Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstétrique et gynécologie du Canada : JOGC
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J Obstet Gynaecol Can · Sep 2009
Review Practice GuidelineEvaluation of prenatally diagnosed structural congenital anomalies.
To provide information to genetic counsellors, midwives, nurses, and physicians who are involved in the prenatal care of women dealing with prenatally diagnosed isolated or multiple structural congenital anomalies. ⋯ 1. When a fetal structural anomaly is identified, the pregnant woman should be offered a timely consultation with a trained genetic counsellor and with a maternal-fetal medicine specialist and/or a medical geneticist. The counselling should be unbiased and respectful of the patient's choice, culture, religion, and beliefs. (III-A) 2. Patients should be informed that prenatal ultrasound at 18 to 20 weeks can detect major structural anomalies in approximately 60% of such cases. (II-2A) 3. When a fetal structural anomaly is suspected or identified, a referral to a tertiary ultrasound unit should be made as soon as possible to optimize therapeutic options. (II-2A) 4. In ongoing pregnancies with fetal structural anomalies, ultrasound examination should be repeated (at a frequency depending on the anomaly) to assess the evolution of the anomaly and attempt to detect other anomalies not previously identified, as this may influence the counselling as well as the obstetrical or perinatal management. (II-2B) 5. Once a fetal structural anomaly is identified by 2-D ultrasound, other imaging techniques such as fetal echocardiography, 3-D obstetrical ultrasound, ultrafast fetal MRI, and, occasionally, fetal X-ray and fetal CT scan (using a low-dose protocol) may be helpful in specific cases. (II-2A) 6. Parental imaging should be considered in specific cases, depending on the fetal anomaly identified (e.g., potential dominant inheritance). (III-A) 7. Parental blood testing and invasive prenatal testing may also be required to clarify the diagnosis for a fetus with isolated or multiple structural anomalies. (II-2A) 8. Women should receive information regarding the abnormal ultrasound findings in a clear, sympathetic, and timely fashion, and in a supportive environment that ensures privacy. Referral to the appropriate pediatric or surgical subspecialist(s) should be considered to provide the most accurate information possible concerning the anomaly or anomalies and the associated prognosis. (II-2 B) 9. Parents should be informed that major or minor fetal structural anomalies, whether isolated or multiple, may be part of a genetic syndrome, sequence, or association, despite a normal fetal karyotype. (III-A) 10. If early or urgent postnatal management may be required, delivery at a centre that can provide the appropriate neonatal care should be considered. (III-A) 11. When any congenital structural anomaly has been identified prenatally, a comprehensive newborn assessment is essential for diagnosis and counselling on the etiology, prognosis, and recurrence risk for future pregnancies, especially when the etiology has not been clearly identified prenatally. (III-A) 12. In cases of termination of pregnancy, stillbirth, or neonatal death, the health professional should encourage the performance of a complete autopsy by a perinatal or pediatric pathologist to provide maximum information on the diagnosis and etiology of the structural fetal anomaly or anomalies. When a complete autopsy is refused, the health professional should encourage the performance of at least a partial or external autopsy (including X-rays and photographs). (III-A) VALIDATION: This committee opinion has been prepared by the Genetics Committee of the SOGC and approved by the Executive of the SOGC.