Pregnancy is undoubtedly one of the scariest, most nerve-wracking as well as the happiest period of your life. No other phase or period is going to be as diverse in both situations and emotions as pregnancy. There are countless things that you are aware of, and yet there are gazillion things you are unaware of. It is important to sit with your doctor for a few sessions and gain a thorough, first-hand knowledge of pregnancy, how it affects both the mother and the baby and in what ways it changes family dynamics. There are certain things that need to be known, such as the conception date, gestational date, due date and other factors associated with them. In this article, we will discuss the methods used for calculating these specific dates. Read on to find out everything that you need to know about these things.
In this article:
Gestational Age
Calculating Gestational Age
Calculating Conception Date
Calculating Due Date
Difficulties in Determining the Gestational Age
A Guide for Calculating Conception
Gestational Age
Gestational age, also known as the age of the baby, is the age that is usually calculated from the first day of the expectant mother’s last menstrual cycle. Since the exact date of conception is almost never known or calculated due to lack of precision, the first day of the last menstrual period is used to measure how old the baby is.
Calculating Gestational Age
Last Menstrual Period
If the pregnant woman has had a medical history of a regular period pattern and is aware of the first day of her last menstrual period, then the gestational age of the baby can always be calculated from this date itself. Gestational age is always calculated from the first day of the expectant mother’s last menstrual period and not from the date of conception. That is a misconception that should always be cleared as soon as possible.
Ultrasound
The conception date of the unborn baby can be measured as early as five-six weeks after the expectant mother’s last menstrual period. Measuring conception date of the baby using ultrasound is the most accurate method used in early pregnancy. It becomes less accurate in the later stages of pregnancy. The best time to estimate the gestational age of the unborn baby using ultrasound is between the 8th and 18th weeks of the period of pregnancy. The most accurate way to determine the gestational age of the unborn baby is using the first day of the woman’s last menstrual period and then confirming this gestational age with the measurement from an ultrasound exam in early pregnancy.
Calculating Conception Date
In a Typical Pregnancy
For a pregnant woman with a medical history of the regular period pattern, the process of conception typically occurs about three weeks days after the first day of the last period. Most women are unaware of the exact date of conception because it can be challenging to determine and know exactly when the process of ovulation occurs. Thus, their conception date is merely an estimate that is mostly based on the first day of their last period. This is the usual scenario in a typical pregnancy.
Special Cases
Women, who undergo special procedures for getting pregnant, such as artificial insemination or in vitro fertilization (IVF), typically know the exact date of conception. This is because this process is carried out in a lab and therefore, it is easier to determine the date of conception for these women.
Calculating Due Date
Estimated Due Date
Based on the last menstrual period of the expectant mother, the estimated due date, that is when the baby is supposed to be born is mostly approximately 40 weeks from the first day of the last period. This is always just an estimate since only about few of the babies are born on their estimated due date. Every woman’s pregnancy is different, so nobody can really expect a baby to be born on the exact due date specified.
Difficulties in Determining the Gestational Age
Last Menstrual Period
For pregnant women having 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. In these cases, an ultrasound exam is often required to determine gestational age of the baby.
Baby’s Growth
In certain cases, it is difficult to determine the gestational age because the baby is unusually large or small and therefore has abnormal growth. Also, in some cases, the size of the uterus in early pregnancy or the height of the uterus in later pregnancy does not match the first day of the last menstrual period. In these cases as well, it is difficult to obtain an accurate gestational age.
Therefore, to conclude, with these methods described in details, we hope you have a fair idea as to how to calculate the conception date. In case you are unable to do so, always contact your doctor.
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641465/
