you can see this 

R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS. To download R, please choose your preferred CRAN mirror.

http://www.r-project.org/

Our group has looked at this--content is variable, and mostly accurate but not necessarily that useful.  A second project is in preparation as well.

http://informahealthcare.com/eprint/mVnTda3wd4wBK5qtknIe/full

Article Social media messaging in pregnancy: Comparing content of Te...

While I have not reviewed them, Text4baby was a collaborative effort by several government agencies and industry partners.It seems to be supported on our Philadelphia Health Department's website. Research and evaluation of it is listed here https://www.text4baby.org/index.php/about/data-and-evaluation.

Surprisingly, as a direct provider of prenatal care in a public health community center, no one has trained me or my colleagues at the point-of-care how to get our pregnant patients to benefit from it. I only know because of my academic appointment in public health.

Thanks for your response. I had read the Text4baby paper but  it didn't really identify if the information provided was actually evidence based, mediated by health professionals and  how pregnant women actually benefited.

There are so many people on the internet so willing to give advice to pregnant women, when this is precisely the time that women need to be extremely discerning in accepting the information they obtain.