Doppler Ultrasonography The fetal heart can be heard using Doppler ultrasound by 10 to 12 weeks in most patients . Savitz DA, Terry JW Jr, Dole N, Thorp JM Jr, Siega-Riz AM, Herring AH.
Chorionic gonadotropin secretion by human embryos in vitro.
Time of implantation of the conceptus and loss of pregnancy.
They are missing the point: cults are a family problem, since a cult is an artificial family that seeks to supercede your own and ultimately destroy it.
Determining the Date of Conception Because the human egg is capable of fertilization for only 12 to 24 hours after ovulation the date of ovulation may be taken as being the date of conception.
The very nature of being unchallengeable and of wanting an authority to tell you what is right for you, or what to do, is a deep part of how the world works.
In a static world, where change is either slow or not valued at all, as it has been throughout much of human history, authoritarianism although it has caused human suffering has also been the fast way to get things done.
So I would say authoritarianism itself as a mode of information transference is essentially unhealthy for these times.
People tend to think of cults as an information problem, a doctrinal problem.
The American College of Obstetricians and Gynecologists recommends that ultrasound-established dates should take preference over menstrual dates when the discrepancy between ultrasound dating and LMP is "Because of the risk of redating a small fetus that may be growth restricted, management decisions based on third-trimester ultrasonography alone are especially problematic; they need to be guided by careful consideration of the entire clinical picture and may require closer surveillance, including repeat ultrasonography to ensure appropriate interval growth." . Birth weight from pregnancies dated by ultrasonography in a multicultural British population.
Other Methods For Estimating the Gestational Age Clinical Examination A pelvic examination supported by good menstrual records in the first trimester has been reported to be a reliable method for dating of pregnancy .
Observed Gestational Age at Delivery The table below shows the average age of infants delivered in the United States according to the number of fetuses being carried (plurality) . Savitz DA, Terry Jr JW, Dole N, et al: Comparison of pregnancy dating by last menstrual period, ultrasound scanning, and their combination.