Year: 2018


Perhaps, having done the pregnancy hCG strip test, you have confirmed that you are pregnant, or you got to know after a consultation with your doctor, the next big question that comes to mind is ‘when am I due?’ While an answer termed an estimated due date is usually provided by a gynaecologist or your general medical practitioner, it is quite interesting to know that computer programs, often referred to as ‘pregnancy calculator’, ‘pregnancy confirm calculator’, or ‘pregnancy due date calculator’ have been developed to answer that question, in such a way that, the answer produced by such computer program matches the one provided by your gynaecologist.

However, the way such computer programs could predict the due date that matches the ‘estimated due date’ predicted by a gynaecologist therefore leaves one in awe. It should however be noted that the mechanism or basic principle on which such computer program is based, is quite similar to the basic medical principle employed by your doctor in providing an estimated due date.

Here is how it works!

The basic medical principle on which a pregnancy calculator works is such that, having supplied the date of your last menstrual period (LMP), three months is subtracted from the first day of your last menstrual period, then seven (7) days are added to it, this gives the ‘estimated due date’. Therefore, in programming, the programmer programs such that the program requests for the date of the last menstrual period and subtracts three months, followed by an addition of seven days, to display an ‘estimated due date’.

Take for instance, if your last menstrual period began on April 10th. On entering this information into the Last Menstrual Period (LMP) field on request of the computer program, the program goes on to subtract three months from the supplied date, which gives January 10th, followed by an addition of seven days, which eventually gives January 17th as the estimated due date (displayed instantly on the screen or sent to the email you supplied).

However, it should be noted that more often than not, the estimated due date calculated does not always turn out to be the date of delivery, as the actual delivery could take place a week or two before or after the estimated due date. This is because; the gestation period lasts from about 38 weeks to 40 weeks, which as such, obscures the possibility of an accurate date of delivery prediction.

Also, this system of predicting the due date, works better for people with a regular menstrual cycle and those who noted the date the last menstrual period (LMP) started. Therefore, with a knowledge of how the pregnancy calculator works, you would find it easier to either calculate your estimated due date or understand the principle your gynaecologist or general medical practitioner has employed in predicting the estimated due date. If however, you did not notice the start of your Last Menstrual Period (LMP), due to an irregular menstrual cycle, your general medical practitioner or gynaecologist would employ other methods to detect the stage of pregnancy you are in and the number of weeks you have been pregnant, such test include: Ultrasound scan, measurement of the height of your fundus and detection of the first fetal heartbeat.