You can go to the MIdwifery Today main site by clicking the button above and do a search of ultrasound articles that have appeared in Midwifery Today.
Henci Goer has done quite a bit of work "researching research". You can go to www.hencigoer.com and check out what she has. She's very approachable, knowledgeable, and helpful so feel free to contact her directly through the site. I love Henci and all the grunt work she does to analyze and interpret the research that's out there on a variety of subjects but I find her especially helpful and a go-to source for ultrasound.
Another place to try is www.sarahbuckley.com. Dr. Buckley has information about ultrasound in her book Gentle Mothering but she also has other info on her site.
You can also try www.childbirthconnection.org. I'm not too sure how much info on ultrasound and conception is available, but worth a read to see what's what.