双胎妊娠生长不一致的诊治

双胎生长不一致是双胎妊娠特有并发症,发生原因有多方面,无论单绒毛膜还是双绒毛膜双胎的不一致,胎盘和脐带因素越来越受关注.期待处理不仅仅是监测发展及适时终止妊娠,针对改善胎盘功能的抗凝治疗等主动性干预在目前还需更多探索.     

双胎妊娠一胎宫内死亡12例临床分析

目的:探讨双胎妊娠一胎宫内死亡的发生率、发生原因.方法:回顾性分析我院2006年1月至2011年5月间12例双胎妊娠一胎宫内死亡的临床资料.结果:我院双胎妊娠一胎宫内死亡的发生率为3.7％.死亡原因:脐带及胎盘因素6例,合并重度子痫前期2例,双胎输血综合征1例,合并妊娠期糖尿病1例,原因不明1例.结论:双胎妊娠一胎宫内死亡最常见的死因是脐带胎盘因素,孕中、晚期双胎妊娠一胎宫内死亡可保守期待治疗,应严密监测母体及存活儿情况,以决定孕妇的分娩时机和分娩方式.     

胎儿脑损伤的危险因素

胎儿脑损伤的危险因素包括母体因素、胎儿因素及胎盘因素,其中母体因素包括妊娠期高血压疾病、妊娠期糖尿病、妊娠期肝内胆汁淤积症、宫内感染等;胎儿因素包括胎儿生长受限(FGR)、单绒毛膜双胎中的复杂性双胎等;胎盘因素包括胎盘早剥。加强发病原因及机制的研究,对预防和降低胎儿脑损伤的发生至关重要。随着胎儿治疗的开展,复杂性单绒毛膜双胎导致的胎儿脑损伤备受关注,胎儿因素中复杂性双胎如双胎输血综合征(TTTS)、双胎之一死亡(SIUD)、选择性胎儿生长受限(s IUGR)等,其脑损伤的发生率明显高于非复杂性双胎。     

胎儿生长受限的病因研究进展

胎儿生长受限（FGR）又称宫内生长受限（IUGR）,是指胎儿在母体、胎儿自身以及环境因素影响下未达到其生长潜能,是产科常见疾病之一,也是我国围生儿死亡的主要原因之一。FGR可以引起多种围生儿不良妊娠结局,包括胎儿窘迫、低出生体质量儿、早产等,且与多种远期或成年疾病相关,如代谢综合征、心血管疾病。预防FGR的发生对于提高人口素质有重要意义,但引起FGR的因素众多,主要包括母体因素、胎儿因素及胎盘、脐带因素,各种因素并不只以单一的形式存在,全面了解其发生因素有助于预防该疾病的发生。对FGR的病因进行综述,以期为该疾病的预防提供理论基础。。     

单绒毛膜双胎选择性胎儿生长受限的病因学研究进展

选择性胎儿生长受限(sFGR)是单绒毛膜(MC)双胎妊娠的一种特殊并发症,具有较高的围产儿病率及死亡率。其病因至今尚未明确,除双胎胎盘份额不均、脐带插入位置异常等胎盘大体结构因素外,近年来研究发现sFGR的发生发展也与DNA甲基化、印记基因等表观遗传因素及血管生成因子、氧化应激等分子生物学因素有关。本文就sFGR的病因学相关研究进展作一简要综述。     

胎儿生长受限的病因和治疗

胎儿生长受限是产科重要并发症之一,是围产儿死亡和发病的重要原因.该病的病因包括母体、胎儿、胎盘三方面的因素.B超可用于早期诊断.补充营养素,卧床休息,氧疗以及应用阿斯匹林、舒喘宁等药物可能会增加胎儿体重.孕晚期及时处理可以改善胎儿预后.     

以生物测量图表评估不同绒毛膜双胎的生长模式

为研究单绒毛膜双胎和双绒毛膜双胎以及两种绒毛膜类型双胎中一致双胎和不一致双胎的不同生长模式,选择1993～1997年间155对双胎进行研究,选择标准如下:妊娠9～11周时停经日期与头臀长度相符;绒毛膜类型于早孕时用超声发现两个胎儿在一个妊娠囊内或产后胎盘的组织学检查发现血管吻合在胎盘的羊膜表面定义为单绒毛膜双胎。早孕时超声发现两个独立的妊娠囊或双胎性别不同定义为双绒毛膜双胎;无母体合并症,未服影响胎儿生长的药物。     

胎儿生长受限分类与管理研究进展

胎儿的生长受母体疾病、胎盘功能、胎儿遗传等多因素影响。胎儿生长受限(FGR)是临床产科极具挑战的问题,围产期患病和死亡率较高,远期预后不良。回顾国内外FGR最新研究进展、指南及专家共识,重点针对非遗传因素FGR的定义分类、超声监测和分娩时机进行综述,为FGR的临床管理提供一定的科学依据,以期改善FGR胎儿的近、远期结局。     

双胎栓塞综合征

双胎栓塞综合征 (ｔｗｉｎｅｍｂｏｌｉｚａｔｉｏｎｓｙｎｄｒｏｍｅ ,ＴＥＳ)是宫内共用同一个胎盘的双胎存在胎儿间输血伴一胎宫内死亡时少见的并发症[1] 。 196 1年Ｂｅｎｉｒｓｃｈｋｅ[2 ] 首次发现 ,1989年被正式定义。宫内一胎死亡占全部双胎妊娠的 0 5 %～6 8% [3] 。引起宫内胎儿死亡的原因有 :(1)脐带因素 ;(2 )胎盘因素 ;(3)胎儿畸形 ;(4)严重的双胎间输血等[4 ,5] 。停经10周以内 ,双胎中一胎死亡的发生率约为 71% ,死亡的胎儿多数被吸收 ,对母体及另一胎儿无明显影响。当多胎妊娠在孕中期以后发生一胎死亡时 ,则对母体及存…     

脐动脉血流监测在产科的应用

脐动脉血流监测做为非侵入性的胎儿胎盘血流动力学评估方法,广泛应用于产科临床。脐动脉多普勒血流波形主要反映胎盘的血管阻力,受绒毛血管发育状况的影响。同时,胎龄、胎儿心率、胎儿呼吸和呃逆、胎动、脐带的采样位置、胎儿性别、胎盘重量及胎儿体重等也对其有一定的影响。循证医学证据推荐将脐动脉超声多普勒检测作为胎儿生长受限及双胎选择性生长受限的胎儿监测。在低危人群中,脐动脉血流监测的意义还存在很多争议。舒张末期血流缺失或反向与围产期结局显著不良相关,需注意排除胎儿先天性异常及非整倍体异常。脐动脉血流异常的产科处理取决于脐动脉多普勒检查结果异常的严重程度、基础产科并发症的严重程度以及孕周,应个体化处理。     

Monoamniotic twins: diagnosis and management

Monoamniotic twins, although uncommon, are associated with high antenatal and perinatal morbidity and mortality. The associated complications include cord entanglement, congenital anomalies, twin-twin transfusion syndrome, intrauterine growth retardation and preterm delivery. A thorough literature search using Medline and OVID was performed to look at the current diagnostic criteria for monoamniotic twins and the subsequent management. Specific criteria are employed during ultrasonography for making the diagnosis. Different opinions in the literature exist regarding the proper antepartum monitoring of monoamniotic twins, the optimal timing and the mode of delivery. Generally, it is agreed that there should be regular antepartum fetal heart trace monitoring and serial sonograms with umbilical artery Doppler flow study. Most studies advocate delivery at 32 weeks to reduce the risk of intrauterine deaths related to cord entanglement. Cesarean section is the preferred mode of delivery even though cases of successful vaginal delivery have been reported.     

Ghrelin levels in cord blood from concordant and discordant twin pairs: association with birth weight and postnatal catch-up growth

Objective.?To determine whether cord blood ghrelin levels in discordant and concordant twins predict postnatal catch-up growth.

Methods.?After obtaining parental consent, cord blood samples were collected at delivery for total ghrelin analysis. Infant weight, length and head circumference were obtained at birth, 2, 4, and 6 months of age. Data points post-discharge were obtained from the pediatrician's office or via parent contact. Pearson correlation evaluated the relationship between cord blood ghrelin levels and postnatal catch-up growth.

Results.?There was a statistically significant correlation between cord blood ghrelin levels and birth weight among concordant twins, but not among the discordant twins. Cord blood ghrelin levels did not predict postnatal growth at 6 months of age overall, but did so in the subset of monochorionic, discordant pairs.

Conclusion.?Cord blood ghrelin levels did not correlate overall with birth size or postnatal catch-up growth in concordant and discordant twin pairs, but did so in selected subsets. Further studies are needed.     

Genetic factors and fetal growth sex constitution and birthweight in twins

Fetal growth is considered a multifactorially-influenced characteristic. Genetic factors were found to play the main role in fetal growth determination, and it is the polygenic inheritance. The paper reviews the birthweights of 360 unlike-sexed two-egg twins, born at the Clinic of Gynecology and Obstetrics, Faculty of Medicine in Beograd, from January 1, 1970 through June 30, 1984. The mean birthweight differences between the male (2954.94 +/- 704.28 g) and female (2313.19 +/- 651.32 g) fetuses, amounted to 141.75 g. The difference is highly significant (P less than 0.01); variation coefficient shows that the examined groups were homogenous (VC was below 30%). The results were discussed from the genetic point of view, and particularly from the point of view of sex constitution, with special respect to the effect of Y chromosome on fetal growth. It has been known that human somatic development, body weight, bone maturation and teeth development are influenced by variety of factors. In addition to nutritional and other factors of the external environment, genetic and humoral factors are leading. The fact that fetuses with XY male constitution are heavier at birth than female fetuses with XX constitution, made us consider the correlation between genotype-phenotype, and the mentioned characteristics. This study was aimed at finding out the role of genetic factors in fetal growth, with respect to sex constitution, particularly to chromosome effect on fetal growth in unlike-sexed two-egg twins.     

Angiogenic growth factors in maternal and fetal serum in concordant and discordant twin pregnancies

Abstract

Objective: To assess soluble fms-like tyrosin kinase 1 (sFlt-1), free vascular endothelial growth factor (f-VEGF) and the f-VEGF/sFlt-1 quotient in twin pregnancies, and to determine if they are impaired in discordant twins.

Methods: Case-control study between 18 discordant and 46 concordant twin pregnancies. Angiogenic growth factors were measured in maternal serum during pregnancy and in umbilical artery and vein at birth.

Results: Discordant twins were more often conceived by assisted reproductive techniques than concordant twins. Maternal plasma f-VEGF was significantly lower in discordant twins (p?=?0.04). F-VEGF and f-VEGF/sFlt-1 in the whole sample show a significant higher level in concordant twins. When we analyzed umbilical cord angiogenic factors, the smaller twin had a lower f-VEGF/sFlt-1 quotient (p?=?0.01). We found no correlations between maternal or umbilical growth factors and placental or fetal weight. No difference was found in veno-arterial levels of angiogenic factors in each twin; however, there was a significant rise in arterial f-VEGF (p?=?0.06) in discordant twins.

Conclusion: Mothers of discordant twins have a more anti-angiogenic environment compared to those of concordant twins. We also found an anti-angiogenic environment in the small twin when we compared umbilical vein angiogenic factors against its big co-twin.     

Oxidized low-density lipoproteins in cord blood from neonates with intra-uterine growth restriction

Objective

We verified whether oxidative stress indices (oxidized low-density lipoproteins and malondialdehyde) and inflammatory biomarkers (circulating C-reactive protein, interleukin-6, tumour necrosis factor-α, serum amyloid A and soluble intercellular vascular cell adhesion molecule) are increased in the umbilical vein of placental insufficiency induced intra-uterine growth restricted neonates.

Study design

The prospective cohort study, involving 3 tertiary care centers, consists of 200 consecutively recruited pregnant women carrying twins. We chose the twin pregnancy model because both fetuses share the same maternal environment, thereby avoiding potential confounding factors when comparing oxidative stress and inflammation biomarkers. We analysed only twin pairs with one with intra-uterine growth restriction (N = 38) defined as fetal growth < 10th percentile with abnormal Doppler of the umbilical artery. Blood samples were taken at birth from the umbilical vein. Intra-pair comparisons on the biomarkers were performed using the Student paired t-test.

Results

We observed increased cord blood levels of oxidized low-density lipoproteins, (2.394 ± .412 vs 1.296 ± .204, p = .003) but not of malondialdehyde in growth restricted neonates when compared to their normal counterparts. Although indices of inflammation tended to be increased in cord blood from growth restricted newborns, the difference did not reach statistical significance.

Conclusion

In the twin model, intra-uterine growth restriction is associated with low-density lipoprotein oxidation without apparent dysregulation of inflammation biomarkers.

Condensation

Increased oxidized low-density lipoproteins are observed in growth restricted twins compared to their co-twins with normal growth at birth.     

Fetal serum levels of insulin, growth hormone and insulin-like growth factor-I in concordant and discordant twin gestations

OBJECTIVE: To examine the role of insulin, growth hormone and insulin-like growth factor (IGF)-I in concordant and discordant twin pairs. METHODS: Umbilical cord serum samples were obtained from 20 twin pairs with weight discordancy (intertwin birth weight difference > 20%) and from 20 concordant twins (intertwin birth weight difference < 20%), both groups of similar gestational age, gravidity, and parity. The serum samples were analyzed for the levels of IGF-I, growth hormone and insulin in both maternal and fetal compartments. RESULTS: Among the group of discordant twins, the normally grown twin, in all cases, had significantly higher cord serum IGF-I levels than their growth-restricted co-twin (108 +/- 73 ng/ml vs. 39 +/- 24 ng/ml; p < 0.01). There were no significant intertwin differences in the cord blood IGF-I levels in the concordant twin pairs (87 +/- 44 vs. 88 +/- 48 ng/ml; p = 0.986). Insulin and growth hormone levels did not correlate with intertwin birth weight differences. CONCLUSION: These data demonstrate that IGF-I is important in the regulation of both normal and restricted fetal growth in utero, and its action appears to be, at least in part, through an endocrine action. The precise role of growth hormone and insulin in fetal growth restriction remains uncertain.     

Fetal serum levels of insulin,growth hormone and insulin-like growth factor-I in concordant and discordant twin gestations

Objective: To examine the role of insulin, growth hormone and insulin-like growth factor (IGF)-I in concordant and discordant twin pairs. Methods: Umbilical cord serum samples were obtained from 20 twin pairs with weight discordancy (intertwin birth weight difference > 20%) and from 20 concordant twins (intertwin birth weight difference < 20%), both groups of similar gestational age, gravidity, and parity. The serum samples were analyzed for the levels of IGF-I, growth hormone and insulin in both maternal and fetal compartments. Results: Among the group of discordant twins, the normally grown twin, in all cases, had significantly higher cord serum IGF-I levels than their growth-restricted co-twin (108 &#45 73 ng/ml vs. 39 &#45 24 ng/ml; p < 0.01). There were no significant intertwin differences in the cord blood IGF-I levels in the concordant twin pairs (87 &#45 44 vs. 88 &#45 48 ng/ml; p = 0.986). Insulin and growth hormone levels did not correlate with intertwin birth weight differences. Conclusion: These data demonstrate that IGF-I is important in the regulation of both normal and restricted fetal growth in utero, and its action appears to be, at least in part, through an endocrine action. The precise role of growth hormone and insulin in fetal growth restriction remains uncertain.     

Growth curves for twins in Slovenia

Abnormalities of fetal growth are more common in twins. We introduce the growth curves for monitoring fetal growth in twin pregnancies in Slovenia. Slovenian National Perinatal Information System for the period between 2002 and 2010 was used to calculate birth weight percentiles for all live born twins for each week from 22nd to 40th week. The calculated percentiles of birth weight for all live-born twins in Slovenia served as the basis for drawing 'growth' curves. The calculated growth curves for twins will help accurately diagnose small or large twin fetuses for their gestational age in the native central European population.     

Wharton's jelly as a reservoir of peptide growth factors

This study has assessed the amounts of insulin-like growth factor I (IGF-I), fibroblast growth factor (FGF), transforming growth factor beta (TGF-beta), platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) and their binding to extracellular matrix components of Wharton's jelly. Studies were performed on the umbilical cords taken from human newborns delivered by healthy mothers. Wharton's jelly was separated and submitted to homogenisation and extraction with acetic acid and Tris-HCl buffer. The assays of growth factors were carried out with the use of ELISA commercial kits, together with SDS/polyacrylamide gel electrophoresis of tissue extracts followed by Western immunoblotting. Several growth factors, viz. acidic FGF, basic FGF, EGF, IGF-I, PDGF and TGF-beta were detected in Wharton's jelly. The amounts of these factors per gram of tissue vary from about 40 pg (EGF, PDGF) to about 200 ng (IGF-I). The amounts of peptide growth factors calculated per microgram of DNA are distinctly higher in Wharton's jelly in comparison to the umbilical cord artery. Western blot analysis demonstrated that almost the entire amount of these factors is bound to high molecular weight components. Since the number of cells in Wharton's jelly is very low and the amounts of extracellular matrix components are very high, it is concluded that the cells are strongly stimulated by peptide growth factors to produce large amounts of collagen and glycosaminoglycans.     

Placental characteristics in monochorionic twins with selective intrauterine growth restriction assessed by gradient angiography and three-dimensional reconstruction

Objective: To investigate the placental characteristics in selective intrauterine growth restriction (sIUGR) using gradient angiography and three-dimensional (3D) reconstruction from computed tomography (CT) scan data.

Methods: This study included 23 sIUGR cases and 16 monochorionic twin-pregnancies without sIUGR. We injected nonionic iodinated contrast agents into the umbilical arteries and veins. Placental characteristics were analyzed after CT scanning and 3D reconstruction.

Results: 73.9% of smaller twins in sIUGR cases had marginal or velamentous cord insertions and less placental sharing. The terminal branch of the arterial tree was scored III–IV in smaller sIUGR twins, while it was scored V–VII in normal monochorionic twins and larger sIUGR twins. Arterio-arterial (A-A) anastomoses presented in all monochorionic placentas. Veno-venous (V-V) anastomoses present in 83.3% (5/6) of Type III sIUGR cases, which was higher than observed in Type I–II cases. The mean diameters of A-A and V-V anastomoses were larger in Type III sIUGR cases.

Conclusions: Gradient angiography and 3D placental models displayed different placental angioarchitectures and voluminal placental sharing among three types of sIUGR cases. Placental dysplasia in the smaller twin may cause abnormal cord insertion and unequal placental sharing. The inter-twin anatomoses influence the umbilical cord artery (UA) Doppler and natural pathogenesis of sIUGR.