervicovaginal fluid, as measured in midgestation, are associated with preterm delivery

PROBLEM: The main aim of this study was to investigate the relationship between selected proinflammatory cytokines [interleukin IL-1 alpha (IL-1alpha), IL-1 beta (IL-1beta), IL-6 and IL-8] concentrations in cervicovaginal fluid, as measured in midgestation, and the risk of subsequent preterm delivery. METHOD OF STUDY: Cervicovaginal fluids were obtained from a cohort of 114 pregnant women at 22-34 weeks' gestation and analyzed for the concentrations of IL-1alpha, IL-1beta, IL-6 and IL-8 using enzyme-linked immunosorbent assay technique. Lower genital tract microbiology was diagnosed using Gram stain method and by culture. RESULTS: Mean gestational age at the time of sampling was 29.0 weeks. Mean time between sampling and delivery was 9.3 weeks (S.D. 4.7). Median cervicovaginal concentrations of IL-1alpha, IL-1beta, IL-6 and IL-8 did not differ between preterm and term delivery group. Women with lower genital tract pathological flora and IL-1alpha concentration below 25th percentile presented significant risk of subsequent preterm delivery as compared with women with no low cytokines (OR = 10.7; 95% CI, 2.0-58.1). Women with more than one cytokine' low concentration (below 25th percentile) presented an increased risk of preterm delivery--OR = 11.8 (95% CI, 1.8-78.0). CONCLUSIONS: The midgestation cytokines' measurement in cervicovaginal fluid of pregnant women could be useful for prediction of preterm delivery only among women with lower genital tract pathological flora.     

超声测量前置胎盘孕妇子宫颈管长度预测阴道出血与早产

应用超声测量前置胎盘孕妇子宫颈管长度,探讨其与阴道出血和早产的关系。方法 将2005年1月至2010年1月在本院产检并分娩的82例前置胎盘孕妇按孕周28～30周、31～33周、34 ～ 36周分为3组,采用超声测量各组孕妇子宫颈管长度,记录3组前置胎盘孕妇子宫颈管长度＞30 mm和≤30 mm例数,观察各组子宫颈管长度＞30 mm和≤30 mm孕妇出现的阴道出血、下腹痛、宫缩临床症状的例数并统计对比早产率、平均分娩孕周、新生儿出生体质量、新生儿窒息率。分别绘制子宫颈管长度预测阴道出血和早产的ROC曲线,计算曲线下面积和最佳临界点。结果 3组前置胎盘孕妇子宫颈管长度＞30 mm和≤30 mm的例数分别为28～30周组:20例、8例,31～33周组:19例、11例,34～36周组:11例、13例。子宫颈管长度≤30 mm的前置胎盘孕妇阴道出血率、早产率均明显高于子宫颈管长度＞30 mm者(28 ～ 30周组:阴道出血率87.50％比20％,早产率75％比15％;31～33周组:阴道出血率72.73％比26.32％,早产率63.64％比21.05％; 34 ～ 36周组:阴道出血率69.23％比27.27％,早产率38.46％比18.18％;均P＜0.05),3组出现下腹痛和官缩临床症状的比例也是子官颈管长度≤30 mm的前置胎盘孕妇高于子宫颈管长度＞30 mm者;3组子宫颈管长度≤30 mm的孕妇平均分娩孕周、新生儿出生体质量则低于子宫颈管长度＞30 mm者(均P＜0.05),新生儿窒息率在28 ～ 30周、31～ 33周组子宫颈管长度≤30 mm的孕妇高于子宫颈管长度＞30mm者(均P＜0.05),而34～36周组的孕妇均未出现新生儿窒息。子宫颈管长度预测阴道出血及早产的ROC曲线下面积分别为73.4％、65.3％,30.5 mm为预测的最佳临界点。结论 超声测量前置胎盘孕妇子宫颈管长度可作为预测阴道出血与早产的一种方法。     

Uterine artery Doppler velocimetry in the prediction of adverse obstetric outcomes in unexplained MSAFP elevations

Unexplained maternal serum-fetoprotein (MSAFP) elevation has been known to be associated with adverse obstetric outcomes, however it is not sufficiently useful as a screening test. This study was undertaken to determine whether uterine artery Doppler velocimetry could define a subset of patients with an elevated MSAFP level in whom complications of pregnancy might develop. The subjects included 179 women between 26 and 28 weeks' gestation with MSAFP > or = 2.5 multiples of the median, in whom either the presence of an early diastolic notch or a resistance index 0.6 was considered as an abnormal Doppler velocimetry finding. Those subjects who displayed abnormal Doppler velocimetry findings showed an increased incidence of preeclampsia, preterm birth, IUGR, and IUFD compared to those subjects with only elevated MSAFP (p < 0.05). No differences were observed in the incidence of LBW. Positive predictive values of adverse obstetric outcomes were significantly higher in the group having both elevated MSAFP and abnormal Doppler velocimetry compared to the group with only elevated MSAFP (p < 0.05). Uterine artery Doppler velocimetry in the second trimester can improve the value of unexplained MSAFP elevation in the prediction of adverse obstetric outcomes.