Personal Pregnancy Calculator and Fetal Developmental Charting Wheel Developed expressly to facilitate due date calculations for the pregnant mother and explain what physical fetal changes to expect during the pregnancy term.  Base wheel: 5" diameter x .020". Top wheel: 3 7/8" diameter x .020" durable white vinyl plastic. A birth date calculator and fetal development indicator, this tool allows determination of a the approximate date for a baby's birth and tracks approximate weight and size of the developing fetus. OVERALL DIMENSIONS 5" DIAMETER

PRINCIPLE

Once a positive pregnancy is confirmed, the next immediate questions relate to an expected due date and the physical changes and biological symptoms one can expect during pregnancy. Pregnancy due dates are said to be 40 weeks long. The 40 week standard estimate was first developed by German Obstetrician Naegele in the 1800's (hence it is called "Naegele's Rule"). He declared that a woman's pregnancy should last 10 lunar months (or 280 days), being about 9 calendar months. However, because Naegele used the first day of the woman's last menstrual period as a definitive starting point on which to base his calculations, and further, that conception typically happens 2 weeks after this time (or two weeks before the woman's next period is due) a pregnancy is really only 38 weeks long (or 266 days), being about 8 ½ calendar months. Therefore, one week after conception, a woman is said to be 3 weeks pregnant. Today, most obgyn physicians and healthcare providers continue to use Naegele's rule as the preferred method to calculate a baby's due date.

Naegele based his calculation on a woman having a regular 28 day menstrual cycle. Therefore, if the mother has a regular 28 day cycle and the date of the first day of the last normal menstrual period is known, Naegele's rule would be used to calculate the baby's due date as follows: 9 months + 7 days after the first day of the last NORMAL menstrual period (or 280 days after this day). Since gestational development is not generally correlated to a woman's cycle after pregnancy commences, adjustments for irregular cycle days are usually not necessary.

USE

The Personal Pregnancy Calculator was developed to facilitate due date calculation automatically. The indicator arrow on the wheel is positioned on the first day of the last cycle. The expected due date is shown opposite the second indicator arrow. Additionally, normal symptoms and discomforts of pregnancy encountered in each month and a week-by-week fetal development and growth analysis are illustrated.

AVAILABILITY AND ORDERING

The Personal Pregnancy Calculator and Fetal Developmental Charting Tool is available in the sales units indicated below. Volume discounts are reflected in the unit price. For quantities exceeding the standard sales units, please contact our customer service department. Overall dimensions 5" diameter.

Description	Packaging	Sales Unit	Cost
Personal Pregnancy Calculator & Fetal Development Chart	Each	One (1) Each	$5.95
		Six (6) Each	$33.00
		Twelve (12) Each	$60.00
		Twenty Four (24) Each	$114.00
		Forty eight (48) Each	$216.00
		One Hundred (100) Each	$395.00
*If the order buttons are absent or inoperable, please use the pricing overview page to order.