When necessary, alternative methods of calculating the period
Even if a woman knows the start date of your last bleeding, but her menstrual cycle is characterized by great irregularity, based on the standard method of calculating the duration of pregnancy is impossible. Besides, it may happen that it took for my period light bleeding, occurring with the existing pregnancy. To more accurately determine the date of future delivery, and may even have to resort to less common ways of calculating the pregnancy.
The definition of the term ultrasound
Modern technology can greatly facilitate difficult at first glance task. Manufactured today devices of ultrasonic diagnostics allow up to 1 day to establish the age of a small embryo, but only in case if the pregnancy does not exceed 12 weeks. All the kids prior to this period grow equally, later on the size start to influence features of personal development.
The height of the uterine fundus
If to determine the exact period when ultrasound is not possible, you have to resort to more ancient methods, it is necessary to remember that these are approximate and depend on them should be more than careful.
One of such methods is the definition of height of standing of uterus day. Starting from 16 weeks, the doctor may palpate through the abdominal wall, and if it is, for example, reaches the navel, it is possible to say that the gestation is 22-24 weeks.
Even accurately calculated due date is not absolute and serves only for reference, because a normal pregnancy ranges from 38 to 42 weeks.
The least accurate criteria on which to define the term, are stirring. According to obstetric textbooks nulliparous women begin to feel the first tremors on the 20th week, the more experienced their fellow member at 17-18. But as practice shows, everything is so highly dependent on the sensitivity of women, sometimes even suspicion, the location of attachment of the fetus in the uterus and temperament of the child, some expectant mothers already at 14-15 weeks boasted the first "pinocchi", while others fall into a real panic due to the fact that, at 21-22 weeks of not feeling anything at all.
Sometimes when calculating the period of pregnancy can help date of conception, if known more or less accurately.
Which way is more precise
Therefore, if the monthly date is unknown, you should contact an experienced usesto, only in this case the pregnancy can be calculated more or less accurately. All other methods give more than an approximate version they should be considered only as an auxiliary method.