Open fetal surgery for myelomeningocele

Despite efforts at prevention through the use of preconception folic acid, spina bifida remains one of the most common congenital anomalies of the central nervous system that is compatible with life. It is, however, associated with a significant degree of lifelong morbidity. The development of open fetal surgery for myelomeningocele (MMC) has been a long process but one that serves as a model for how new procedures and technologies need to be properly evaluated before being brought into mainstream medical practice. Even so, risks and benefits need to be evaluated for each patient. The currently available studies have been carried out on a highly selected patient population where the fetal findings provided the maximum opportunity for benefit from prenatal closure of the MMC defect. There is the potential that as the surgery becomes more widely available, pressure will be brought to bear to perform surgery in cases where the likelihood for benefit is decreased and yet the risks are not. The only way to duplicate the results of the current studies is to follow the methodology and criteria that were used in the studies. This will mean that not every fetus with an MMC will be a candidate for in utero surgery. The balance of risk to benefit will continue to evolve as further technological advances are evaluated and more follow-up information is obtained. Copyright © 2011 John Wiley & Sons, Ltd.     

Managing twins discordant for fetal anomaly

An excess of structural anomalies is observed in twins compared to singletons. Approximately 1–2% of twin pregnancies may face the dilemma of expectant management versus selective termination following diagnosis of an anomaly affecting only one fetus. If the option of selective fetocide is considered, the main variable determining the technique to achieve this aim is chorionicity. In a dichorionic pregnancy, passage of substances from one twin into the circulation of the co-twin is unlikely due to the lack of placental anastomoses, hence KCl can be injected safely into the circulation of the affected twin to produce fetal asystole. In monochorionic twin pregnancies, selective termination needs to be performed by ensuring complete and permanent occlusion of both the arterial and venous flows in the umbilical cord of the affected twin, in order to avoid acute haemorrhage from the co-twin into the dying fetus, which may lead to death or organ damage. Bipolar cord coagulation under ultrasound guidance is associated with approximately 70–80% survival rates. Copyright © 2005 John Wiley & Sons, Ltd.     

Syndromic associations with congenital anomalies of the fetal thorax and abdomen

Anomalies of the thorax and abdomen can be found in a number of genetic syndromes. Whilst it may not be possible to make a definitive diagnosis before birth, knowledge of the potential associations can be useful for the prenatal diagnostician when examining the fetus and counselling the parents. In this article, we describe conditions where other features may be detectable using prenatal ultrasound. We describe the features, potential diagnostic aids and prognosis. The tables list other potential features that may be identified. The range of conditions that can occur emphasises the value of genetic input in the management of a fetus with an apparently normal karyotype and multiple anomalies, the need to save material for future molecular analysis and the requirement of a detailed examination after delivery. These are needed in order to make accurate diagnoses and advise parents with regard to recurrence risks and the potential for prenatal diagnosis in future pregnancies. Copyright © 2008 John Wiley & Sons, Ltd.     

Update on selective reduction

Over the past 25 years fetal reduction has been utilized to reduce the risks of higher-order multiple pregnancies that have resulted from overly successful infertility therapies. The demographics of multiple pregnancy patients have evolved over the past decade, with increasing proportions coming from IVF as opposed to ovulation induction, being older and a higher proportion with donor eggs. Genetic diagnosis prior to reduction is becoming more common and is very safe in experienced hands. For all starting numbers, including twins, reduction to a lower number of fetuses reduces fetal losses, prematurity, and infant mortality and morbidity. Copyright © 2005 John Wiley & Sons, Ltd.