Association of amniotic fluid index with estimated fetal weight.

OBJECTIVE: The relationship between amniotic fluid volume and gestational age has been described previously. The association of body weight and urine output has been observed in human neonates. Our goal was to assess the correlation of the amniotic fluid index (AFI) with estimated fetal weight (EFW) in the third trimester. METHODS: We conducted a retrospective observational study on 426 pregnant women with singleton gestations who were referred to our unit for sonographic evaluation in the third trimester. The AFI, EFW, and EFW percentile corrected for gestational age were evaluated. The sonographic examinations were stratified into 3 gestational age categories: 28 through 33.9 weeks, 34 through 37.9 weeks, and 38 weeks and later. Maternal and fetal outcome variables were collected from medical records. Linear regression, Mann-Whitney U, and Kruskal-Wallis tests were used for statistical analysis. RESULTS: There was no significant relationship between the AFI and EFW in the entire group of patients (R = 0.08; P = .096). There was a significant relationship between the AFI and EFW after 38 weeks' gestation (R = 0.30; P = .003). In addition, in female fetuses the EFW percentile correlated with higher AFI values at all gestational ages (R = 0.31; P < .001); this, however, was not observed in male fetuses. CONCLUSIONS: There is no relationship between the AFI and EFW during the third trimester, although a positive relationship between the AFI and EFW was noted late in gestation. In pregnancies with female fetuses, the AFI was positively associated with EFW percentile before 38 weeks' gestation.     

Use of the amniotic fluid index combined with estimated fetal weight within 10 days of delivery for prediction of macrosomia at birth.

OBJECTIVE: The purpose of this study was to assess the value of combining the sonographically estimated fetal weight (EFW) and amniotic fluid index (AFI) measured within 10 days of term delivery for prediction of macrosomia at birth. METHODS: Prospective sonographic fetal biometric measurements and delivery ward data of a single center, uploaded separately over a 4-year period, were retrospectively linked to yield an unselected sample of nondiabetic pregnancies with live-born term neonates. RESULTS: Of the 1925 pregnancies evaluated, 140 (7.2%) were macrosomic (birth weight > or =4000 g). The AFI was significantly higher in the macrosomic group (P < .001). On receiver operating characteristic curve analysis, the area under the curve was larger for predictions based on the EFW alone than on the AFI. An EFW of 4000 g or higher had a positive predictive value of 46.6% for macrosomia at birth. Use of the previously suggested combined EFW and AFI cutoffs of 3689 g and 119 mm, respectively, yielded a positive predictive value of 30.3%. CONCLUSIONS: Combined use of the EFW and AFI rather than the EFW alone does not improve prediction of macrosomia at birth.     

Effect of fetal movement on the amniotic fluid index in diamniotic twin gestations

Fetal movement changes the size and location of amniotic fluid pockets during measurement of the amniotic fluid index. In singleton gestations, the effect of redistributing the fixed intrauterine fluid volume on the amniotic fluid index is clinically insignificant. In this study, we tested the hypothesis that the index in twin pregnancies is unaffected by fetal movement. A single examiner prospectively determined the amniotic fluid index before and after three discrete episodes of movement by both fetuses of 82 diamniotic twin pregnancies referred for obstetric sonograms between 20 and 38 weeks' menstrual age. A reliable blinded examiner provided a second post-movement measurement as a control. Data were analyzed by the paired t-test. The mean change in the amniotic fluid index after fetal movement was 2.1 ± 0.2 cm and 3.7 ± 0.3 cm for post-movement determinations by the same and blinded examiners, respectively (p < .001). Interobserver variation was 3.5 cm. Intraobserver variation was 1.8 cm for the first examiner and 2.2 cm for the second examiner. Therefore, interobserved and intraobserver variation can account for the observed change in the amniotic fluid index following movement of both diamniotic twins. © 1997 John Wiley & Sons, Inc. J Clin Ultrasound 25:255–257, 1997     

Correlation between fetal gastric size and amniotic fluid volume

PURPOSE: Since abnormal conditions of the fetal digestive tract may alter both amniotic fluid volume and fetal gastric volume, we sought to determine whether amniotic fluid volume is correlated with fetal gastric volume in normal pregnancy. METHODS: A total of 280 fetal gastric size measurements were made prospectively from routine sonographic examinations of women with normal singleton pregnancies between 16 and 42 weeks of gestation. The fetal stomach was defined as the largest area including the pyloric site on transverse or oblique real-time sonographic scans. Gastric volume was calculated according to the formula for a prolate ellipsoid. The amniotic fluid index (AFI) was used for the evaluation of amniotic fluid volume. RESULTS: Both fetal gastric volume and AFI were significantly correlated with gestational age (R2= 0.422 and R2= 0.128, respectively). Only a weak correlation was found between gastric volume and AFI (R2= 0.036, p <0.001). On multivariate linear regression analysis adjusting for gestational age and fetal biometric measurements, gastric volume was not an independent and significant predictor of AFI. CONCLUSIONS: Although sonographically determined fetal gastric volume measurements appear to be useful in the assessment of fetal digestive tract anomalies, fetal gastric volume has no clinically significant effect on the amniotic fluid volume in normal pregnancy.     

羊水量异常的超声诊断与胎儿畸形的关系

目的 探讨羊水量异常与胎儿畸形的关系.方法 回顾分析2004年3月至2006年11月在本院进行二维及三维超声检查34 900例20周以上的胎儿,其检出羊水量异常160例,并研究分析羊水量多少与胎儿畸形的关系.结果 160例羊水量异常中,羊水过多100例,羊水过少60例,二者畸形的发生率分别为37%、31.6%.结论 超声是诊断羊水量异常的首选方法,而且还能发现胎儿畸形,进一步证明羊水量异常与胎儿畸形的发生密切相关.     

The effects of maternal position on the amniotic fluid index.

OBJECTIVE: We investigated the influence of maternal positioning on the measurement of the amniotic fluid index (AFI) in third-trimester pregnancies. We wanted to determine whether a change in the position of the women, from supine-flat to supine-elevated, would influence the measurement of the AFI. METHODS: Each patient had AFI measurements obtained in both positions by the same investigator. RESULTS: We determined the values of the amniotic fluid index to be consistent in both positions for pregnancies with normal AFI measurements. CONCLUSIONS: Measurements of the amniotic fluid did not appear to be influenced by maternal position in the third trimester when the AFI was in the normal range.     

地塞米松预防羊水栓塞的临床价值

目的：探讨静脉注射地塞米松预防阴道分娩、剖宫产术羊水栓塞（AFE）的临床疗效。方法：选择2001年3月-2007年12月在湖北省天门市妇幼保健院产科住院分娩的孕妇10728例作为试验组,与同期在该院产科住院分娩的孕妇10812例作为对照组,试验组在阴道分娩破膜前10rain和剖宫产于手术前10min静脉注射地塞米松10mg,高危分娩和高危手术者另静脉滴注地塞米松10～20mg,对照组不用地塞米松,观察2组AFE的发病率、产后出血的发病率、新生儿窒息的发病率。结果：AFE的发病率：试验组0．19‰,对照组1．02‰,比较差异有统计学意义（P〈0．05）;产后出血的发病率：试验组0．98％,对照组6．49％,比较差异有统计学意义（P〈0．01）;新生儿窒息的发病率：试验组5．87％,对照组17．19％,比较差异有统计学意义（P〈0．01）。结论：分娩前和手术前静脉注射地塞米松可起到预防AFE的作用,同时还可降低产后出血和新生儿窒息的发病率,可作为阴道分娩和手术前的预防性用药推广应用。     

The accuracy of ultrasound evaluation of amniotic fluid volume in singleton pregnancies: The effect of operator experience and ultrasound interpretative technique

The objective of this study was to evaluate the effect of operator experience and ultrasound interpretation technique on the accuracy of ultrasound estimates of amniotic fluid volume. Ultrasound evaluation was carried out by an obstetric resident, a nurse sonographer, a maternal-fetal medicine fellow, and a maternal-fetal medicine staff member to subjectively estimate (visual interpretation without sonographic measurements) amniotic fluid volume in 63 pregnancies. Amniotic fluid volume was also evaluated using ultrasound measurements based on the largest vertical pocket technique, the amniotic fluid index, and the two-diameter pocket method. The accuracy of these ultrasound estimates was assessed by comparing the ultrasound results to actual amniotic fluid volume as determined by a dye-dilution technique. For analysis, amniotic fluid volumes were classified as oligohydramnios, normal, or hydramnios using established volumetric criteria for singleton pregnancies. Subjective estimates ranged from 65% to 70% correct and did not differ by operator experience except for the more accurate diagnosis of hydramnios by the maternal-fetal medicine staff. The three sonographic measurements were similar in overall accuracy (59–67%). The two-diameter pocket method was, however, significantly more accurate in identifying oligohydramnios. It appears that neither operator experience nor sonographic technique greatly affects the accuracy of ultrasound estimates of amniotic fluid volume. © 1997 John Wiley & Sons, Inc. J Clin Ultrasound 25:249–253, 1997     

1例剖宫产术后羊水栓塞的急救与护理

目的通过对1例剖宫产术后羊水栓塞的急救,探讨羊水栓塞的抢救方法,以提高羊水栓塞救治水平。方法对我院1例羊水栓塞致产后大出血的发病诱因、临床表现、实验室检查及治疗结果进行分析。结果1例患者抢救成功痊愈出院。结论早期识别、及时正确处理是提高产后发生羊水栓塞抢救成功的关键。     

1例剖宫产术后羊水栓塞的急救与护理

目的 通过对1例剖宫产术后羊水栓塞的急救,探讨羊水栓塞的抢救方法,以提高羊水栓塞救治水平.方法 对我院1例羊水栓塞致产后大出血的发病诱因、临床表现、实验室检查及治疗结果进行分析.结果 1例患者抢救成功痊愈出院.结论 早期识别、及时正确处理是提高产后发生羊水栓塞抢救成功的关键.     

羊水过少187例临床分析

目的：探讨羊水过少的早期诊断及处理与围产儿预后的关系。方法：对187例羊水过少(羊水过少组)患者的临床资料进行回顾性分析，并与同期正常分娩者(正常对照组)的围产儿情况进行比较。结果：187例羊水过少患者中，发生率为4．3％(187／4356)；羊水过少组的胎儿宫内发育迟缓、胎儿宫内窘迫、新生儿吸人性肺炎及新生儿窒息发生率均明显高于对照组(P均＜0．05)。产前B超羊水指数法(AFI法)诊断率为68．48％(129／187)，符合率为97．67％(126／129)。结论：应重视产前B超检查对羊水的动态监测；在分娩方式上．应结合是否合并高危因素、胎心监护以及宫颈条件等情况综合分析．采取必要的措施，尽量以剖宫产终止妊娠为宜。     

正常足月产妇羊水组织因子水平与妊娠高凝状态、羊水栓塞的关系研究

目的探讨正常足月产妇羊水中的组织因子(TF)水平与妊娠高凝状态及羊水栓塞的关系。方法选取2013年1月至2014年12月该院待产的正常足月妊娠产妇158例,检测产妇血浆、羊水、羊水上清液及羊水沉渣中的TF和组织因子途径抑制物(TFPI)水平。结果羊水沉渣TF水平为(1 409.36±120.34)ng/L,明显高于血浆、羊水及羊水上清液水平,差异有统计学意义(P0.05);血浆TF水平为(30.17±6.49)ng/L,明显低于羊水各标本水平,差异有统计学意义(P0.05);羊水沉渣TFPI水平为(9.46±1.77)g/L,明显低于血浆、羊水及羊水上清液水平,差异有统计学意义(P0.05);血浆TFPI水平为(22.19±5.16)g/L,明显高于羊水各标本(P0.05);羊水及羊水上清液TF和TFPI水平差异无统计学意义(P0.05);羊水、羊水上清液、羊水沉渣中TF与TFPI呈负相关关系(P0.05),其中羊水沉渣相关性最强(r=-0.903,P0.05),血浆标本TF与TFPI无相关性(P0.05)。结论正常足月产妇羊水TF含量较高,而TFPI较低,可能在羊水栓塞的发生机制中起一定的临床作用。     

Polymerase chain reaction in the detection of microbes in amniotic fluid

Intra-amniotic infection during pregnancy can be caused by bacteria, viruses or protozoa, Toxoplasma gondii for example. Bacterial intrauterine infections are connected with premature birth, premature rupture of fetal membranes, and infective complications of both the mother and the newborn. Viral infections and Toxoplasma gondii can cause fetal malformations and illness with serious sequelae to the infant or fetal death in utero. Determining the causative agent is important and often greatly affects the prognosis of the newborn. Amniotic fluid is in most cases easily and safely obtainable during the second and third trimester and can be used in several microbiological assays. These include bacterial and viral cultures, Gram staining, quantitative assays for immunoglobulins or cytokines, and polymerase chain reaction (PCR) for detecting microbial DNA. This review concentrates on broad-spectrum or universal bacterial PCR for detection of bacterial DNA in amniotic fluid and on PCR assays for certain clinically important viruses and for Toxoplasma gondii.