正常单胎及双胎妊娠妇女子宫动脉血流变化的比较

目的探讨正常单胎和双胎妊娠妇女子宫动脉血流搏动指数（ＰＩ）在孕期中的变化,并研究子宫动脉血流ＰＩ与胎盘位置的关系。方法采用Ｄｏｐｐｌｅｒ超声诊断仪,对９９例正常单胎妊娠和２４例正常双胎妊娠妇女的子宫动脉血流ＰＩ进行了检测,并同时探测胎盘的位置。结果单胎妊娠妇女的子宫动脉血流ＰＩ无论是胎盘侧或是对侧,均随孕周增加至分娩呈逐渐下降,孕２９周时子宫动脉血流ＰＩ平均值０．７８±０．１３。但双胎妊娠妇女的子宫动脉血流ＰＩ值随孕周逐渐下降至孕２７周后,则维持在一平台水平。孕２９周时子宫动脉血流ＰＩ平均值０．６７±０．１１,无论是单胎妊娠还是双胎妊娠,胎盘侧子宫动脉血流ＰＩ值均较对侧为低。结论单胎或双胎妊娠胎盘侧子宫动脉均较对侧血流丰富;且双胎妊娠时子宫动脉血流阻力较单胎为低。     

Maternal plasma adenosine and endothelin-1 levels in twin gestation complicated by preeclampsia

The aim of this study was to evaluate the relationship between the vascular resistance in uterine arteries and the maternal release of adenosine and endothelin-1 in twin gestations with and without preeclampsia. Uterine artery Doppler velocimetry and maternal arterial blood sampling were performed in 14 women with normal singleton gestation, nine women with singleton gestation with preeclampsia, eight women with dichorionic twin gestation without preeclampsia and six women with dichorionic twin gestation with preeclampsia at 28–34 weeks’ gestation. In normal singleton gestations, the average maternal uterine arteries pulsatility index (PI), plasma adenosine and endothelin-1 levels were 0.64±0.07, 0.34±0.11 μmol/l and 1.29±0.31 pg/ml, respectively. In preeclamptic singleton gestations, increased vascular resistance in the uterine arteries (PI: 0.85±0.14, P<0.05) and the elevation of maternal arterial plasma adenosine (0.48±0.14 μmol/l, P<0.05) and endothelin-1 levels (1.91±0.55 pg/ml, P<0.05) were observed. In the normal twin gestation group, the average maternal vascular resistance of the uterine arteries (PI: 0.55±0.09) was lower than that in the normal singleton gestation group, while the average plasma adenosine levels (0.47±0.12 μmol/l) were higher than that in normal singleton gestation. On the other hand, significant increased plasma endothelin-1 concentrations (1.87±0.42 pg/ml) were observed in the preeclamptic twin gestation groups without changes in plasma adenosine levels or vascular resistance of uterine arteries. Our results indicate the presence of different mechanisms for the pathogenesis of preeclampsia between twin and singleton gestations. Received: 5 October 2001 / Accepted: 3 December 2001 Correspondence to S. Suzuki     

行IVF/ICSI各年龄段妇女早期单、双胎妊娠丢失的回顾性研究

目的:分析行IVF/ICSI的各年龄段妊娠妇女早期单、双胎妊娠胚胎丢失的影响因素。方法:回顾性分析行IVF/ICSI治疗,授精后第2日或第3日移植2~3个胚胎后单、双胎妊娠周期中早期妊娠囊丢失情况。结果:共收集到1 674个IVF/ICSI周期,孕6周单胚胎着床1 077例,双胚胎着床597例。孕12周时单胎和双胎的继续妊娠数分别为901例(83.66%)和548例(91.79%)(P<0.001)。双胎妊娠中,21例(3.52%)自然减胎成单胎,28例(4.69%)自然流产。单胎和双胎妊娠中,每个着床妊娠囊的丢失率分别为16.34%(176/1 077),6.45%(741/1 194)(P<0.001)。妊娠妇女早期妊娠囊丢失率单胎者高于同年龄段双胎妊娠者,26~37岁各年龄段妇女单胎与双胎妊娠丢失率间差异均有统计学意义(P<0.05),≥38岁妇女双胎妊娠丢失率显著增加。单胎妊娠组Gn每日用量显著高于双胎妊娠组(P<0.05),而受精率及优质胚胎率单胎妊娠组显著低于双胎妊娠组(P<0.001),Gn每日用量、受精率及优质胚胎率在妊娠丢失组和继续妊娠组间无统计学差异(P>0.05)。结论:双胎妊娠早期能获得更好的继续妊娠机会,随年龄增加尤其是≥38岁妇女,妊娠丢失显著上升。胚胎形态学质量好则有助于双胚胎着床,但是对继续妊娠没有直接明显的影响。     

Correlation between depression, anxiety, and nausea and vomiting during pregnancy in an in vitro fertilization population: a pilot study

The study objective is to compare the prevalence of nausea and vomiting of pregnancy (NVP) in singleton and twin gestations conceived via in vitro fertilization (IVF), and to analyze the impact of associated psychological factors. A cohort study on 45 singleton and 12 twin gestations was conducted at an academic practice. Three validated questionnaires assessing anxiety; depression; and NVP at baseline, 10-12 weeks, and 20-22 weeks gestation were used. The prevalence of NVP was compared between twins and singletons and its association with depression and anxiety was determined. Significantly more subjects with twin pregnancies reported NVP at 10-12 weeks of gestation. NVP was not associated with baseline depression or anxiety scores. There were no differences in depression scores between the groups at any time. A trend toward higher anxiety scores among twin gestations at 10-12 weeks was significant at 20-22 weeks. Within the twin group, anxiety scores remained stable, but scores for singletons decreased significantly from 10-12 weeks to 20-22 weeks. NVP is more common in the first trimester in twins compared with singletons following IVF. In IVF pregnancies, anxiety scores, but not depression scores, are higher in women with twin gestations. Women undergoing infertility treatment should be counseled accordingly when discussing the risks associated with multiple gestations.     

Spontaneous fetal reduction in multiple gestations assessed by transvaginal ultrasound.

OBJECTIVE: To assess the occurrence of disappearance of one or more of the fetuses in pregnancies which start as multiple gestation. DESIGN: Observational study. SETTING: Infertility section, Rambam Hospital, Haifa. SUBJECTS: 88 women with multiple gestations, established after ovulation induction (54 twin, 26 triplet, five quadruplet, and three quintuplet) and diagnosed by transvaginal ultrasound at 5-6 weeks, in all of whom absorption of at least one gestation sac was detected at follow-up ultrasound scan. INTERVENTIONS: Follow-up by serial transvaginal and later abdominal ultrasound scan throughout pregnancy. RESULTS: Of the 54 twin gestations, 51 ended in the birth of a singleton and three in miscarriage. Of the 26 pregnancies starting as triplets, 12 ended in singleton births, 12 in twins and two miscarried. The five quadruplet gestations resulted in one singleton birth, one set of twins, two triplets, and one ended in late miscarriage. Of the three quintuplet pregnancies, two resulted in the birth of triplets, one of them after spontaneous, the other after iatrogenic fetal reduction. In the third quintuplet pregnancy, one fetus vanished spontaneously and another was subject to iatrogenic reduction, two fetuses survived and were liveborn. Of the 221 fetuses identified 107 (48%) vanished spontaneously. CONCLUSION: Iatrogenic fetal reduction should be delayed until 12 weeks gestation in quadruplet or higher multiple gestations, but is probably not indicated in twin and triplet gestations.     

Risk of fetal loss in twin pregnancies undergoing second trimester amniocentesis(1)

OBJECTIVE: To assess the rate of fetal loss among bichorionic twin gestations undergoing genetic amniocentesis compared with singletons undergoing the procedure and untested twins. METHODS: In a retrospective cohort study, three groups were compared: 476 women with twins undergoing amniocentesis, 489 women with singleton gestations undergoing amniocentesis, and 477 women with twins presenting at a similar gestational age for ultrasound studies only. All subjects were scanned at 17-18 weeks' gestation and again approximately 4 weeks after the procedure or first ultrasound scan. Excluded were twin pregnancies after fetal reduction or chorionic villus sampling, fetuses with structural anomalies, and cases in which one fetus had died at the time of examination or after fetal reduction. RESULTS: Thirteen twin gestations in the tested group (2.73%) aborted spontaneously up to 4 weeks after the procedure compared with three twin controls (0.63%, P =.01) and three post-procedure singleton controls (0.6%, P =.01). An abnormal karyotype was discovered in 15 tested twin pregnancies (3%) and in six tested singletons (1.23%). All affected twin pairs were discordant for the chromosomal anomaly. CONCLUSION: The risk of early fetal loss in twins undergoing amniocentesis appears to be higher than that of exposed singletons or unexposed twins.     

Clinical management of the short cervix

Cervical cerclage is associated with prolongation of gestation in singleton pregnancies with prior spontaneous preterm delivery and a short cervix on vaginal ultrasonography in the mid-trimester. Ultrasound screening of cervical length is not indicated in low-risk singleton pregnancies and in women with multiple gestations. 17α-Hydroxyprogesterone does not prevent preterm delivery in twin gestations with a short cervix. Cervical cerclage may cause detrimental effects in twin gestations. Vaginal pessary for the prevention of preterm birth in women with a short cervix is currently under active investigation.     

Symphysis-fundus height and weight gain pattern in Japanese women with twin pregnancies

OBJECTIVE: To determine the normogram for symphysis-fundus height and weight gain pattern in Japanese women with twin pregnancies and to examine whether fundus height and weight gain pattern are altered in women who give birth to twin infants complicated by fetal growth restriction (FGR). STUDY DESIGN: A retrospective review of the medical records of 186 twin gestations that had been followed at our institution together with 229 singleton pregnancies as a control. We examined maternal symphysis-fundus height, body weight gain and increase in body mass index (BMI) according to gestational age and compared them between women with and without FGR. RESULTS: As compared to women with singleton pregnancies, those with twins exhibited larger fundus height, larger weight gain and larger increase in BMI, all of which were observed from as early as 16-18 weeks of gestation until delivery. Mothers of twins with at least one FGR infant showed smaller fundus height, smaller weight gain and smaller increase in BMI as compared to those without. CONCLUSION: We constructed the normogram for symphysis-fundus height and weight gain pattern in Japanese twin gestations and determined the characteristic change in these parameters in FGR in women with twins. These results may be of use in identifying mothers of twins with FGR.     

Infertility patients and their partners: differences in the desire for twin gestations

OBJECTIVE: To explore how the individuals within an infertile couple differ from one another in their attitudes toward the conception of twin gestations. METHODS: From November 1999 through February 2000, consecutive couples undergoing treatment at a university-based infertility clinic were invited to participate in a face-to-face interview that ascertained their individual desires for singleton and twin gestations and their perception of the risks associated with these pregnancies. RESULTS: Of the 94 couples approached, 90 (96%) agreed to participate in the study. Patients estimated the incidence of prematurity, low birth weight, preeclampsia, and postpartum depression in twin gestations to be significantly greater than their partners did (27% versus 17%, 26% versus 17%, 22% versus 16%, and 21% versus 16%, respectively). Despite these higher estimates, the desire for a twin gestation was similar. In 19 couples (21%), the patient and partner did not agree whether a singleton or twin pregnancy was the most preferred outcome. No predictive factor for this discordance could be identified. CONCLUSION: Women undergoing infertility treatment are less risk averse than their partners. Additionally, a sizeable portion of couples do not align in their preference for a twin gestation. These differences should be recognized and addressed during the preconceptional period.     

Differences in TDx fetal lung maturity assay values between twin and singleton gestations

OBJECTIVE: The purpose of this study was to quantify differences in indexes of pulmonary maturity between singleton and twin gestations by means of the TDx fetal lung maturity assay.Study Design: We identified records of a total of 830 singleton and twin pregnancies not complicated by diabetes and delivered between 28 and 37 weeks' gestation from December 1994 through August 1995. Among these, 170 (20%) had TDx fetal lung maturity measurements performed within 72 hours of delivery. Linear regression was used to assess differences in TDx fetal lung maturity assay values between singleton gestations (n = 143 gestations) and twin gestations (n = 27 gestations) while controlling for potential confounding factors. RESULTS: Twin gestations were no more likely than singleton gestations to undergo TDx fetal lung maturity screening (odds ratio, 1.3; 95% confidence interval, 0.8-2.2). Pregnancy complications and corticosteroid treatment were similar in the two groups. After 31 weeks' gestation the twin gestations had significantly higher TDx fetal lung maturity values. Linear regression with controls for gestational age indicated that twin gestations on average had a TDx fetal lung maturity value that was 22.0 mg/g (95% confidence interval, 9.8-34.6 mg/g) higher than that of gestational age-matched singleton gestations. CONCLUSION: Beyond 31 weeks' gestation twin pregnancies appeared to have a TDx fetal lung maturity value that was 22 mg/g higher than that of singleton pregnancies. If the underlying incidences of respiratory distress syndrome are similar between twin and singleton gestations, then the potential exists for false-positive prediction of adequate lung maturity values among twin gestations.     

Twin vs. singleton pregnancy. Clinical characteristics and latency periods in preterm premature rupture of membranes.

OBJECTIVE: To compare the clinical characteristics and latency periods (latencies) of preterm premature rupture of the membranes (PPROM) in twin vs. singleton pregnancy. STUDY DESIGN: Between January 1986 and December 1996, data on all women with singleton and twin gestations complicated by PPROM were reviewed. Perinatal morbidity, mortality and latencies between singleton and twin pregnancies were compared. A further division according to PPROM at < 30 and > or = 30 weeks' gestation was made in both groups. Their latencies were compared. RESULTS: A total of 131 singleton and 48 twin pregnancies with PPROM between 20 and 36 weeks' gestation were included in this series. Regardless of the gestational age at PPROM, the mean latencies of singleton and twin pregnancies were statistically similar (4.4 +/- 3.3 vs. 3.4 +/- 2.9 days, nonsignificant). When PPROM occurred at > or = 30 weeks, the latency of twin pregnancies was shorter than that of singleton pregnancies (2.5 +/- 1.9 vs. 3.7 +/- 2.6 days, P < .05). In both groups, the latencies of PPROM at < 30 weeks were longer than that at > or = 30 weeks (singleton, 5.6 +/- 4.0 vs. 3.7 +/- 2.6 days, P < .005; twin, 4.8 +/- 3.5 vs. 2.5 +/- 1.9 days, P < .05). We also observed a higher percentage of deliveries within the initial 48 hours in twin pregnancies: 50% of women delivered within 48 hours after PPROM and 91.7% within 7 days. In contrast, 26.7% and 85.5% of singleton pregnancies with PPROM were delivered within 48 hours and 7 days, respectively. Perinatal and neonatal outcomes in both groups were similar. CONCLUSION: This investigation provides the basis for patient counseling and management in twin pregnancies with PPROM. In general, singleton and twin pregnancies with PPROM had similar latencies. Latency in PPROM at < 30 was longer than that of PPROM at > or = 30 weeks' gestation in both singleton and twin pregnancies. When PPROM occurred at < 30 weeks' gestation, both groups appeared to have similar latencies. In pregnancies with PPROM at > or = 30 weeks' gestation, latency in twins was shorter than in singleton pregnancies. In twin pregnancies with PPROM after 30 weeks' gestation, prompt steroid administration for fetal lung maturity should be considered.     

Influence of parity on fetal mortality in prolonged pregnancy

OBJECTIVE: In England an estimated 50,000 inductions of labour at or beyond 41 weeks' gestation are conducted each year. However, the published evidence on the effect of parity on stillbirth in prolonged pregnancy is limited, and has produced conflicting data. The aim of this study is to evaluate the influence of parity on fetal mortality in prolonged pregnancies. STUDY DESIGN: Retrospective analysis of 145,695 singleton births with known parity and no malformation noted at birth to residents in the former North-East Thames Region, UK. The parity and gestation specific stillbirth risks and relative risks per 1000 ongoing pregnancies were calculated in relation to parity between 37 and 45 weeks. RESULTS: Before 41 weeks the stillbirth risk rose gradually but did not differ by parity. By 41 weeks there was a substantial increase in the stillbirth risk in nulliparous women but not in parous women. The pattern of rise is such that the stillbirth risk is 2.9 times higher (95% CI 1.06-8.19) in nulliparous women at >42 weeks' gestation. CONCLUSION: Being parous appears to have a protective effect on fetal mortality in prolonged pregnancy. These findings question the need for routine induction of labour at 41 weeks in parous women.     

Hypertensive disorders in twin versus singleton gestations. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

OBJECTIVE: This study was undertaken to compare rates and severity of gestational hypertension and preeclampsia, as well as perinatal outcomes when these complications develop, between women with twin gestations and those with singleton gestations. STUDY DESIGN: This was a secondary analysis of prospective data from women with twin (n = 684) and singleton (n = 2946) gestations enrolled in two separate multicenter trials of low-dose aspirin for prevention of preeclampsia. End points were rates of gestational hypertension, rates of preeclampsia, and perinatal outcomes among women with hypertensive disorders. RESULTS: Women with twin gestations had higher rates of gestational hypertension (relative risk, 2.04; 95% confidence interval, 1.60-2.59) and preeclampsia (relative risk, 2. 62; 95% confidence interval, 2.03-3.38). In addition, women with gestational hypertension during twin gestations had higher rates of preterm delivery at both <37 weeks' gestation (51.1% vs 5.9%; P <. 0001) and <35 weeks' gestation (18.2% vs 1.6%; P <.0001) and also had higher rates of small-for-gestational-age infants (14.8% vs 7. 0%; P =.04). Moreover, when outcomes associated with preeclampsia were compared, women with twin gestations had significantly higher rates of preterm delivery at <37 weeks' gestation (66.7% vs 19.6%; P <.0001), preterm delivery at <35 weeks' gestation (34.5% vs 6.3%; P <.0001), and abruptio placentae (4.7% vs 0.7%; P =.07). In contrast, among women with twin pregnancies, those who remained normotensive had more adverse neonatal outcomes than did those in whom hypertensive complications developed. CONCLUSIONS: Rates for both gestational hypertension and preeclampsia are significantly higher among women with twin gestations than among those with singleton gestations. Moreover, women with twin pregnancies and hypertensive complications have higher rates of adverse neonatal outcomes than do those with singleton pregnancies.     

Antithrombin III activity and platelet count are more likely to decrease in twin pregnancies than in singleton pregnancies

BACKGROUND: It is not known whether antithrombin III activity and platelet count are more likely to decrease in women with twin pregnancies than singleton pregnancies. METHODS: We enrolled 56 consecutive women with twin pregnancies and 692 consecutive women with singleton pregnancies. Antithrombin III activity and platelet count were determined at 26-31 weeks and again at 32-40 weeks of gestation. Thrombin-antithrombin complex, and plasmin-alpha2 plasmin inhibitor complex were measured simultaneously in some women. RESULTS: In twin pregnancies, both antithrombin III activity (111 +/- 8.2%) and platelet count (244 +/- 60 x 109/l) at 28.6 +/- 1.0 weeks decreased over time to 91 +/- 12% and 205 +/- 59 x 109/l, respectively, at 35.2 +/- 1.2 weeks; these decreases were significantly greater than in singleton pregnancies. However, a small number of women with singleton pregnancies had a significant decrease in antithrombin III activity in the absence of preeclampsia. The serum thrombin-antithrombin complex was significantly higher in twin pregnancies than in singleton pregnancies (9.7 +/- 4.2 ng/ml vs. 6.7 +/- 4.4 ng/ml, respectively, p < 0.01), and this increase correlated significantly with the decrease in antithrombin III activity in twin pregnancies (r = -0.459, p < 0.001). CONCLUSIONS: Antithrombin III activity and platelet count show a greater decrease in twin than in singleton pregnancies, perhaps due to a greater increase in thrombin generation.     

Accuracy of fetal fibronectin to predict preterm birth in twin gestations with symptoms of labor

OBJECTIVE: To investigate accuracy of fetal fibronectin testing to predict preterm birth in twin gestations with symptoms of preterm labor. METHODS: We reviewed charts of all patients with twin gestations who underwent fetal fibronectin testing and presented with complaints of preterm labor between January 1, 2000, and June 30, 2004. We also reviewed the charts of all singleton gestations with similar complaints that had fetal fibronectin testing between January 1, 2000, and December 31, 2001. All samples were processed using a rapid fetal fibronectin detection system. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of fetal fibronectin testing in singleton and twin gestations in predicting delivery within 14 days of testing. RESULTS: Four hundred twenty-nine singletons and 87 twins met the inclusion criteria. The birth rate before 34 weeks of gestation for singletons was 3.5% compared with the rate of twin pregnancies of 28.7%. Fetal fibronectin predicted delivery within 14 days of testing with a sensitivity, specificity, and positive and negative predictive values in singleton gestations of 82%, 90%, 17%, and 99%, respectively. In twin gestations, fetal fibronectin predicted delivery within 14 days of testing with a sensitivity, specificity, and positive and negative predictive values of 71%, 74%, 19%, and 97%, respectively. CONCLUSION: As noted in singleton pregnancies, fetal fibronectin testing in twins has a high negative predictive value. Fetal fibronectin evaluation may be a useful tool in screening twins with symptoms of preterm labor, because a negative result places these women at a low risk for delivering within 2 weeks of testing.     

Fetal urine output in hydramnios

Fetal urine output was evaluated in 12 pregnancies complicated by hydramnios. Six of these pregnancies were twin gestations with markedly elevated fetal urine output of the hyperperfused fetus. All six fetuses had urine output greater than the 95th percentile for their gestational age. These six patients were evaluated prior to and during the 29th week of pregnancy. Three singleton gestations had upper gastrointestinal obstruction and normal fetal urine output of 18.7, 18.0, and 12.3 mL/hour at 35, 35, and 31 weeks' gestation, respectively. Markedly elevated fetal urine output of 18 mL/hour (tenth to 95th percentile at 26 weeks, 4-7 mL/hour) was present in one fetus that was subsequently found to have diabetes insipidus. The remaining two singleton pregnancies with idiopathic hydramnios had upper limits of normal fetal urine output of 10 and 13 mL/hour at 31 and 32 weeks, respectively. It appears that hydramnios may be the result of polyuria of the hyperperfused twin in cases of twin-twin transfusion or diabetes insipidus. In upper gastrointestinal obstruction or idiopathic hydramnios, increased fetal urination does not appear to be present.     

Pregnancy outcome of early multifetal pregnancy reduction: triplets to twins versus triplets to singletons

Multifetal pregnancy reduction (MPR) of triplets to twins results in improved pregnancy outcomes compared with triplet gestations managed expectantly. Perinatal outcomes of early transvaginal MPR from triplets to twins were compared with reduction from triplets to singletons. Seventy-four trichorionic triplet pregnancies that underwent early transvaginal MPR at 6–8 weeks gestation were included. Cases were divided into two groups according to the initial procedure: reduction to twin (n = 55) or to singleton (n = 19) gestations. Infants from triplet pregnancies reduced to twins were delivered earlier (36.6 versus 37.9 weeks; P = 0.04) and had lower mean birth weights (2364 g versus 2748 g; P = 0.02) compared with those from triplets reduced to singleton gestations. The rates of pregnancy loss before 24 weeks (3.6% versus 5.3%), as well as of preterm delivery before 32 and 34 weeks of gestation (0% versus 5.3% and 7.3% versus 5.3%, respectively) were similar between the twin and singleton pregnancies. No significant difference was found in the prevalence of gestational diabetes (15.1% versus 5.6%) or gestational hypertension (24.5% versus 16.7%) between the groups. Selective reduction of triplet pregnancies to singleton rather than twin gestations is associated with improved outcomes.     

Monoamnotic twin pregnancy. Multicenter study

OBJECTIVE: The purpose of this study was to evaluate of perinatal mortality and morbidity of monoamniotic twins. STUDY DESIGN: This was a multicenter retrospective analysis of 26 monoamniotic twin gestations identified between 1985 and 2004 in a 3 perinatal departments. Of these 26 pregnancies, 11 women were admitted electively for inpatient fetal monitoring. Overall mortality rates, the risk of intrauterine fetal death and neonatal mortality and morbidity, pregnancy complications and fetal anomalies were calculated. RESULTS: Monoamniotic twin pregnancies were diagnosed reliably prenatally by ultrasound in 22 women and at delivery in 4 cases. Of the 26 gestations, spontaneous fetal losses before 22 weeks of gestation were 4 cases. The overall loss rate and the perinatal mortality rate were 52% and 19.4%, respectively. Twenty-two women had both twins alive at 24 weeks of gestation; 11 women were admitted electively for inpatient fetal monitoring at 26-27 week of gestation. In this group there were 2 neonatal deaths. No intrauterine fetal death occurred in any hospitalized patient. In our series there were 100% incidence of prematurity, 38,5% of umbilical cord entaglement, 23% of TTTS, 3.6% of TRAP and 9.6% fetal congenital anomalies. CONCLUSION: Monoamniotic twins are at extremly risk of pregnancy complications and fetal loss. These pregnancies can be diagnosed reliably by ultrasound in most cases. Electively admitted women for inpatient fetal monitoring could be improved neonatal survival and decreased perinatal morbidity.     

Coagulation-fibrinolysis is more enhanced in twin than in singleton pregnancies

AIMS: To examine whether coagulation-fibrinolysis in late pregnancy in women with twin pregnancies is more pronounced than in women with singleton pregnancies. PATIENTS AND METHODS: The plasma levels of D-dimer, fibrinogen/fibrin degradation products (FDP), and fibrinogen, the platelet count, and the antithrombin activity were assessed from 3 weeks before delivery until postpartum day 7 in 48 women (24 singleton and 24 twin pregnancies) without preeclampsia who underwent cesarean sections. RESULTS: Women with singleton or twin pregnancies gave birth at 37.3+/-1.2 weeks or 35.2+/-1.4 weeks, respectively. Compared with singleton mothers, prenatal D-dimer and FDP levels were consistently and significantly higher among women with twin pregnancies. A significantly larger proportion of twin mothers exhibited prenatal levels of D-dimer >5.0 microg/mL, FDP >10.0 microg/mL, fibrinogen <420 mg/mL and antithrombin activity <70%. In addition, prenatal antithrombin activity in plasma was significantly lower. CONCLUSIONS: Coagulation-fibrinolysis is more enhanced in women with twin gestation than in women with singleton gestation.     

正常妊娠和妊娠期高血压疾病孕妇子宫动脉及其胎儿脐动脉血流动态变化规律的多中心研究

目的 探讨正常妊娠妇女和妊娠期高血压疾病(HDP)孕妇妊娠早、中、晚期子宫动脉及其胎儿脐动脉血流动态变化的规律.方法 选择2005年4月-2006年7月在四川大学华西第二医院、南京医科大学第一附属医院、首都医科大学附属北京妇产医院、华中科技大学同济医学院附属协和医院和上海交通大学医学院附属仁济医院,行产前检查的正常单胎孕妇1098例,平均年龄(28.3±3.3)岁.在妊娠早期(10～14周)、妊娠中期(20～26周)、妊娠晚期(30～36周)采用彩色多普勒超声(彩超)检测孕妇子宫动脉及其胎儿脐动脉的搏动指数(PI)、阻力指数(RI)和脐动脉收缩压最大血流速度(S)与舒张末期最大血流速度(D)比值(S/D).在孕期发生HDP的孕妇为HDP组,未发生HDP的孕妇为正常妊娠组.结果 (1)HDP发生率:1098例孕妇中,正常妊娠分娩者1054例(正常妊娠组),发生HDP44例(HDP组,其中妊娠期高血压20例,轻度子痫前期15例,重度子痫前期9例),发生率为4.01%(44/1098).(2)子宫动脉血流动态变化:正常妊娠组妊娠早、中、晚期孕妇子宫动脉RI分别为0.64、0.57及0.50,PI分别为1.24、0.98及0.80,S/D分别为3.26、2.58及2.20,3项指标随妊娠进展而逐渐降低,妊娠早、中、晚期分别比较,差异均有统计学意义(P<0.01).HDP组妊娠早、中、晚期孕妇子宫动脉RI分别为0.55、0.67及0.64,PI分别为1.22、1.36及1.20,S/D分别为3.18、3.41及3.05,3项指标中孕中期最高,妊娠早、中、晚期分别比较,差异均有统计学意义(P<0.01).HDP组孕妇妊娠中、晚期子宫动脉RI、PI及S/D均高于正常妊娠组,两组比较,差异有统计学意义(P<0.01).(3)胎儿脐动脉血流动态变化:正常妊娠组妊娠中、晚期胎儿脐动脉RI分别为0.71及0.58,PI分别为1. 16及0.87,S/D分别为3.58及2.48,3项指标随妊娠进展而逐渐降低,妊娠中期与晚期比较,差异有统计学意义(P<0.01).HDP组妊娠中、晚期胎儿脐动脉RI分别为0.71及0.63,PI分别为1.20及0.95,S/D分别为3.71及2.69,3项指标随妊娠进展虽有逐渐降低趋势,但与正常妊娠组比较,差异无统计学意义(P>0.05).结论 随着妊娠进展,正常妊娠妇女子宫动脉的血流阻力逐渐下降,舒张末期血流增加;而HDP孕妇随妊娠进展子宫动脉的血流阻力明显升高;正常妊娠妇女和HDP孕妇随妊娠进展其胎儿脐动脉血流阻力均明显下降.