You can read more about my excitement here:
I am happy to say that a French study confirms not diagnosing a blighted ovum before the gestational sac reaches 25mm. For women with a tilted uterus, that puts them at about nine weeks.
"First trimester nonviable pregnancy is established with gestational sac mean diameter and embryo crown-rump length. Mean sac diameter≥25mm without embryo (LE2) or embryo crown-rump length≥7mm without heartbeat (LE2) by transvaginal sonography allows to diagnose pregnancy failure."
In other words, if your gestational sac is growing, your doctor should not even be suggesting a blighted ovum until the sac is 25mm. Some guidelines recommend waiting an additional week after you reach 25mm to just be sure. Of course, this is if there are no serious complications (i.e. ectopic, partial mole, etc...).
Why do I feel so strongly about this? My gestational sac at 7 weeks 5 days measured 21.5mm and still looked empty. I turned down the D&C for the second time. At 8 weeks 5 days, my sac measured 28.5mm and we saw my little one with a very strong heartbeat. Since I shared my story, many more women have had similar stories.
Your doctor really should not be diagnosing a blighted ovum if your gestational sac is still less than 25mm and growing. If he or she is, might be time to find a new doctor.