Handbook of Genetic Counseling/Spina Bifida

Spina Bifida Quote Risks Spina bifida is usually an isolated birth defect. Level II Ultrasound At 18-20 weeks, a high resolution, targeted ultrasound examination can be done to carefully and specifically examine the baby's spine. This is noninvasive and may provide reassurance but cannot be used as a diagnostic tool. If no evidence of a NTD is seen, it cannot be guaranteed that the baby does not have a NTD. Amniocentesis If the triple screen results indicate an increased risk for a NTD, one may choose to have an amniocentesis, which is a more invasive, but more diagnostic test. What is it? Procedure used to obtain a small sample of fluid from the fluid-filled sac that surrounds the fetus Performed at 15 weeks gestation or later 15-18 weeks is optimal because it leaves the patient with options 22 weeks is probably the latest it can be done leaving the option of elective abortion Amniotic fluid contains the fetus's urine as well as other cells from the skin, throat, and digestive tract Fluid is studied in the lab for abnormalities What can it tell me? Amnio can detect certain abnormalities in the fetus. Chromosome abnormalities NTDs (Spina Bifida) It can determine the sex of the baby. What can it NOT tell me? Amnio cannot detect all birth defects or mental retardation. For example, congenital heart defects, cleft lip & palate cannot be seen. Also the severity of the defect cannot be known from amnio. Exactly what does the procedure involve? Show figure of amniocentesis. You will lie down on your back with hands behind your head. Your abdomen will be cleaned with alcohol or iodine. A local anesthetic may be applied to your stomach. Ultrasound will be used to locate the position of the baby and the placenta and to find a safe spot for the needle. A long, thin needle will be inserted through the skin, into the uterus. The first few cc's of fluid will be discarded because they probably contain contamination from your cells. Then a small amount (about 1-2 tablespoons) of fluid is removed and the needle is withdrawn. The procedure itself usually takes ~5 minutes. The baby will quickly replace the fluid that is removed. The baby's heartbeat will be monitored by ultrasound. Fluid will be sent to the lab and results are available in 1-2 weeks. There is a small possibility of lab error or lack of cell growth In this case, the procedure would have to be done again. What will it feel like? If an anesthetic is used, you may not feel the needle enter the skin, but you will still feel it enter the uterus. This is described as a sharp pain, like a menstrual cramp that usually lasts a few seconds. You may also feel some cramping after the procedure. You should avoid strenuous activity for 24 hours after the procedure. Call your doctor immediately if you experience abdominal pain or cramps, vaginal bleeding, leakage of clear fluid from the vagina, fever, or anything else unusual. Approximately 2% of women experience light bleeding or spotting. What are the risks? The risk of miscarriage is between 1/400 and 1/200. This means that the added risk for pregnancy loss attributable to the procedure is 0.5% or less. There is a risk of uterine infection but this is less than 1 in 1,000 There is a remote chance that birth defects can be caused by the amnio (0.1%). There are special considerations for mothers who are Rh negative. They need to take RhoGam after the amnio procedure. Other Resources Spina Bifida Association of America SBAA 1-800-621-3142 Review and summarize major points www.sbhac.ca spina bifida association of Canada Elicit final questions and concerns Reporting of the Results If they are having a procedure, discuss how they would like to receive the results Appointment, phone call, etc. Who will contact them? Discuss the options: elective abortion, adoption, etc.