双胎妊娠一胎宫内死亡34例临床分析

目的:探讨双胎妊娠一胎宫内死亡的原因、临床处理及预后。方法:回顾性分析2005年1月至2009年12月,我院双胎妊娠一胎宫内死亡34例患者的临床资料。结果:双胎妊娠一胎宫内死亡占我院双胎妊娠的5.2%,34例中单羊膜囊双胎3例,单绒毛膜双胎23例,双绒毛膜双胎8例;及时终止妊娠23例(单羊膜囊双胎均及时终止妊娠),期待治疗11例,平均期待时间单绒毛膜双胎为4.7±5.6周,双绒毛膜双胎为8.6±1.2周;单绒毛膜双胎发现死胎时的孕周、分娩孕周及存活儿的出生体重均小于双绒毛膜双胎。除引产外的30例存活儿发生围生儿死亡6例,随访24例存活新生儿中,2例失访,22例随访中发生脑瘫(四肢瘫,语言障碍)3例,存在其他脑损害(语言或运动发育延迟)4例,余健康存活。结论:单绒毛膜双胎更易发生双胎妊娠一胎宫内死亡,绒毛膜性质和孕周是影响围生儿结局和远期预后的重要因素,存活儿无胎儿窘迫,孕妇无严重妊娠并发症及合并症情况下,期待治疗是一种有效的处理方式。     

Preeclampsia in Twin Pregnancies: Incidence and Outcome

Objectives: To confirm the increased incidence of preeclampsia in twin pregnancy and to determine the relationship to zygosity and placentation; to consider the perinatal outcome of twin pregnancies in this condition.

Methods: Retrospective study of all twin pregnancies (n = 2473) identified from the Aberdeen Maternity and Neonatal Databank to women resident in the Grampian Region of Scotland for the period 1950–1995.

Results: The increased relative risk for gestational hypertension, preeclampsia, and eclampsia in twin pregnancies compared to singleton pregnancies has been confirmed as significant both in primiparas and multiparas with little variation in rates over the time period under review. Neither the sex of the offspring nor zygosity influences the incidence of hypertensive disease, whereas preeclampsia is more common in association with monochorionic placentation.

As the birth weight was lower and placental weight greater in MzMc twins compared to either MzDc or DzDc, there was a higher placental index in such cases. No difference in the birth weights of individual twins, the difference in birth weights between the twins, placental weight, or placental index were found in relation to hypertensive disease. Gestation at delivery was earlier in normotensive twin pregnancies than in those women who developed a hypertensive problem. This leads to a higher perinatal death rate and lower survival rate for the babies in normotensive women with a twin pregnancy.

Conclusion: Although gestational hypertension, preeclampsia, and eclampsia all occur more commonly in twin pregnancy, this does not lead to significant growth retardation nor discordant fetal growth and a poor outcome for the twins. Although the incidence of preeclampsia is higher in twin pregnancies with monochorionic placentation, this does not seem to be mediated by deficiencies in placental development as assessed in this study.     

双胎之一胎儿宫内死亡51例临床分析

目的:探讨双胎之一胎儿宫内死亡(sIUFD)的原因、临床处理及母婴预后.方法:回顾性分析2009～2012年在南方医科大学附属深圳妇幼保健院住院分娩的51例sIUFD孕妇(sIUFD组)的临床资料,同时随机抽取同期51例双胎均存活者作为对照组进行病例对照分析.结果:①sIUFD组胎儿畸形、胎儿生长受限(FGR)、双胎输血综合征(TTTs)、脐带扭转、单脐动脉发生率、辅助生殖技术(ART)受孕率均明显高于对照组(P＜0.05).两组妊娠期高血压疾病、妊娠期糖尿病和妊娠期肝内胆汁淤积症发生率相比,差异无统计学意义(P＞0.05).②sIUFD组发现一胎儿死亡平均孕周为28.7±6.4周,期待孕周中位数为3.1周,四分位数间距为13.1周.单绒毛膜双胎终止妊娠平均孕周为34.6±2.2周,双绒毛膜双胎为35.9±1.9周.③两组新生儿窒息发生率比较,差异无统计学意义(P＞0.05).两组均无围生儿死亡.sIUFD组随访47例,存活儿生长发育均正常,失访4例.结论:胎儿畸形、FGR、TTTS、脐带扭转和单脐动脉是sIUFD的主要原因,母体合并症及并发症与sIUFD的关系不明显,ART对sIUFD的影响有待进一步研究.单绒毛膜双胎期待治疗至妊娠34周、双绒毛膜双胎期待治疗至37周后,以改善新生儿预后.     

双胎及三胎妊娠地中海贫血产前基因诊断研究

目的:探讨双胎妊娠和三胎妊娠地中海贫血的产前基因诊断情况。方法:对27例双胎妊娠和三胎妊娠患者进行绒毛膜穿刺或羊膜囊穿刺胎儿取样,采取裂隙聚合酶链反应以及聚合酶链反应结合反向点杂交方法进行产前基因诊断。结果:在进行α地中海贫血产前基因诊断的20例双胎妊娠及1例三胎妊娠中,共对43个胎儿进行取材,共检测出6例Bart's水肿胎,3例血红蛋白H病。在进行β地中海贫血产前基因诊断的6例双胎妊娠中,共对9个胎儿进行取材,共检测到3例中重型β地中海贫血。结论:地中海贫血的多胎妊娠孕妇产前基因诊断能较有效检出Bart's水肿胎和中重型β地中海贫血患儿,可预防重型地中海贫血患儿的出生。     

Temporary Resolution of Preeclamptic Symptoms After Intrauterine Death of One Twin

In a 34 year old woman with dichorionic twin pregnancy preeclampsia resolved after the intrauterine death of one of the HLA-identical twins and recurred with the growth of the placenta of the surviving twin later in pregnancy. This case gives indirect evidence that the clinical course of preeclampsia is a dose-dependent phenomenon in conjunction with vital placental tissue.     

妊娠中晚期双绒毛膜双胎一胎胎死宫内妊娠结局分析

目的：比较双绒毛膜双胎之一选择性减胎与自发一胎胎死宫内（single intrauterine fetal death,SIUFD）的围生期结局,并比较不同减胎孕周对围生期结局的影响,探讨选择性减胎的临床应用。方法：纳入2011年1月—2019年12月在南京大学医学院附属鼓楼医院产科终止妊娠的55例双胎之一胎死宫内或行选择性减胎术将双胎减至单胎的临床资料,根据减胎或死胎原因将其分为选择性减胎组（39例）和自发SIUFD组（16例）,回顾性分析比较其围生期结局。结果：55例患者总妊娠丢失率为9.1%（5例流产）,活产率为90.9%。选择性减胎组的减胎/死胎孕周明显低于自发SIUFD组,总体终止孕周、活产率明显高于自发SIUFD组,而剖宫产率、流产率则低于自发SIUFD组,差异均有统计学意义（P<0.05）。2组的早产率、足月产率、存活儿出生体质量、出生体质量百分位数、新生儿健康出院率、新生儿重症监护病房（neonatal intensive care unit,NICU）入住率比较,差异均无统计学意义（均P>0.05）。根据选择性减胎的孕周将选择性减胎组再分为减胎孕周≤20周组（24例）和减胎孕周>20周组（15例）,2组新生儿出生体质量百分位数比较差异无统计学意义（P>0.05）,但与减胎孕周>20周组比较,减胎孕周≤20周组的早产率低、足月产率高,存活儿出生体质量更高,差异有统计学意义（均P<0.05）。结论：双胎妊娠发生SIUFD后会对存活儿围生期结局产生不良影响,对于有减胎指征者,选择性减胎有利于提高存活儿围生期的活产率及改善新生儿结局,对多胎妊娠的围生期结局有益。     

双胎之一宫内死亡7例临床分析

目的 :探讨双胎之一宫内死亡的发生率、病因、诊断及处理方法。方法 :对本院 10年来发生的晚期双胎之一宫内死亡 7例病例进行回顾性分析。结果 :晚期妊娠双胎之一宫内死亡的发生率为 3.8% ,常见原因为脐带异常、胎儿畸形、胎盘早剥等。 7例中仅 1例孕妇并发 DIC,无孕产妇死亡 ;7例健存胎儿 6例存活分娩 ,1例因胎盘早剥而死产。结论 :妊娠晚期双胎之一宫内死亡临床上较罕见 ,故对双胎妊娠加强 B超监护及孕期保健 ,有助于早期诊断此并发症 ;本症一旦发生 ,应在严密监测的基础上 ,适当延长存活儿的胎龄 ,以期母儿达到最佳预后     

体外受精-胚胎移植术后妊娠结局回顾性分析

目的:探讨体外受精-胚胎移植术后的妊娠结局。方法:回顾性分析在本生殖医学中心行体外受精-胚胎移植术、单精子卵胞浆内注射术、冻融胚胎移植术后306个妊娠周期的结局及围产儿情况,并与自然受孕妇女进行比较。结果:在306个妊娠周期中,生化妊娠11个周期,临床妊娠295个周期,流产53个周期,宫外孕10个周期,宫内外同时妊娠5个周期。共有168例分娩,与同期在我院自然妊娠分娩的6 203例相比,多胎率(34.52％vs 0.77％)、早产率(33.33％vs 4.56％)有显著性差异(P<0.05)。助孕出生的231例新生儿与自然分娩的6 186比,低体重儿率(37.23％vs 3.30％)、新生儿死亡率(0.87％vs 0.21％)、新生儿畸形率(2.16％vs 4.24％)、死胎率(1.70％vs 0.27％)均有有显著性差异(P<0.05)。另两组在前置胎盘和产后出血方面,差异也有显著性。结论:辅助生育其并发症显著高于自然妊娠。     

Perinatal Outcome of Pregnancies After Assisted Reproduction: A Case–Control Study

Purpose: A matched case–control study of all pregnancies obtained after either IVF or ICSI was conducted to investigate the perinatal outcome. Methods: Three hundred eleven singleton and 115 twin pregnancies obtained after assisted reproduction were studied. Controls were selected from a regional register and were matched for maternal age, parity, singleton or twin pregnancy, and date of delivery. Results: No significant difference was observed for gestational age at delivery, birth weight, incidence of congenital anomalies, and incidence of perinatal mortality between ART (singleton and twin) pregnancies and spontaneous controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies (52 vs 42%; P < 0.05) and needed more neonatal intensive care (47 vs 26%; P < 0.05). Conclusions: From this case–control study it is concluded that the perinatal outcome of ART singleton pregnancies is not different from that in matched controls. ART twin pregnancies showed a higher incidence of preterm deliveries than control pregnancies and needed more neonatal intensive care.     

Maternal,Fetal, and Neonatal Outcomes of Elective Fetal Reduction Among Multiple Gestation Pregnancies: A Systematic Review

ObjectiveTo review the existing literature on fetal and maternal health outcomes following elective pregnancy reduction.Data SourcesMEDLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, and the Cochrane Controlled Trials Register.Study SelectionStudies involving women pregnant with dichorionic twins, trichorionic triplets, or quadra-chorionic quadruplets who underwent elective fetal reduction of 1 or more fetuses to reduce the risks associated with multiple gestation pregnancies.Data ExtractionThe main fetal health outcomes measured were gestational age at delivery, preterm birth, miscarriage, birth weight, and small for gestational age at delivery. The main maternal health outcomes measured were gestational diabetes, hypertensive disorders of pregnancy, and cesarean delivery.Data SynthesisOf 7678 studies identified, 24 were included (n = 425 dichorionic twin pregnancies, n = 2753 trichorionic triplet pregnancies, and n = 111 quadra-chorionic quadruplet pregnancies). Fifteen studies (62.5%) did not report maternal health outcomes, while every study reported at least 1 fetal health outcome. Fetal reduction was associated with higher gestational age at birth, lower preterm birth, higher birth weight, and lower rates of small for gestational age infants and intrauterine growth restriction. No consistent pattern was observed for miscarriage and neonatal mortality rates. Following fetal reduction, cesarean delivery rates were lower in most studies. There were no appreciable trends with respect to gestational diabetes or hypertensive disorders of pregnancy.ConclusionFetal reduction reliably optimizes gestational age at birth and neonatal birth weight. Miscarriage rates and other adverse procedural outcomes did not increase following transabdominal reduction. Further research on maternal outcomes is needed given a paucity of information in the literature.     

Twin gestation in older women: antepartum, intrapartum complications, and perinatal outcomes

Objective: The aim of this study is to present pregnancy and perinatal outcomes of twin gestations in older women and compare them with that for younger women. Study design: We conducted a retrospective cohort study of twin pregnancies in our department between 1988 and 2003. The women were classified into two groups by maternal age: women of age 35 years and older (study group) and women less than 35 years (control group). Population characteristics, complications during pregnancy and delivery, and neonatal outcomes were assessed. The Student’s t-test, χ² test, Fisher exact test, and binary logistic regression analysis were used to examine the relationship between maternal age and the different variables. Results: A total of 238 twin pregnancies were enrolled (study group, 57 women; control group, 181 women). Spontaneous conceptions were significantly higher in the control group (P<0.001), while conceptions after in vitro fertilization (IVF) were significantly higher in study group (P<0.001). Mean figures of gestational age at delivery and birth weight for the older group did not differ significantly from the younger group. Although the antepartum and intrapartum complications were more common in the study group, they were not statistically significant compared to the control group. This was also true for the perinatal outcomes. Only the very low birth weight (VLBW<1,500 g) rate was significantly higher in the study group. The number of perinatal deaths was similar on comparison by maternal age. Conclusions: Based on our study, advanced maternal age at twin gestation does not seem to affect significantly pregnancy complications and perinatal outcomes. VLBW was the only unfavorable perinatal outcome related to advanced maternal age.     

不同黄体支持方案对新鲜周期移植双胎妊娠围生期结局的比较

目的:比较阴道用黄体酮缓释凝胶和注射用黄体酮针两种黄体支持方案对卵裂期新鲜胚胎移植周期双胎妊娠围生期结局的影响。方法:回顾性分析2011年1月至2016年3月在郑州大学第三附属医院生殖医学中心行体外受精/卵细胞浆内单精子注射-胚胎移植(IVF/ICSI-ET)孕早期临床确诊双胎妊娠患者900例(共900个周期),采用电话随访和电子病历查询方法,其中双胎分娩患者共705个周期,依据移植时黄体支持方案分为注射用黄体酮针组(551个周期)和阴道用黄体酮缓释凝胶组(154个周期)。比较两组间围生期妊娠期并发症发生率及妊娠结局、新生儿结局的差异。结果:两组间流产(早期流产、晚期流产)、死胎、死产、自然减胎、行减胎术、活产率(活单胎、活双胎率)比较,差异均无统计学意义(P0.05)。阴道用黄体酮缓释凝胶组的妊娠期糖尿病发生率(8.4%)较注射用黄体酮针组(3.8%)高,差异有统计学意义(P0.05),余妊娠期并发症两组间差异无统计学意义(P0.05)。两组间新生儿畸形、出生后死亡、平均出生体质量差异无统计学意义(P0.05)。结论:阴道用黄体酮缓释凝胶黄体支持方案使用方便,患者依从性好,且可获得与注射用黄体酮针相似的双胎妊娠围生期结局。     

Trend of medically induced monozygotic twin deliveries according to age,parity, and type of assisted reproductive technique during the period 2007–2017 in Lombardy Region,Northern Italy: a population-based study

PurposeThe risk of monozygotic (MZT) twinning is increased in pregnancies after assisted reproductive technologies (ART). However, determinants remain poorly understood. To shed more light on this issue, we analyzed the estimated frequency of MZT twins from ART in Lombardy, Northern Italy, during the period 2007–2017.MethodsThis is a population-based study using regional healthcare databases of Lombardy Region. After having detected the total number of deliveries of sex-concordant and sex-discordant twins from ART, we calculated MZT rate using Weinberg’s method. Standardized ratios (SRs) and corresponding 95% confidence intervals (CI) of MZT deliveries, adjusted for maternal age, were computed according to calendar period, parity, and type of ART.ResultsOn the whole, 19,130 deliveries from ART were identified, of which 3,446 were twins. The estimated rate of MZT births among ART pregnancies was higher but decreased over time (p-value = 0.03); the SRs being 1.33 (95% CI: 1.18–1.51), 0.96 (95% CI: 0.83–1.11), and 0.92 (95% CI: 0.79–1.07) for the periods 2007–2010, 2011–2014, and 2015–2017, respectively. The SRs of MZT among women undergoing first-level techniques, conventional in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI) were 0.47 (95% CI: 0.38–0.57), 1.02 (95% CI: 0.88–1.17), and 1.43 (95% CI: 1.27–1.61) (p-value < 0.0001). The ratio of MZT births was significantly higher in women younger than 35 years (p-value < 0.0001) and slightly higher among nulliparae (p-value < 0.0001).ConclusionDespite a reduction of MZT rate from ART over the time, the risk remains higher among ART pregnancies rather than natural ones. Younger women and women undergoing ICSI showed the highest risk of all.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10815-021-02268-0.     

Neonatal mortality in second twin according to cause of death, gestational age, and mode of delivery

OBJECTIVE: The purpose of this study was to assess the risk of neonatal death in the second twin. STUDY DESIGN: We carried out a retrospective cohort study of 128,219 live born second twins in the United States for the years 1995 through 1997. The study subjects were divided into 3 groups: second twins who were delivered by cesarean delivery after vaginal delivery of the first twin (group 1), both twins delivered vaginally (group 2), and both twins delivered by cesarean delivery (group 3). RESULTS: The risk of asphyxia-related neonatal deaths was increased in groups 1 and 2; the increased risk in group 1 was stronger in term births than in preterm births. CONCLUSION: The risk of neonatal deaths, especially for term infants with asphyxia-related deaths, is increased for the second twins who are delivered by cesarean delivery after vaginal delivery of the first twins.     

Maternal Hypothermia and Fetal Bradycardia Secondary to Infection: A Case Report and Literature Review

A 31-year-old woman developed hypothermia secondary to a right pyelonephritis at 34 weeks of pregnancy. Her temperature dropped to 35.1°C. At the same time, there was a sustained fetal bradycardia of 90 to 95 beats per minute. The management of maternal sepsis complicated by hypothermia and fetal bradycardia is discussed.     

Guideline No. 440: Management of Monochorionic Twin Pregnancies

ObjectiveThis guideline reviews the evidence-based management of normal and complicated monochorionic twin pregnancies.Target PopulationWomen with monochorionic twin or higher order multiple pregnancies.Benefits, Harms, and CostsImplementation of these recommendations should improve the management of both complicated and uncomplicated monochorionic (and higher order multiple) twin pregnancies. They will help users monitor monochorionic twin pregnancies appropriately and identify and manage monochorionic twin complications optimally in a timely manner, thereby reducing perinatal morbidity and mortality.These recommendations entail more frequent ultrasound monitoring of monochorionic twins compared to dichorionic twins.EvidencePublished literature was retrieved through searches of PubMed and the Cochrane Library using appropriate MeSH headings (Twins, Monozygotic; Ultrasonography, Prenatal; Placenta; Fetofetal Transfusion; Fetal Death; Fetal Growth Retardation). Results were restricted to systematic reviews, randomized controlled clinical trials, and observational studies. There were no date limits, but results were limited to English or French language materials.Validation MethodsThe content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).Intended AudienceMaternal-fetal medicine specialists, obstetricians, radiologists, sonographers, family physicians, nurses, midwives, residents, and other health care providers who care for women with monochorionic twin or higher order multiple pregnancies.Tweetable AbstractCanadian (SOGC) guidelines for the diagnosis, ultrasound surveillance and management of monochorionic twin pregnancy complications, including TTTS, TAPS, sFGR (sIUGR), acardiac (TRAP), monoamniotic twins and intrauterine death of one MC twin.SUMMARY STATEMENTS

• 1.Morbidity and mortality in twin pregnancies are most commonly related to: (1) chorionicity, (2) prematurity, (3) fetal growth restriction, and (4) congenital anomalies (high).
• 2.Virtually all monochorionic placentas have vascular anastomoses between the two placental cord insertions (high).
• 3.Besides prematurity and growth discordance, the vast majority of twin complications arise in monochorionic twin pregnancies (high).
• 4.Twin–twin transfusion syndrome affects approximately 10%–15% of monochorionic twin pregnancies (high).
• 5.The diagnosis of twin–twin transfusion syndrome is based on ultrasound findings of significant discordance in both amniotic fluid volume and bladder size (high). Cardiac dysfunction in the recipient twin or growth discordance often co-exist, but are not essential criteria for the diagnosis (high).
• 6.Fetoscopic laser ablation of the placental vascular anastomoses is the best treatment for twin-twin transfusion syndrome presenting before 28-30 weeks gestation, rather than amnioreduction or septostomy (high).
• 7.The Solomon laser technique decreases the risk of twin–twin transfusion syndrome recurrence and twin anaemia-polycythaemia sequence (high).
• 8.Twin anaemia-polycythaemia sequence occurs spontaneously in 4%–5% of monochorionic twin pregnancies (moderate). It typically develops later in pregnancy than twin–twin transfusion syndrome (usually >24–26 weeks gestation) (moderate). Twin anaemia-polycythaemia sequence may co-exist with twin–twin transfusion syndrome and has been reported in up to 13% of cases of TTTS in which the fetoscopic laser ablation procedure was incomplete (high).
• 9.Ultrasound features of twin anaemia-polycythaemia sequence are increasingly discordant middle cerebral artery peak systolic velocities, suggestive of anaemia in one fetus and polycythaemia in the other, often without significant amniotic fluid discordance (high). Other signs may include differential placental echogenicities and a “starry sky” liver in the recipient twin (moderate).
• 10.Selective fetal growth restriction in monochorionic twin pregnancies has been defined as an estimated fetal weight (EFW) of one twin below the 3^rd percentile, or at least 2 of the following four variables: (1) EFW <10^th percentile, (2) abdominal circumference <10^th percentile, (3) EFW discordance ≥25%, or (4) umbilical artery pulsatility index of the smaller twin >95^th percentile (high).
• 11.In monochorionic twins, estimated fetal weight discordance >25% and abnormal umbilical artery Doppler waveforms are independent risk factors for an adverse perinatal outcome. (high).
• 12.The ultrasonographic features of twin reversed arterial sequence are an amorphous, usually edematous, acardiac twin, which is retrogradely perfused via a placental artery-to-artery anastomosis by its healthy “pump” co-twin (high).
• 13.A large acardiac twin (e.g., an acardiac:“pump” twin abdominal circumference ratio ≥50%) may put its “pump” co-twin at risk of high-output cardiac failure (high). The overall risk of intrauterine death of the “pump” twin is approximately 30% before 18 weeks gestation (high).
• 14.If one of a monochorionic twin pair dies, the surviving co-twin may be at risk of neurological morbidity and intrauterine death (high). Imaging may not detect changes in the co-twin’s brain for several weeks after the death of its sibling (moderate).
• 15.Ultrasound features of monoamniotic twins include the absence of a dividing amniotic membrane, a single placenta, close proximity of placental cord roots, concordant sex and, commonly, cord entanglement (high).
• 16.Only 2%–4% of monoamniotic twins will develop twin–twin transfusion syndrome (high).
• 17.Structural anomalies, particularly cardiac, are more common in monochorionic twins than in dichorionic twins or singletons (high).
• 18.Conjoined twins are extremely rare and the organs/structures that are shared will determine the potential for surgical intervention and survival (high).

RECOMMENDATIONS

• 1.In spontaneously conceived pregnancies, we recommend using the larger of the two crown–rump lengths to estimate gestational age (conditional, moderate).
• 2.Viability, gestational age, chorionicity and amnionicity should be assessed between 11⁰ and 13⁶ weeks gestation in all multiple pregnancies (strong, high).
• 3.If chorionicity cannot be confidently established sonographically, pregnancies should be monitored as if they were monochorionic (conditional, moderate).
• 4.Twins should be labelled on antenatal ultrasound according to their lateral (right/left) or vertical (top/bottom) orientation, rather than their proximity to the cervix, and, ideally, that labelling should be maintained across all subsequent ultrasound examinations (strong, moderate).
• 5.A detailed anatomy scan should be performed at approximately 18–20 weeks gestation for all monochorionic twins (strong, high). Where the expertise is available, an early anatomy ultrasound can be performed at 12–14 weeks gestation (conditional, moderate).
• 6.In all twin pregnancies, cervical length should be assessed, either transabdominally or transvaginally, at the time of the anatomical ultrasound scan and, ideally, once more at around 23–24 weeks gestation (strong, moderate).
• 7.All monochorionic pregnancies should undergo ultrasound surveillance every 2 weeks from 16 weeks gestation until delivery to detect twin–twin transfusion syndrome, twin anaemia-polycythaemia sequence and selective fetal growth restriction (strong, high).
• 8.Ultrasound assessment of all monochorionic twins from 16 weeks onwards should include measurement of growth (fetal biometry), fetal bladder filling, and the single deepest pocket of amniotic fluid on both sides of the membrane, as well as umbilical and middle cerebral artery peak systolic velocity Doppler studies for each fetus (strong, high).
• 9.Monochorionic twins without complications should be delivered between 36 and 37 weeks gestation. Unless there are other obstetric contraindications, vaginal delivery is appropriate (strong, high).
• 10.If twin–twin transfusion syndrome or significant selective fetal growth restriction is suspected, the ductus venosus should be assessed (strong, high). Cardiac structure and function should be assessed in the recipient twin whenever twin–twin transfusion syndrome is suspected (strong, high).
• 11.For cases of twin–twin transfusion syndrome, urgent consultation with or referral to one of the fetal therapy laser centres in Canada is recommended, as fetoscopic laser ablation of placental vascular anastomoses is the best therapy for twin–twin transfusion syndrome (strong, high).
• 12.Ultrasonography should be performed weekly for 4 weeks after fetoscopic placental laser and then every 2 weeks following clinical resolution, with ongoing antenatal care shared or co-ordinated with the regional maternal–fetal medicine centre (strong, high). Assessment should include amniotic fluid volume in both sacs, bladder sizes, Doppler waveforms (middle cerebral artery peak systolic velocity, umbilical artery pulsatility index and ductus venosus), and intra-cranial anatomies, as well as measurement of cervical length and documentation of any chorio-amnion separation (strong, high).
• 13.Fetal intracranial anatomy should be carefully re-evaluated after an interval of at least 4 weeks following a laser procedure (strong, moderate).
• 14.Whenever monochorionic twin complications are encountered, including twin anaemia-polycythaemia sequence, selective fetal growth restriction, twin reversed arterial perfusion sequence, monoamnioticity, discordance for an anomaly, or a single intrauterine death, referral to, or at least consultation with, the regional maternal–fetal medicine program or fetal therapy centre is recommended (strong, high), so that all management options can be explored. The optimal management of twin anaemia-polycythaemia sequence has yet to be determined. (conditional, moderate).
• 15.When selective fetal growth restriction is suspected, fetal surveillance should be intensified and the pregnancy managed by referral to, or at very least with input from, a regional maternal–fetal medicine centre with expertise in this condition (strong, moderate).
• 16.In selective fetal growth restriction, timing of delivery should take into account gestational age, evidence of haemodynamic compromise as assessed by umbilical and middle cerebral artery and ductus venosus Doppler studies, and biophysical wellbeing (strong, moderate).
• 17.Whenever the death of one monochorionic twin is diagnosed early in pregnancy, colour Doppler ultrasonography should be used to exclude twin reversed arterial perfusion sequence, by confirming the absence of blood flow in the suspected demised twin (strong, high).
• 18.In twin reversed arterial perfusion sequence, especially with a large acardiac twin, occlusion of the circulation to the acardiac twin, either by laser, radio frequency ablation of the intra-fetal vessels or bipolar cautery should be considered (conditional, moderate).
• 19.After the spontaneous death of one monochorionic twin, surveillance for fetal anaemia by middle cerebral artery peak systolic velocity measurement should be instituted rapidly, as anaemia correlates with the risk of a hypotensive neurological injury (strong, high). The surviving twin may benefit from intrauterine transfusion (conditional, moderate). Fetal neurosonography and, ideally, MRI should be used to identify any potential cerebral injury; however, ultrasonographic evidence of injury may take 3-4 weeks to develop after the death of the co-twin (strong, high).
• 20.Care should be taken not to misdiagnose monochorionic-diamniotic pregnancies as monoamniotic, when one twin has anhydramnios (e.g., the donor in twin–twin transfusion syndrome) (conditional, moderate).
• 21.Monoamniotic twins are at high risk of cardiac abnormalities and should undergo a detailed anatomical ultrasound with particular emphasis on fetal cardiac evaluation (strong, high).
• 22.Monoamniotic twins should be monitored closely from viability onwards (either as out-patients or in-patients) and should undergo an elective caesarean delivery at approximately 33 weeks gestation (conditional, moderate).
• 23.Aneuploidy screening can be offered in monochorionic pregnancies as either combined prenatal serum screening (i.e., first-trimester screening or integrated prenatal screening, as available provincially) or cell-free fetal DNA analysis of maternal blood (conditional, moderate).
• 24.Invasive prenatal testing (chorionic villus sampling or amniocentesis) should be offered in the presence of a structural anomaly or abnormal genetic screening (strong, high). Amniocentesis from both sacs should be considered for discordant anomalies because of the rare possibility of heterokaryotypic anomalies in monochorionic twins (strong, high).
• 25.If indicated for discordance for an anomaly, selective termination of pregnancy in monochorionic twins must always be performed by a vascular occlusion method and never by intravascular fetal injection (strong, high).

     

Twin pregnancy with a complete hydatidiform mole and co-existent live fetus: two case reports and review of the literature

Introduction  The aim of this study was to report the clinical features, management, and outcome of two cases of complete hydatidiform mole with a coexisting viable fetus and to review the literature. Case reports  In this article, we report on the well-documented follow-up of two cases of twin pregnancies with complete hydatidiform mole and a normal fetus. Genetic amniocentesis showed normal fetal karyotype in both of two cases. In the first case, a live male infant was delivered by a cesarean section because of severe maternal bleeding at 29 weeks of gestation. In the second case, termination of pregnancy was performed due to early onset of severe preeclampsia and vaginal hemorrhage. Conclusion  The chances of a live birth have been estimated between 30 and 35% and the risk of persistent trophoblastic disease is similar to singleton molar pregnancies in complete mole with coexisting fetus pregnancy. Therefore, in these pregnancies, expectant management instead of termination of pregnancy can be suggested.