Incidence of Chromosomopathies and Cystic Fibrosis Mutations in Second Trimester Fetuses with Isolated Hyperechoic Bowel

Objective: Fetal echoic bowel can be a normal second trimester ultrasonographic finding which usually disappears by 20 weeks on serial sonograms. Recent studies have suggested a possible association of hyperechoic fetal bowel with chromosomopathies and cystic fibrosis. The aim of our study is to determine the incidence of chromosomopathies and cystic fibrosis mutations among the fetuses with isolated hyperechoic bowel.

Methods: Sixteen fetuses with isolated echoic bowel were detected: 13 fetuses S20 weeks gestation (group I) and 3 fetuses at 20-26 weeks gestation (group II). Cytogenetic studies were performed in all 16 cases and 11 families had deoxyribonucleic acid-based risk assessment for cystic fibrosis. The echogenity of bowel was that of surrounding bone.

Results: Two cases of trisomy 21 and 1 case of trisomy 13 were detected (18.7%). The other ultrasonographic markers begin to appear after 21 weeks gestation in fetuses with trisomy 13. Two of 3 pregnant women with pathological karyotype were younger than 35 years. One of 11 cases (9%) was found to be a heterozygote carrier for ΔF508 mutation.

Conclusions: Isolated hyperechoic bowel in the second trimester was found to be associated with a significantly higher risk of fetal aneuploidy.     

Fetal heart rate after vibroacoustic stimulation

Objective

To define reference ranges for fetal heart rate (FHR) parameters after vibroacoustic stimulation (VAS) according to gestational age by determining the relationship between FHR and gestational age using a computerized analysis system.

Methods

Data were analyzed from 3453 women using 10-minute observational recordings during nonstress testing (NST) and VAS testing. FHR parameters were analyzed according to gestational age.

Results

All FHR parameters were related to gestational age except for mean baseline FHR, which did not vary significantly with gestational age. All other parameters followed trends similar to the NST results, except for decelerations.

Conclusion

FHR parameters after VAS differed significantly according to gestational age. The results suggest that the gestational age of the fetus should be considered when interpreting FHR patterns after VAS.     

Serum relaxin levels are reduced in pregnant women with a history of recurrent miscarriage, and correlate with maternal uterine artery Doppler indices in first trimester

Objectives

Defective implantation is a mechanism for recurrent pregnancy loss (RPL). We sought to determine whether the serum expression of human relaxin-2 (RLX) is impaired in women with a history of RPL.

Study design

Employing a prospective case-controlled design we studied 20 pregnant women with a history of RPL and 20 age-matched women with no history of RPL (NRPL). We measured serum relaxin-2 levels by ELISA at 6–8, 10–12, 20, and 34 weeks gestation and in cord blood, and maternal uterine artery Doppler resistance index (RI) at ≥10 weeks gestation.

Results

Relaxin rose to a peak at 12 weeks, and gradually declined towards term. At all gestations, women with a history of RPL had lower RLX levels than women without. At 10–12 weeks gestation, uterine artery RI correlated with serum RLX for both RPL and NRPL. In the NRPL group at 10–12 weeks the presence of a notched waveform was associated with higher RLX levels than the absence of a notch (mean 2.1 ng/ml vs. 1.3 ng/ml, P < 0.05) and also at 20 weeks (2.1 ng/ml vs. 0.95 ng/ml, P < 0.05) but no such difference was seen in the RPL group. Umbilical venous RLX was 4-fold higher in the RPL group than the NRPL group.

Conclusion

Women with a history of RPL demonstrate attenuated levels of serum RLX across all pregnancy trimesters. How dysregulated RLX metabolism may contribute to adverse pregnancy outcome in RPL requires further investigation.     

Monitoring fetal growth in settings with limited ultrasound access

Abnormal fetal growth significantly increases neonatal mortality and the risk of stillbirth. This creates the need for accurately monitoring fetal growth in all pregnancies regardless of the risk status. Several methods used in clinical practice include abdominal palpation, symphysio-fundal height measurements, and obstetric ultrasound. Of these, obstetric ultrasound remains the most reliable and objective way to monitor fetal growth. However, in most low-resource areas, access to obstetric ultrasound remains poor and this leaves the two as the only options available. This not only has effect on fetal growth monitoring but more importantly on the accuracy of pregnancy dating. To improve the current situation, we propose strategies for training of health workers, educating the public on importance of obstetric ultrasound, and improving access to basic equipment. However, interim solutions have to be implemented hand in hand with other strategies to ensure universal access to ultrasound technology for fetal growth monitoring.     

Amniotic Fluid Glycine/Valine Ratio Is Elevated in Fetuses with Growth Retardation

Alterations in the amnio acid content of fetal and neonatal cord blood characteristic of chronic starvation have been identified in growth-retarded offspring. We hypothesized that these changes in amino acid patterns, specifically an increase in the glycine/valine ratio, would be present in the amniotic fluid of growth-retarded fetuses. Amniotic fluid specimens from 63 singleton pregnancies in the third trimester (range 33-39 weeks) were examined. Twenty-five pregnancies were complicated by fetal growth retardation (FGR) which was suspected by ultrasound and confirmed at birth. Amniocenteses were performed for routine clinical indications. Amino acid analysis was performed on prepared amniotic fluid specimens by high-pressure liquid chromatography. The glycine/valine ratio in amniotic fluid as a function of gestational age was compared between growth-retarded and control (C) groups by analysis of covariance. Amniotic fluid from growth-retarded fetuses demonstrated a significantly higher glycine/valine ratio than amniotic fluid from controls (FGR 3.25 ± 0.15 vs C 2.54 ± 0.12, adjusted mean ± SE P < 0.001) with no difference in regression slope. In conclusion, amniotic fluid glycine/valine ratios are elevated in growth-retarded fetuses. We speculate that these patterns may assist in the identification of the substrate-deprived, growth-retarded fetus.     

重度子痫前期并发腹水的特点及终止妊娠的时机

目的:通过分析重度子痫前期并发腹水患者的临床特点,探讨终止妊娠的时机。方法:回顾分析358例重度子痫前期患者的临床资料,根据是否并发腹水分为:腹水组(64例)和非腹水组(294例)。分析两组孕妇一般情况、分娩方式、合并症及并发症(包括子痫、HELLP综合征、肝肾功能不全、心功能不全、低蛋白血症、胎盘早剥、产后出血、产褥感染)。收集两组围产儿(腹水组76例,无腹水组314例)的临床资料,按胎龄分为<32周、32～33+6周、34～35+6周和≥36周,分别比较两组小于胎龄儿(SGA)的发生率和死亡率。结果:(1)腹水组入院孕周和分娩孕周均明显早于无腹水组[入院(31.1±2.2)周vs(35.1±3.1)周],分娩(32.1±2.2)周vs(36.2±1.3)周,P均<0.05)。腹水组系统产前检查率显著低于无腹水组(25.0%和46.3%,P<0.05)。腹水组低蛋白血症(100.0%vs 46.9%)、肝肾功能不全(31.2%vs 8.2%)、HELLP综合征(9.4%vs2.0%)、产后出血(18.8%vs 2.0%)发生率均显著高于无腹水组(P均<0.05)。(2)腹水组围产儿SGA发生率与无腹水组的差异无显著性(60.5%vs 29.3%,P>0.05〉;腹水组不同胎龄围产儿SGA发生率均高于同胎龄无腹水组,但仅胎龄≥36周时差异有统计学意义(77.8%vs 48.2%,P<0.05);腹水组中,胎龄≥36周的围产儿SGA发生率最高(P<0.05)。(3)腹水组围产儿死亡率显著高于无腹水组(31.6%vs 5.7%,P<0.05)。除胎龄34～35+6周组,其余各胎龄组的腹水组围产儿死亡率均显著高于同胎龄无腹水组(P<0.05);腹水组中,胎龄<32周的围产儿死亡率显著高于其他胎龄组(P<0.05)。结论:重度子痫前期并发腹水发病早,并发症多,母儿预后不佳。腹水是重度子痫前期的一个危险信号,应引起产科医生的高度重视。对于重度子痫前期并发腹水者,应实时终止妊娠。     

Placental Thickness: Its Correlation with Ultrasonographic Gestational Age in Normal and Intrauterine Growth-Retarded Pregnancies in the Late Second and Third Trimester

Objective

The aim was to study the correlation of placental thickness, measured at the level of the umbilical cord insertion, with the ultrasonographic gestational age in normal and IUGR pregnancies in the late second and third trimester.

Materials and Methods

A total of 498 patients were observed for correlation of the placental thickness with ultrasonographic gestational age and their outcomes by dividing them into Group A (outcome fetal weight < 2,500 g, n = 122) and Group B (fetal weight > 2,500 g, n = 376). The mean placental thickness was calculated at the umbilical cord insertion in both groups along with ultrasonographic fetal age and estimated fetal weight. The mean values of placental thickness along with respective standard deviation were calculated from the 24th to 39th week of gestational age.

Results

A positive correlation was observed between placental thickness and ultrasonographic gestational age in both groups (p value of 0.01), with Pearson’s correlation coefficient (“r”) values of 0.325 in Group A and 0.135 in Group B. Regression analysis yielded linear equations of relationship with placental thickness and gestational age in both groups. The placental thickness was also found to be lower in Group A between 26 and 27 weeks and 30 and 31 weeks, having mean values of 2.48 ± 0.063 cm (p value of 0.042) and 2.76 ± 0.552 (p value of 0.05) in Group A as compared to 3.04 ± 0.25 and 3.13 ± 0.183 cm in Group B.

Conclusions

Placental thickness measured at the level of umbilical cord insertion can be used as an accurate sonographic indicator in assessment of gestational age in singleton pregnancies because of its linear correlation.     

Pathological Uterine Perfusion in the Second Trimester Is Not Associated with Neutrophil Activation

Objective: Preeclampsia and intrauterine growth retardation (IUGR) are associated with elevated concentrations of myeloperoxidase (MPO) and polymorphonuclear (PMN) elastase, which indicate maternal neutrophil activation. The aim of the study was to measure maternal MPO and PMN elastase plasma concentrations in second trimester pregnancies with pathological uterine perfusion that are a high risk group for preeclampsia and IUGR, and compare them to normal controls. Methods: The study includes 25 pregnancies with normal and 25 pregnancies with pathological uterine perfusion. In both groups, doppler‐sonographic measurement of uterine perfusion was performed in the twenty‐first week of gestation. Maternal plasma concentrations of MPO and PMN elastase were measured using a specific ELISA for both enzymes. Results: The plasma MPO concentration of pregnant women with normal perfusion did not differ significantly from that of the group with pathological perfusion (27.4 ± 3.3 vs. 23.7 ± 2.0 ng/mL). Likewise, the plasma PMN elastase‐concentration also did not show a significant difference between the groups (5.7 ± 0.5 ng/mL normal vs. 8.0 ± 1.0 ng/mL pathological). Patients with pathological perfusion that later developed preeclampsia or IUGR (9/25) showed unchanged MPO and PMN elastase values in the second trimenon compared to those with pathological perfusion and normal outcome. Conclusions: Pathological uterine perfusion in the second trimester was not associated with maternal neutrophil activation. The measurement of the MPO and PMN elastase concentration suggested that neutrophil activation in preeclampsia or IUGR is a secondary effect of the disease rather than a primary pathophysiological factor.     

建立预测妊娠期高血糖患者分娩巨大儿风险的列线图模型

目的：构建并验证妊娠期高血糖（hyperglycemia in pregnancy,HIP）患者分娩巨大儿风险的列线图模型。方法：回顾性分析2020年11月—2022年2月在太原市妇幼保健院分娩的HIP患者资料。采用多因素Logistic回归分析筛选发生巨大儿的独立影响因素,R软件构建列线图模型,采用受试者工作特征曲线下面积对该模型的效能进行评估,决策曲线分析（decision curve analysis,DCA）评估模型的临床使用价值。结果：(1)纳入1 098例HIP患者进行建模,其中92例（8.38%）孕妇分娩巨大儿。按7∶3比例将所有患者随机分为训练集（761例）和测试集（337例）。(2)多因素Logistic回归分析发现,经产妇（OR=3.19,95%CI:1.58～6.54,P=0.001）、高血压家族史（OR=2.28,95%CI:1.06～4.90,P=0.034）、妊娠前体质量指数（OR=1.18,95%CI:1.08～1.30,P<0.001）、双顶径（OR=13.52,95%CI:4.04～48.38,P<0.001）、腹围（OR=2.83,95%...     

早发型重度子痫前期患者分娩孕周对母儿结局的影响

目的 分析早发型重度子痫前期患者分娩孕周对母儿结局的影响,探讨终止妊娠的适宜时机.方法 回顾性分析于1999年7月1日至2009年6月30日的10年间在北京大学第一医院住院治疗并分娩的、终止妊娠孕周＞28周的单胎妊娠早发型重度子痫前期(发病孕周＜34周)患者221例的临床资料,按终止妊娠孕周分为3组,Ⅰ组为孕28～31周+6分娩,81例,Ⅱ组为孕32～33周+6分娩,78例,Ⅲ组为孕≥34周分娩,62例;比较3组患者的临床特点及母儿结局.结果 (1)围产儿结局:221例围产儿中共有13例失访,Ⅰ组9例,Ⅱ组3例,Ⅲ组1例.新生儿呼吸窘迫综合征(RDS)发生率Ⅰ组为26%(19/72),Ⅱ组为7%(5/75),Ⅲ组为10%(6/61),Ⅰ组明显高于其他两组,差异有统计学意义(P＜0.05);围产儿死亡率Ⅰ组为43%(31/72),Ⅱ组为28%(21/75),Ⅲ组为3%(2/61),Ⅰ组明显高于其他两组,差异也有统计学意义(P＜0.05);3组孕产妇并发症发生情况比较,差异均无统计学意义(P＞0.05).(2)围产儿死亡原因:因社会因素(家属放弃治疗)导致的围产儿死亡,Ⅰ组为26%(8/31),Ⅱ组为67%(14/21),Ⅲ组为1/2,3组分别比较,差异均有统计学意义(P＜0.05).结论 早发型重度子痫前期孕妇孕32周后分娩,早产儿RDS发病率明显下降,孕34周后分娩,围产儿死亡率明显下降.尽量减少社会因素的影响,有可能进一步提高早发型重度子痫前期围产儿的存活率.     

高龄妊娠宫内死胎原因分析

目的探讨高龄妊娠孕妇发生宫内死胎的原因。 方法本研究采用回顾性研究方法对2009年1月1日至2014年12月31日因宫内死胎(单胎)在广州医科大学附属第三医院妇产科住院治疗的339例患者临床资料进行分析,根据孕妇分娩年龄分为高龄组(≥35岁)和非高龄组(20～34岁),比较两组孕妇宫内死胎的原因。采用独立样本t检验、χ²检验或Fisher精确概率法对数据进行统计学分析。 结果高龄妊娠宫内死胎率为1.66%(61/3 670)比非高龄组1.10%(278/25 227)高,χ²＝8.670,P＝0.003;两组宫内死胎各种病因发生率的比较,差异均无统计学意义(P均>0.05);高龄组不明原因宫内死胎发生率27.87%(17/61)明显比非高龄组7.55%(21/278)高,χ²＝20.74,P＝0.000)。 结论高龄妊娠孕妇发生宫内死胎风险比非高龄者高,需加强对高龄妊娠人群孕期母胎监测。     

Fetal transcerebellar diameter measurement with particular emphasis in the third trimester: a reliable predictor of gestational age

OBJECTIVE: The purpose of this study was to validate prospectively a previous retrospectively established nomogram for the prediction of gestational age using transcerebellar diameter, especially in the third trimester. STUDY DESIGN: In a previous study, we retrospectively constructed a cross-sectional nomogram using transcerebellar diameter measurements in 24,026 well-dated singleton fetuses. In the present study, this nomogram was validated prospectively on the basis of patients who were seen between August 2002 and May 2003 and who were carrying non-anomalous and non-malformed singleton gestations between 14 and 42 weeks (n = 2597 gestations). The actual gestational age was then subtracted from the predicted gestational age, and the concordance between actual and predicted gestational ages was assessed based on the Pearson correlation (r). RESULTS: Concordance between the actual and predicted gestational age was high (r = 0.92; P < .0001). This agreement was superior in the second trimester (r = 0.93; P < .0001) than in the third trimester (r = 0.81; P < .001). Between 17 and 21 weeks, and between 22 and 28 weeks of gestation, the predicted gestational age ranged between 0 and 4 days, and between 0 and 2 days, respectively, of actual gestational age. Between 29 and 36 weeks of gestation, predicted gestational age was within 5 days of actual gestational age; at 37 weeks of gestation, the predicted gestational age was discrepant by 9 days. CONCLUSION: This prospective study demonstrates that transcerebellar diameter measurement is an accurate predictor of gestational age, even in the third trimester of pregnancy.     

妊娠中期羊水中相关炎症介质预测早产的研究进展

早产指妊娠满28周至不足37周分娩,早产儿的多器官系统发育不成熟和相关并发症是导致新生儿发病和死亡的重要原因。早产防治的困难性主要在其多病因性,目前其发病机制尚不明确,多项研究表明感染是其主要因素,感染产生的炎症介质通过多种途径最终诱发宫缩,从而促进早产。此前较多采用胎儿纤维连接蛋白（FFN）、经阴道宫颈管长度测定、血清中相关炎症介质的检测等预测晚期症状性早产的发生,而对中期预测早产应用受限。已证实绒毛膜羊膜炎时妊娠组织产生的相关炎症介质如白细胞介素6（IL-6）、IL-16、C反应蛋白（CRP）、脂联素、抗菌肽等直接进入羊水中,同时羊膜腔穿刺术常规用于产前诊断领域,因此通过对妊娠中期羊水中相关炎症介质的进一步研究有望为中期预测早产提供新的方法。     

血清学筛查与胎儿超声检查在18、13三体综合征产前诊断中的应用

目的:探讨利用孕妇血清学筛查和胎儿超声检查进行18、13三体综合征胎儿产前诊断的有效性。方法:①对78例(A组)产前血清学筛查18、13三体高风险孕妇,拒绝进行产前诊断的孕妇进行随访观察。②对56例(B组)首诊主诉胎儿超声检查有结构异常的孕妇、134例(C组)首诊主诉为产前血清学筛查胎儿18三体高风险的孕妇,于孕18～32周行羊膜腔穿刺羊水细胞培养,或脐血管穿刺脐血细胞培养染色体分析。结果:A组的18三体筛查高风险孕妇有2例出现B超检查结构异常而放弃妊娠,1例产后检查新生儿先天性心脏病。B组发现18三体3例,13三体3例,其他染色体异常7例,异常发现率23.21%(13/56);其中2例18三体合并有血清学筛查高风险。C组发现胎儿异常4例,其中2例确诊为18三体,异常发现率2.99%(4/134)。结论:孕妇血清生化指标筛查结合胎儿超声检查是产前检出18、13三体综合征胎儿的有效检查方法。     

妊娠期糖尿病患者氧化应激和EPO、FNRBC水平变化与胎盘组织学改变的关系

目的:探讨妊娠期糖尿病(GDM)患者氧化应激状态与脐血促红细胞生成素(EPO)和胎儿有核红细胞(FNRBC)水平变化及其与胎盘组织形态学异常发生率的关系。方法:选取28例GDM患者(GDM组)和22例正常妊娠妇女(正常对照组),采集其母血和脐血及对应的胎盘标本,检测母血和脐血氧化应激标志物丙二醛(MDA)、超氧化物歧化酶(SOD)浓度,脐血EPO浓度和FNRBC计数,同时对胎盘组织进行病理学检测。结果:GDM组患者母血和脐血中的MDA及脐血中EPO浓度和FNRBC计数明显高于正常对照组(P<0.05),SOD浓度较正常对照组明显降低(P<0.05)。GDM组患者胎盘病理检查提示,与正常对照组相比:绒毛成熟不良、干绒毛小动脉增厚和绒毛间质毛细血管充盈明显的发生比例增加(P<0.05),并且母血和脐血中的MDA浓度与胎盘绒毛成熟不良的发生比例呈正相关(P均<0.05)。结论:胎盘绒毛发育和成熟的复杂过程可能受母胎氧化应激与抗氧化环境的影响,胎盘病理组织学显示GDM时绒毛血管发育与成熟的异常可能导致胎儿缺氧和不良后果。     

Fetal color-coded tissue Doppler echocardiography: experiences with the "tracking method" in normal fetuses

Objective

Ultrasound-based tissue Doppler imaging has opened new perspectives for non-invasive quantification of global, as well as regional, myocardial function. We therefore studied fetal hearts using the “tracking method” in order to assess its feasibility and changes of fetal myocardial velocities throughout gestation.

Study design

In 89 healthy fetuses color-coded tissue Doppler echocardiography (TDE) was prospectively conducted for further offline-analysis of global and regional myocardial function of the basal segment. Maximum tissue velocities at systole (S), in the early filling phase of diastole (E) and during atrial contraction (A) were estimated from three consecutive cardiac cycles.

Results

Within a selected time limit of 15 min, raw data acquisition was possible in 60 of the 89 fetuses (67%). From the stored samples, velocities of S, E and A-wave could be obtained in 76% with good reproducibility for septal and right wall velocities. During gestation all velocities increased but to a greater extent at the right and left ventricular wall compared to the interventricular septum. The A-wave velocity was higher than E-wave velocity in all basal segments. Throughout gestation, the increase in E-wave was higher, resulting in an increase of the E-wave/A-wave ratio.

Conclusion

Tissue Doppler echocardiography using the tracking method in fetal hearts is practical during routine clinical examination, but it is time consuming and requires highly experienced observers The knowledge of myocardial velocities in normal pregnancies is essential in detecting pathologies.     

Obstetric and perinatal outcome in women with twin pregnancy and gestational diabetes

Objective: The aim of this study was to evaluate pregnancy complications and obstetric and perinatal outcomes in women with twin pregnancy and GDM. Study Design: An observational multicentre retrospective study was performed and 534 pregnant woman and 1068 twins infants allocated into two groups, 257 with GDM and 277 controls, were studied. Main Outcome Measures: Pregnant women characteristics, hypertensive complications, preterm delivery rate, mode of delivery and birthweight were analysed. Results: Pregnant women with GDM were older (p?<?0.001) and had higher body mass index (p?<?0.001) than controls. GDM was associated with higher risk of prematurity in twin pregnancy (odds ratio 1.64, 95% confidence interval [1.14–2.32], p?=?0.005). This association was based on the association with other pregnancy complications. Birthweight Z-scores were significantly higher in the GDM group (p?=?0.02). The rate of macrosomia was higher in the GDM group (p?=?0.002) and small for gestational age (SGA) babies were significantly less frequent (p?=?0.03). GDM was an independent predictor of macrosomia (p?=?0.006). Conclusion: The presence of GDM in twin pregnancy was associated with a higher risk of hypertensive complications, prematurity and macrosomia, but significantly reduces the risk of SGA infants. Prematurity was related to the presence of other associated pregnancy complications.     

Perinatal outcome associated with oligohydramnios in uncomplicated term pregnancies

Purpose In high-risk pregnancies, oligohydramnios is frequently used to identify fetuses at risk of an adverse outcome. The purpose of this study was to evaluate the effect of oligohydramnios on perinatal outcome in uncomplicated pregnancies between 40.0 and 41.6 weeks.Methods From January 1997 to December 2000 all uncomplicated pregnancies reaching 40.0 weeks' gestation with a singleton non-malformed fetus and reliable dating underwent monitoring with serial determination of amniotic fluid index (AFI) and biophysical profile. Labor was induced for AFI 5 cm, biophysical profile score of 6 or less, rise in maternal blood pressure >140/90 mm Hg, or gestational age of 42.0 weeks. Perinatal outcome was compared between cases with AFI 5 cm and those with AFI >5 cm using Chi-square or Fisher's exact test for categorical variables, Student's t-test for continuous variables, and logistic regression analysis. A two-tailed p value <0.05 or an odds ratio (OR) with 95% confidence interval (CI) not inclusive of the unity was considered significant.Results Three thousand and forty-nine women met the inclusion criteria, 341 of which (11%) had an AFI 5 cm. Gestational age at delivery, rates of nulliparity and induction of labor were significantly different between cases with oligohydramnios and those with normal AFI (all p<0.001). Rates of cesarean delivery for non-reassuring fetal testing (8.2% vs. 3.9%, p<0.001) and of neonates with birth weight <10th percentile (13.2% vs. 5.5%, p<0.001) were significantly higher in the AFI 5 cm group compared with the AFI >5 cm. No significant differences were identified between the two groups in rates of meconium-stained amniotic fluid, 5-min Apgar score <7, or umbilical artery pH <7. Logistic regression analysis demonstrated that the association between oligohydramnios and rate of cesarean delivery for non-reassuring fetal testing lost significance after controlling for gestational age at delivery, nulliparity and induction of labor, whereas the association between AFI 5 cm and low birth weight centiles remained statistically significant (OR=2.2, 95% CI 1.5, 3.2).Conclusion In conclusion, in uncomplicated pregnancies at 40.0 to 41.6 weeks, oligohydramnios is independently associated with a higher risk of low birth weight centile.