все отсюда http://baby2see.com/gender/external_geni
(к сожалению, не могу под кат убрать из-за таблицы)
External genital changes in Fetus development42 days (6 weeks) after fertilization, around week 8 of pregnancy
|6 week old embryo|| ||(Embryo size = 0.5 inch, 12 mm)|| |
- Buds of the arm
- Arc branchial
- Placenta membrane
- Genital tuber
- Site of the heart
- Bud of the leg
- Umbilical cord
At the sixth week the site of the genitals is a small bud, called the genital tuber.
Until the ninth week of fetus development, the embryonic reproductive apparatus is the same one for the two sexes.
[ Internal genital organs ]
The HOT topic on pregnancy forums around the world is...
The angle of the dangle topicQ. Can they tell the sex of baby at 12 week scan ?
A. At around 12 weeks a sonographer may make a 'best guess' as to the gender of baby from a scan, but this can, and will be, only a little better than 50/50.
Mouseover = Rotate image
The correct visualization of any fetal part depends on many factors such as fetal position, amount of amniotic fluid and thickness of the abdominal wall. The following images are not typical, as intermediate forms exist, establishing gender can sometimes be very difficult.Who has the bigger ?
How accurate are routine first trimester scans for fetal gender determination.
Ultrasound gender study - Objective study to assess the accuracy of fetal gender determination at a routine first trimester scan for detailed assessment of anatomy and nuchal thickness measurement.
In the study the angle of the genital tubercle was used to assign fetal gender. At 11 weeks there was an error rate of 50% and only 14 of every 100 was assigned correct male gender. In the male fetuses after 12 weeks, there was a significant increase in the angle of the genital tubercle from the horizontal. The accuracy of sex determination increased with gestation.
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| ||By the 20th week of pregnancy the external genitalia changes are done. On ultrasound, if your baby is cooperating and is positioned in a favorable way, his or her sex can be identified as early as the 16th to 18th week of your pregnancy. |
The male fetus may show a round bulbous area within the genital area which is the scrotum and penis. This sometimes can be seen on screen as an appearance similar to the profile of a small snail.
Of course, if your baby is 'hiding his stuff' (positioned in such a way as to prevent identification), it will make no difference how far along in your pregnancy you are -- you won't find out your baby's sex.
The correct visualization of any fetal part depends on many factors such as fetal position, amount of amniotic fluid and thickness of the abdominal wall.
3D scans can make it easier to see the gender of baby.
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| ||Most of the time the sonographer should be able to tell the sex of the baby by about 20 weeks. The correct visualization of any fetal part depends on many factors such as fetal position, amount of amniotic fluid and thickness of the abdominal wall.|
The absence of the penis must not be taken as sufficient evidence of the fetus being a girl. Using ultrasound the 3 lines sign which denotes the labia in the fetus is an indication of the female gender.
Ultrasound scans done in later pregnancy or 3D scans can make it easier to see the gender of a baby. The sonographer may not always get a good view of the private parts of the fetus for many reasons and therefore may not be able to give you an accurate answer.
Some sonographers are not allowed to tell you the gender, but may show the genital area on the screen and let you decide which sex your baby is.