It depends on the length of pregnancy, what we can investigate with ultrasound.
Generally speaking, in terms of: the fetal position, size, fetal movements, heart activity and breathing movements. The fetal head, heart, lungs, gastrointestinal, arms and legs. Also be assessed placenta size and appearance, as well as whether it sits in customize spacing from the cervix. Furthermore, looking after, whether there is a normal amount of amniotic fluid – either too little or too much.
The first third of pregnancy
In the first third of pregnancy can be approximately 4 weeks after the last menstrual period see the first signs of pregnancy. But first from 6 weeks of pregnancy length, one can with certainty determine whether pregnancy sits inside or outside the womb. From 6 weeks of pregnancy length, one can see the embryonic plant (embryo) with heart action. The size of the embryo is used to judge how the pregnancy When the fetus develops will be visible, use main-rumpe length (Crown-Rump Length CRL) to judge the length of pregnancy.
Multiple pregnancies can be seen early on, and this is important because you can determine how much prejudice there is between the twins. The number of membranes between the twins has implications for how many times the pregnant must ultrasound scan in pregnancy. Who is most at risk, if there is no (monoamniotiske) or only one film between the twins (mono koriske).
The second and third part of pregnancy
In the second and third part of pregnancy fetal growth can be assessed by measuring the length of the head, both across (biparietal diameter ~ BPD) and lengthwise (occipito-frontal diameter ~ OFD), stomach scope and length of the thigh bone. All these objectives are translated using a computer program to a calculated fetus weight.
The gestational age (length of pregnancy) is determined by measuring crown-rump length by nuchal translucency scan between weeks 11 and 14. Between 14 and 22 weeks pregnancy length is determined by measuring the main scope. After 22 weeks, it is difficult to use ultrasound to determine the due date.
Ultrasound is very suitable to examine the placenta location. By means of scanning in week 18 to 20 will 5-10% have a placenta, which lies close to the inner opening of the cervix (placenta ~ placenta previa under discussion), while only 0.5% want “under discussion” placenta at birth. If the placenta is under discussion at birth, birth by caesarean section.