Monoamniotic twin pregnancy discordant for lethal open cranial defect: management dilemmas

Prenatal diagnosis and management of monozygotic twins discordant for severe fetal abnormalities

OBJECTIVE

We present prenatal diagnosis and management of monozygotic (MZ) twins discordant for severe fetal abnormalities.

CASE REPORT

A 36-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, and hydrops fetalis, a giant cystic hygroma of 5 × 3.5 cm and left hydronephrosis in a co-twin. The other co-twin was structurally normal. Amniocentesis revealed a karyotype of 46,XY in both co-twins. Simultaneous polymorphic DNA marker analysis using the DNAs extracted from maternal blood and uncultured amniocytes confirmed MZ twinning. The woman underwent a successful selective fetal reduction by radiofrequency ablation at 22 weeks of gestation. At 28 weeks of gestation, premature rupture of membranes occurred, and a 1280-g normal male baby and a 275-g dead malformed co-twin were delivered. The normal co-twin was phenotypically normal and was doing well at age seven weeks.

CONCLUSIONS

Prenatal diagnosis of MZ twins discordant for structural abnormalities should include a differential diagnosis of MZ twinning, and a zygosity test is necessary under such a circumstance.

Sonographic spectrum of first-trimester fetal cephalocele: review of 35 cases

OBJECTIVE

To describe the sonographic features of fetal cephalocele diagnosed at the time of first-trimester ultrasound screening for aneuploidy.

METHODS

This was a retrospective review of cases of cephalocele diagnosed in the first trimester at four fetal medicine referral centers. Once diagnosis was suspected, a transvaginal ultrasound examination was offered to improve depiction of the cranial defect and enhance examination of fetal anatomy, with special attention given to the location, size and content of defects. To assure consistency in diagnosis, representative pictures and videoclip sequences of the cranial defect were obtained and reviewed by at least two authors. Cases were classified and compared with the assessment made at diagnosis.

RESULTS

Of the 35 affected fetuses identified, 33 were of a singleton pregnancy and two were of twin pregnancies in which the other fetus was unaffected. The lesion was classified as a cranial meningocele in 13 (37%) cases and as an encephalocele in 22 (63%). The bone defect was occipital in 27 (77%), frontal in three (9%), parietal in three (9%) and non-classifiable in two (6%). Twelve (34%) were considered as small in size, 11 (31%) as medium and 12 (34%) as large. There were no reported cases of aneuploidy; however, four (11%) cases were associated with Meckel-Gruber syndrome, two (6%) with a disruptive syndrome and one (3%) with skeletal dysplasia. Eight (23%) pregnancies were lost to follow-up. Parents opted for termination of pregnancy in 21 of the 27 remaining cases and, of the six ongoing pregnancies, four patients miscarried or the fetus died in utero during the second trimester, one liveborn infant died shortly after delivery and one underwent neonatal surgery for an isolated cranial meningocele and is currently doing well.

CONCLUSIONS

First-trimester sonographic diagnosis of cephalocele is accomplished easily with a detailed examination of the skull contour at the time of routine assessment of the axial and sagittal views of the head for measurement of the biparietal diameter and nuchal translucency, respectively. However, the sonographic features are highly variable. A significant proportion of cases are associated with genetic or disruptive syndromes. Prenatal diagnosis of cephalocele in the first trimester was associated with a high rate of termination of pregnancy and early intrauterine fetal demise. Only one fetus in this series survived and is neurologically intact; therefore, the prognosis of this condition remains poor.

[Selective termination of pregnancy for monochorionic twins: a national survey of professional practice]

OBJECTIVES

Selective Termination of Pregnancy (STOP) for discordant fetal condition in monochorionic twin pregnancy is a rarely performed procedure raising technical and ethical considerations. There are no epidemiological data available in France concerning STOP and no guideline or scientific consensus on how or when to perform has been published.

MATERIALS AND METHODS

We conducted a study of national practice using a declarative questionnaire sent by e-mail to each medical coordinator of every 48 Multidisciplinary Center for Prenatal Diagnosis in France. The questions focused on the issues of 2010 and 2011. Two reminders were sent in case of no answer.

RESULTS

The response rate to the questionnaire was 56 %; 81 % of centers have experienced at least once during the two years 2010-2011 a discordant fetal anomaly in monochorionic twin pregnancy. Only 59 % of centers perform all the techniques of STOP. When interruption of the umbilical blood flow is considered, bipolar forceps coagulation is the most used (75 %). Achieving STOP during a cesarean section is a common practice (75 % of centers). Locoregional anesthesia is the preferred mode of anesthesia for STOP.

DISCUSSION AND CONCLUSION

STOP on monochorionic twin pregnancy is not practiced in all Multidisciplinary Center for Prenatal Diagnosis in France. The most widely practiced and most studied technique is bipolar forceps coagulation. The option of an expectant management should always be considered and its risks should be balanced with those of STOP. The practice of STOP during cesarean section is not unusual.

Differences between selective termination of pregnancy and fetal reduction in multiple pregnancy: a narrative review

Although selective termination of pregnancy and fetal reduction in multiple pregnancy both involve the termination in utero of the development of live fetuses, these two procedures are different in several aspects. Nevertheless, several authors tend to amalgamate and confuse their psychosocial consequences and the ethical issues they raise. Therefore, this narrative review, derived from a comparative analysis of 91 articles, shines a light on these amalgamations and confusions, as well as on the medical, contextual, experiential and ethical differences specific to selective termination and fetal reduction.

Monoamniotic twins with one fetal anencephaly and cord entanglement diagnosed with three dimensional ultrasound at 14 weeks of gestation

A 29-year-old pregnant woman with parity 0-0-0-0 was diagnosed with monoamniotic twin pregnancy discordant for anencephaly at 14 weeks gestation. Umbilical cord entanglement, which is an important cause of fetal death in monoamniotic twins, was confirmed by three-dimensional ultrasound. Cesarean section was performed at 34 weeks of gestation, and the normal newborn infant was discharged without any complications. We report a case of monoamniotic twin pregnancy discordant for anencephaly and diagnosed with cord entanglement by three-dimensional ultrasound at 14 weeks of gestation, and now report it along with a literature review.