Determining a baby's sex from an ultrasound relies on identifying specific anatomical features. A trained professional can accurately determine sex by observing markers such as the formation of labia (female) or scrotum (male).
Ultrasound Techniques for Sex Determination
Several methods are used during an ultrasound to determine the sex of a baby:
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Genital Visualization: This is the most reliable method. At around 18-20 weeks, the ultrasound can clearly visualize the external genitalia, allowing for the identification of a penis or clitoris and labia. [Identifying the foetal genitalia is one aspect of interpreting ultrasound images that allows parents to learn their baby's gender. By looking for certain markers, such as labia or scrotum formation, professionals can accurately identify whether your baby is male or female.]
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Nub Theory (Less Reliable): Some believe the angle of the genital tubercle (nub) at an earlier scan (around 12 weeks) can predict the sex. An upward-pointing nub is sometimes associated with a boy, and a downward-pointing nub with a girl. However, this method is not considered reliable. [However, there isn't much evidence that nub theory is reliable or accurate.] [If it points horizontally then it is likely to be a girl. We can be 95% accurate at this early stage of pregnancy. Nub points up BOY]
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Three Lines on Ultrasound (Female Indicator): The presence of three distinct lines in the genital area during an ultrasound can sometimes indicate a female fetus. These lines represent the labia majora, the clitoris, and the labia minora. [If they see three distinct lines in the genital area, it's a sign that the baby is female. These lines represent the labia majora, the clitoris,...]
Important Note: While some methods like nub theory exist, they are not scientifically validated. The most reliable method for determining the sex of a baby through ultrasound is through visualization of the external genitalia at around 18-20 weeks gestation by a qualified medical professional.
Other Methods and Myths
Several other methods are commonly circulated, but they are generally not reliable:
- Skull Theory: This method attempts to predict sex based on the shape of the baby's skull in an ultrasound; it is not scientifically supported.
- Heart Rate: Some believe heart rate can predict sex; this is also not a scientifically reliable indicator.
- Pregnancy Symptoms: Many believe pregnancy symptoms can predict sex; however, scientific research does not support this belief.
