When is gestational age calculated from

In these cases as well, it is difficult to obtain an accurate gestational age. Calculating Conception. Use our Pregnancy Calculator to calculate these dates for you. Calculating Gestational Age Last Menstrual Period If the mother has a regular period and knows the first day of her last menstrual period, gestational age can be calculated from this date.

Calculating Conception Date In a Typical Pregnancy For a woman with a regular period, conception typically occurs about days after the first day of the last period. Special Cases Women who undergo special procedures, such as artificial insemination or in vitro fertilization , typically know the exact date of conception. Calculating Due Date: Estimated Due Date Based on the last menstrual period, the estimated due date is 40 weeks from the first day of the period. Difficulties in Determining the Gestational Age Last Menstrual Period For women who have irregular menstrual periods or women who cannot remember the first day of their last menstrual period, it can be difficult to determine gestational age using this method.

Want to Know More? Can I get pregnant if…? Share this post:. Share on facebook Facebook. Share on twitter Twitter. The calculation is done in this way because although you may not yet be pregnant, it is very difficult to define exactly when fertilization occurred, because sperm cells can survive up to 7 days in the woman's body before fertilizing the egg and actually initiating a pregnancy.

According to the Ministry of Health determining the gestational age, converting the weeks into months, should be worked out as follows:. Usually the pregnancy lasts 40 weeks, but the baby can be born between 39 and 41 weeks without problems. However, if labor does not start spontaneously until the week mark, the doctor may choose to induce labor with oxytocin to the vein.

To calculate the probable due date, which should be around 40 weeks after the LDM, it is necessary to add 7 days to the LDM, then count 3 months back and then add one year. For example, if the LDM was March 11, , by adding 7 days, the result is March 18, , and then subtract 3 months which means December 18, and then add 1 year.

So, in this case, the probable due date is December 18, Suggested protocols Algorithm. Disease Select Specialty Select Chief Complaint Select Organ System Select Log In. Email Address. Password Show. Or create a new account it's free. Forgot Password? Sign In Required. To save favorites, you must log in. Creating an account is free, easy, and takes about 60 seconds.

Log In Create Account. The principal investigators of the study request that you use the official version of the modified score here.