Calculation of Gestation (SSW)

If the pregnancy test shows positive and also the blood test at the doctor’s Office has confirmed the pregnancy, it is sure: Wow, I’m pregnant!

But: In which week of pregnancy am I? And how to calculate the proper SSW?

The calculation of the week should be easy. A pregnancy lasts an average 38 weeks or 266 days from the fertilization of the egg to the birth of the baby. What is however rather complicated the thing: hardly anyone can the time of ovulation – and therefore the exact date of fertilization – in hindsight tell exactly. That is why doctors have considered a way out.

40 weeks of pregnancy until birth

Today is generally the practice to calculate the duration of pregnancy from the first day of the last menstrual period. In contrast to the ovulation, most women can quite precisely specify this day. If one assumes an average cycle length of 28 days, most women have her ovulate around the 14th cycle day. These first two weeks of the first day of the cycle (period), to ovulations are counted for convenience to pregnancy to the simplicity. Even if you were actually not pregnant during this time. According to calculation of doctors, a pregnancy lasts thus 40 weeks, or 280 days.

For most women, the period lack of is the first signs of a pregnancy. If you now perform a pregnancy test , you are probably already in the 5th week of pregnancy (SSW) or even more according to this calculation.

So, doctors calculate the current week of pregnancy

Once your gynaecologist has confirmed the pregnancy, he calculated the SSW and thus the age of your baby. Your cycle is regularly longer or shorter than 28 days, will he incorporated it into his calculation and correct SSW according to. More precisely determining the week of pregnancy, when to specify the dates of your ovulation, for example because you had led an ovulation test goes.

If the cycle is irregular or longer time no bleeding has occurred, the doctor estimates the age of the embryo on the basis of the stage of development, that it can validate using the ultrasound device.

What is the calculation of the SSW important?

Of course also the presumed confinement date of your baby can be determined with calculating the week of pregnancy. Stiffen up but please not too much on this date – only 4% of all children are actually born at the expected date. The precise calculation in the first place has meaning for your doctor so that he can check the age-appropriate development of your baby during pregnancy.

Determination of the SSW ultrasound

The first detailed ultrasound examination, which takes place between the ninth and twelfth week, again check the week of pregnancy your doctor and adjust if necessary. For the calculation of the length of the embryo is critical first and foremost. With the second ultrasound between the 19th and 22nd week, he can check his first calculation again. For this purpose, he misses the head diameter, the thigh bone, the chest and the length of the baby. For the first months of pregnancy, there are very reliable statistical values, on which he can orient. Using the computer of the ultrasonic device, he thus can calculate pretty accurately how old is the little earthlings.

The calculation in detail

If a pregnant woman proudly reported that it is 10 + 2 in the week, then she will not express the fact that that she has a soft spot for mathematical equations and gestation is currently in the 12th. Rather, it wants to provide information as accurately as possible. 10 + 2 simply means that it has completed the tenth week and brought two more days behind him. Consequently, it is now in the eleventh week of pregnancy.

Practical SSW calculator

By the way, much easier is our practical SSW calculator. Here you can calculate online, in which week of pregnancy (SSW) you are and learn about the dates should be perceived in the course of the pregnancy.