One benefit that you have listed is that the discovery of a neural tube defect would change your plans for the birth. I'm not sure what that change of plans might be, but if that is your only concern, why not just take a quick peek in the 3rd trimester? That's plenty of time to decide that you will have your baby in the hospital instead of at home or in a free-standing birth center and whether the condition is serious enough to warrant planning a c/sec. (Neural tube defects, you should know, are not a black & white issue. They can range from extremely minor to severe, as can, no doubt, other congenital anomalies.)
On the minus side, you have articulated a concern that is on the money: "getting to know the baby." If you would not end the pregnancy based on what is shown on the ultrasound, you will have, as the Dutch call it, "spoiled the pregnancy." You will almost certainly spend the rest of the pregnancy in anxiety, distress, and grieving for something that cannot be treated until the baby is born. But there is worse: Ultrasound scans not infrequently give ambiguous news or even an erroneous diagnosis. Then you will not only worry your way through the rest of the pregnancy for nothing, but studies have shown that even after the baby is born and shown to be healthy, women may continue to worry that all is not well with their child. A mother who is unduly anxious and hypervigilant about her baby is going to be a different sort of mother from one who is not, and that could have subtle, yet powerful, consequences for their relationship.
As for potential harms of exposing the unborn baby to ultrasound in the 2nd trimester, I haven't researched this recently, but I would think that the odds are that risk of harm would be minimal with a single abdominal scan after the 1st trimester. It's hard to prove a negative, though. There is always the possibility that if the study measured something else or used a bigger population, it might detect an association. What I would do in your shoes if I were going ahead with the scan is:
-- To ensure greatest accuracy and reliability of diagnosis, have the scan done by a certified sonographer in a facility that specializes in imaging or a hospital imaging department. Don't just have your ob do it in the office. Ask for the qualifications of the person doing the scan and the person reading it. Don't assume; unless things have changed fairly recently, unlike, say, your hairdresser, there are no regulations regarding training and experience for ultrasonographers. Obstetricians can be "trained" as part of a weekend cruise junket.
-- Discuss what, specifically, you want to know because knowing it could influence your plans. Then find out how to get the briefest possible exposure that will find those things out. In other words, don't agree to a fishing expedition of whatever length and exposure is the usual protocol.
-- Discuss whether an abdominal scan is ordered, where the probe is moved across your belly, or a vaginal scan, where the probe is inserted vaginally. For one thing, there may be a difference in risk since the probe is inches from the baby with very little in between. Also, some women have bluntly described a vaginal scan as "rape with a foreign object." Certainly, if you have sexual assault or abuse in your past, I would leery of agreeing to a vaginal scan. At the very least, you don't want any surprises on this point.
By: Henci Goer
All Times America/New_York
Please note that this Forum is intended to help women make informed decisions about their care. The content is not a substitute for medical advice.