The FDA is now saying the popular 3D ultrasounds, which give parents that first detailed look at their baby, may be unsafe.

The reason is they can last up to an hour, far longer than the traditional 2-d ultrasound at the doctor, and the long term effects of the longer ultrasound are unknown.

Dr. Rebecca Poole, with Affiliates for Women's Health in College Station, says there's another potential problem with these keepsake ultrasounds.

Many times, the 3D imaging companies don't have an actual doctor on staff who can interpret the scan, which can lead to very worried women.

Dr. Poole says, "If they see an anomaly and they are told there is anomaly, there's not somebody on staff there who can immediately explain it to them, so they have to wait for their doctors appointment. that can cause a huge amount of stress."

Dr. Poole says if you do decide to get a 3D ultrasound, despite the FDA's warning, just make sure you also get the 2D ultrasound at your doctors.

That is necessary to truly get a good idea of how your baby's organs are developing.

The FDA's complete report on 3D ultrasounds is posted online.