Antenatal diagnosis and management of monoamniotic twins

Double survival of monoamniotic twins is rare. Three consecutive cases in which double survival occurred are presented. Accurate antenatal diagnosis, intensive fetal surveillance, and operative delivery should improve neonatal outcome.     

Inpatient versus outpatient management of monoamniotic twins and outcomes

We sought to evaluate whether early (24 to 28 weeks gestation) hospitalization of monoamniotic twins, with close fetal surveillance, and delivery at 32 to 34 weeks gestation, would significantly improve the perinatal morbidity and mortality compared with an outpatient management strategy. A multicenter, retrospective record review was undertaken. Records of all monoamniotic twins were collected for a 10-year period. Monoamniotic twins were identified using intensive care nursery, ultrasound, and pathology records. Data were collected on inpatient versus outpatient management strategies and the perinatal/maternal outcomes and complications. Twenty-three sets of monoamniotic twins were included in the study. Eleven sets were managed using an inpatient strategy and 12 sets were managed using an outpatient strategy. There were no fetal deaths in the inpatient group and there were three fetal deaths in the outpatient group. Inpatient management of monoamniotic twins should be considered.     

Concordant occipital encephalocele in monoamniotic twins

Anomalies occur with a greater frequency in twin gestations. Due to its multifactorial inheritance, twins are usually discordant for encephalocele. We present a case of monoamniotic twins concordant for occipital encephalocele and discordant for lung and cord anomalies.Ultrasonographic examination at 17 weeks' gestation revealed occipital encephalocele in both fetuses. The maternal serum level of alpha-fetoprotein was increased. Fetal autopsy revealed occipital encepaholocele in both twins and right pulmonary hypoplasia and one umbilical artery in one sibling. Monoamniotic twins concordant for encephalocele occur with extreme rarity. To the best of our knowledge, monoamniotic twins concordant for this neural tube defect have not been previously reported.     

Current antenatal management of monoamniotic twins: a survey of maternal-fetal medicine specialists

Objective: To assess current management of monoamniotic (MA) twins by US maternal-fetal medicine providers. Methods: We conducted a mailed survey to members of the Society for Maternal-Fetal Medicine regarding fetal surveillance practices and preferred gestational age (GA) for elective delivery with respect to MA twins. Results: Responses from 837 (43%) were received with most (83.9%) recommending elective admission for inpatient monitoring, 53.5% favoring 26–28 weeks as earliest GA for admission and 75% performing intermittent fetal monitoring (of these 81% monitored 2–3 times/day). Respondents in practice less than 10 years were less likely to use outpatient management (p < 0.05). Median GA for elective delivery was 34 weeks but was higher for those who favored outpatient management, admitted >28 weeks, and were private practitioners (p < 0.05). Conclusions: Despite a paucity of evidence, most practitioners admit MA to perform daily intermittent fetal monitoring and deliver at 34 weeks. Antenatal management protocols may also influence timing of delivery. Due to their rarity, a national registry may be a better tool to analyze the outcomes of these pregnancies.     

Monochorionic monoamniotic twins: neonatal outcome.

BACKGROUND: Monochorionic monoamniotic twins (MoMo) occur in one of 10,000 pregnancies. Cord entanglement, malformations, twin-to-twin transfusion syndrome (TTS) and prematurity are responsible for their high perinatal morbidity and mortality. OBJECTIVE: To report our experience with 36 sets of MoMo twins (1990 to 2005) and to provide updated information for counseling. METHODS: Chorionicity was determined by placental examination, gestational age and TTS clinically and by sonography. Intrauterine growth restriction (IUGR) was diagnosed with a twin-specific nomogram. RESULTS: Cord entanglement was observed in 15 pregnancies, but only one twin with entanglement and a true knot, experienced related morbidity. Four of 71 live births were IUGR. Malformations were diagnosed prenatally (one hypoplastic left heart and one body stalk) and postnatally (one vertebral anomalies-anal atresia-tracheoesophageal fistula-renal defect (VATER) and two lung hypoplasias). Twin-to-twin transfusion syndrome affected three sets of twins. Five twin sets delivered before 31, 19 sets at 31 to 32 and 12 sets at 33 to 34 weeks. Six of 71 (8%) twins died (four malformations, one TTS and one 26 weeks premature). Head ultrasounds in 59 of 65 survivors showed two (3%) periventricular leukomalacia, five (9%) Grade I-II intraventricular hemorrhage and 52 (88%) normal. CONCLUSIONS: Monochorionic monoamniotic twins remain a group at risk for cord entanglement, congenital malformations, TTS and prematurity. Although their neonatal mortality and morbidity is high, outcomes for survival are better than anticipated.     

Single intrauterine fetal death in monoamniotic twins due to cord entanglement

A case of monoamniotic twin intrauterine fetal death of one of the fetuses is presented. The death was most probably caused by cord entanglement and thrombosis. A discussion on incidence, etiology and pathology is included.     

The management of acardiac twins: a conservative approach

OBJECTIVE: Optimal management of acardiac twin pregnancies is controversial. Data suggest a 50% mortality rate in the "pump" twin when the pregnancy is managed expectantly. Because of increased antenatal diagnosis, outcomes in expectantly managed cases may be better than reported. Our objective was to determine the outcome of expectantly managed acardiac twin pregnancies. STUDY DESIGN: All cases of antenatally diagnosed acardiac twins delivered in our community between 1994 and 2001 were ascertained. All were managed expectantly. Perinatal outcome of pump twins was the primary outcome variable. RESULTS: Ten cases were identified. Nine women were delivered of healthy pump twins. There was one neonatal death. The mean gestational age at delivery was 34.2 weeks. The mean weights of the pump and acardiac twins were 2279 g and 1372 g, respectively. CONCLUSION: Neonatal mortality of pump twins in antenatally diagnosed acardiac twin pregnancies may be considerably less than reported. Expectant management with close antepartum surveillance deserves consideration.     

Improved perinatal survival of monoamniotic twins with intensive inpatient monitoring

OBJECTIVE: The purpose of this study was to evaluate the impact of routine hospitalization for fetal monitoring on the perinatal survival and neonatal morbidity of monoamniotic twins. STUDY DESIGN: This was a multicenter retrospective cohort analysis of 96 monoamniotic twin gestations from 11 university and private perinatal practices. Overall mortality rates were calculated. The risk of intrauterine fetal death and neonatal morbidity was compared among women who were observed as inpatients versus outpatients. RESULTS: The overall mortality rate from enrollment was 19.8% (mean gestational age at enrollment, 17.4 weeks). The perinatal mortality and corrected perinatal mortality rates were 15.4% and 12.6%, respectively. Eighty-seven women had both twins who were surviving at 24 weeks of gestation; 43 women were admitted electively for inpatient surveillance at a median gestational age of 26.5 weeks; the remainder of the women were followed as outpatients and admitted only for routine obstetric indications (median gestational age, 30.1 weeks). No intrauterine fetal deaths occurred in any hospitalized patient. The risk of intrauterine fetal death in women who were followed as outpatients was 14.8% (13/88) versus 0 for women who were followed as inpatients (P < .001). There also were statistically significant improvements in birth weight, gestational age at delivery, and neonatal morbidity for women who were followed as inpatients. CONCLUSION: We observed improved neonatal survival and decreased perinatal morbidity among women who were admitted electively for inpatient fetal monitoring.     

Genetic amniocentesis in multiple gestation: a new technique to diagnose monoamniotic twins

Injection of indigo carmine dye mixed with air into the amniotic sac under ultrasound guidance during genetic amniocentesis on twins is described. This technique can reliably detect monoamniotic twins and clearly differentiate diamniotic twins, thereby facilitating accurate needle insertion into the second sac during amniocentesis.     

The psychosocial impact of inpatient management of monoamniotic twin gestations

Objective: Monoamniotic twins require unique considerations in clinical management that challenge both clinicians and patients. The aim of this study was to assess the psychosocial impact of inpatient antepartum versus outpatient management for these patients.

Methods: Women with a history of a monoamniotic twin pregnancy between 2002 and 2012 were identified through a social media group and invited to participate in an original survey regarding their clinical management and psychological well-being during gestation. Results between patients managed with inpatient versus outpatient protocols were compared using the Fisher exact test.

Results: Participants (n?=?197) were multinational. Planned inpatient management after 23 weeks gestation was reported in 76.2% of respondents. Participants in both groups endorsed persistent feelings of hopelessness or despair related to their pregnancies (42.4% of inpatients versus 24.1% of outpatients, p?=?0.089). Relationship strain between participants and their partners was similar in both the groups. Participants in the outpatient group were more likely to report feelings of guilt related to their infrequent monitoring (p?=?0.01). Patient satisfaction with care was higher in the inpatient group.

Conclusions: Inpatient management did not significantly increase measures of psychosocial stress as compared to outpatient management. Participants in the outpatient group reported feelings of guilt about their infrequent monitoring. Our findings provide increased understanding of the patient experience in these rare and challenging clinical circumstances.     

Ultrasonographic diagnosis of thoracopagus conjoined twins in a monoamniotic triplet gestation.

Ultrasonographic examination at 16 weeks 5 days' gestation diagnosed a monoamniotic triplet gestation complicated by thoracopagus conjoined twins. After pregnancy termination, the ultrasonographic diagnoses were confirmed by pathologic examination. In reporting the first ultrasonographically diagnosed monamniotic triplets with conjoined twins, we demonstrate that a systematic evaluation by twin-derived ultrasonographic techniques may permit correct diagnosis of unusual triplet pregnancies.     

Survival rates of monoamniotic twins do not decrease after 30 weeks' gestation

A search of pathology records from the years 1967 to 1988 at Women and Infants' Hospital of Rhode Island (138,232 live births) revealed 24 sets of histologically confirmed monoamniotic twins. All records were available for review. Among the 17 sets of monoamniotic twins that reached 30 weeks' gestation with at least one twin still alive, there were no further fetal deaths. The risks of early delivery in these pregnancies appear to outweigh the risk of fetal death as a result of monoamniotic status alone. These data do not show an advantage to early delivery.     

Vaginal delivery of monoamniotic twins with umbilical cord entanglement. A case report

BACKGROUND: Monoamniotic twinning is frequently complicated by umbilical cord entanglement and fetal death. Should vaginal delivery take place, this may present as an acute intrapartum emergency. CASE: A 26-year-old woman, gravida 3, para 2, presented in the second stage of labor and gave birth to a macerated, stillborn infant weighing 1,340 g. At the time of delivery it was not known that this was a twin pregnancy. Delivery was achieved only after division of a cord around the neck; it turned out to be that of a live, second twin. This infant, weighing 2,530 g, was delivered by rapid breech extraction and made a satisfactory recovery. CONCLUSION: When multiple pregnancy or monoamniotic multiple pregnancy has not been excluded, a nuchal cord might be that of an undiagnosed second twin.