To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Structural fetal anomalies complicate up to 5% of pregnancies and an underlying chromosomal or genetic etiology underlies up to half of cases. Understanding the fetal genome is increasingly key in attempting to make a prenatal diagnosis and in delineating a prognosis for the baby. Over the past decades, the field of prenatal genomics has advanced exponentially, beginning with the conventional ‘full’ karyotype available in the 1960s and going up to the present day and beyond with the application of next-generation sequencing (NGS) (Figure 4.1). Current and potential future advances in prenatal diagnostics will allow couples to make more informed decisions prospectively about their pregnancies in addition to aiding decisions on and the development of fetal therapies . In the wake of advancing technologies and large prospective studies such as the United Kingdom’s ‘proof of principle’ 100 000 Genomes Project  and the Prenatal Assessment of Genomes and Exomes (PAGE) study , the degree of information obtained and turnaround time of results with the development of more sophisticated bioinformatic analytical pathways is likely to improve rapidly. Fetal medicine subspecialists, obstetricians, pediatricians, geneticists, genomic scientists and genetic counselors have a responsibility to stay up to date with this wealth of advances so that couples can be informed accordingly.
Twin-to-twin transfusion syndrome (TTTS) is a complication unique to monochorionic (MC) twins and affects 10–15% of MC twins, including MC twin pairs in higher order multiple pregnancies. The disease has fascinated obstetric specialists since it was first described in 1875 , when it was recognized as a condition not amenable to treatment and with a very high perinatal loss rate. Since then, TTTS has provided many challenges, not only in terms of deciphering the underlying pathogenesis but also in attempting to alter the clinical course of a condition with a >90% perinatal loss rate untreated and very high (>50%) neurological morbidity in any surviving babies [2, 3]. Outcomes improve dramatically with treatment, which will be discussed in detail in Chapters 32, 33, and 35. However, even with treatment 12% of TTTS pregnancies will end with a double fetal loss, and only 62% with two survivors .