From that day, 40-weeks of pregnancy is officially counted, and your doc or midwife busts out the red pen and marks your due date on the calendar. However, many pregnancies are confirmed by a Doppler heartbeat monitor, not an ultrasound.
If this was you, that could be why your doctor’s original timing was off.
A recent article explained that doctors are now going to be using first trimester ultrasounds to determine due date in the majority of pregnancies.
Earlier this week the American College of Obstetricians and Gynecologists (ACOG) met with the American Institute of Ultrasound in Medicine and the Society for Maternal-Fetal Medicine to set new guidelines for due date determination. James Goldberg, vice chair of ACOG’s committee on obstetric practice, stated, “Some studies suggest up to 40 percent of pregnancies would have dates changed based on [a] first trimester ultrasound.” This difference is because most women do not know the day they conceive and the 40 week rule-of-thumb is based on a 28 day cycle, which is not always a good guideline for women with irregular or longer cycles.
Health-care providers define the stage or length of pregnancy differently than many people might think. Logically, one might imagine we represent a pregnancy by how much time has elapsed since conception.
If the difference between the two is less than a week apart, she’ll generally go with the date calculated from your last period.An ultrasound can help you determine how far along you are in your pregnancy.Before you consider abortion or seek an abortion clinic, it is important to know how many weeks pregnant you are (the gestational age).The length of this is approximately the size of your uterus and closely correlates to how far along you are.She may notice that the size of your uterus doesn’t synch up with the standard growth charts (you measure big).When people discuss how far along in pregnancy someone is, they tend to do so in general terms: “She’s in the first trimester” or “She’s four months along.” However, many people have only a vague idea of what those phrases really mean.