Читать книгу Genetic Disorders and the Fetus - Группа авторов - Страница 39

It is an anachronism that preconception genetic counseling in the 21st century, despite being recognized as important, is not widely practiced.^{401, 402} Expectations at the first preconception visit include routine documentation of the medical, obstetric, and family history, the latter regarded arguably as the most important “genetic test.”⁴⁰³ It is now possible to prenatally diagnose all monogenic disorders in which the culprit gene is known. Since 6,739 have phenotypes thus far with recognized single genes,² it is very important for the physician to obtain and record the exact name of the genetic disorder(s) in the family. A history of “muscular dystrophy,” given numerous types, would, for example, not be useful. Patients need a brief explanation as to why they need to obtain the precise information, and the physician's request documented. Review of medical records, photographs (e.g. previous stillbirths), and pertinent autopsy reports, radiographs, brain scans, and chromosome or other special laboratory reports may be necessary, as well as referral for genetic counseling. Physical examination and necessary special tests also focus on acquired and genetic disorders that could, during pregnancy, threaten maternal and/or fetal welfare.

Previously undiagnosed/undetected disorders may be determined for the first time at this visit and may be important for planned childbearing and the selection of future prenatal diagnostic tests. There is a need to insist that the male partner attend the preconception visit (or absolutely the first prenatal visit), providing an opportunity to detect at least obvious genetic disorders and solidify information possibly provided earlier about his family history. The senior author recalls, over many years during prenatal diagnosis counseling for other issues, diagnosing various disorders in male partners who were wholly unaware of their conditions, including osteogenesis imperfecta, Treacher–Collins syndrome, tuberous sclerosis, neurofibromatosis, Charcot–Marie–Tooth (type 1A) disease, limb girdle muscular dystrophy, facioscapulohumeral muscular dystrophy, blepharophimosis, mitral valve prolapse, the XYY male, and spinocerebellar ataxia.

The first preconception visit also serves to instruct about the need for folic acid supplementation for the 70 percent avoidance of NTDs (see Chapter 10) and about diabetic control, management of obesity, cessation of illicit drugs, medications, smoking and alcohol. Referral to other specialists (e.g. neurologists), for tailoring medication requirements to safer and possibly less teratogenic agents (e.g. epilepsy, acne), is also recommended. This is also the time for specialists caring for the same patient to confer about the planned care of their patient through pregnancy and for documentation of that interaction to be made.