Label fetal illustrations/descriptions by "fertilization age" rather than "gestational age".
I am visiting your page "A Woman's Right to Know: Characteristics of an Unborn Child." (http://www.azdhs.gov/phs/owch/informed-consent/right-to-know/unborn.htm) At the bottom of the page you give images and information about the unborn child according to "Gestation Periods". I was confused for a while because I am looking at an embryology textbook at, for instance, a 4-week embryo and it is very different from the illustration you provide. I finally realized that this is because you are going by "gestational age", which you explain at the top of the page is from the beginning of the last normal period. This is confusing, though, because when someone looks at a picture of a 4-week embryo they expect to see an embryo that is 4-weeks old (in spite of your explanation at the top). In actuality the 4-week embryo that you illustrate is only 2 weeks old, since fertilization normally takes place about 14 days after the beginning of the last menstrual period. It would make more sense to put the information/illustrations up according to how old the embryo/fetus actually is (i.e., “fertilization age”). Otherwise I think you will be giving an erroneous impression to most of the people who visit your website and leave them either confused or misguided.
Ward Ricker
Thank you for your comments. We had several physicians review and approve the content.