The first baby ultrasound appointment is certainly an exciting occasion for both parents and an opportunity for many early questions to be answered. Importantly the pregnancy can be confirmed and an early diagnosis of the general health of the baby can normally be provided. Also the presence of twins or other multiple conceptions can be quickly detected. However, by far the most common question obstetricians receive is regarding the gender of the baby. Whilst parents are certainly eager to hear that the baby is healthy, “Is my baby a boy or a girl?!” is still without doubt the question at the front of most mothers’ minds.
This article explores the methodology of ascertaining baby gender using ultrasound in the early stages of pregnancy, and also discusses the degree of accuracy and what mothers should expect.
How does the ultrasound identify baby gender?
As described in the previous post, ultrasound uses sound waves that are passed through the mother’s abdomen and return to the transducer where they are analyzed and portrayed as a real-time representation on the monitor display. The method of diagnosing baby gender is therefore a visual observation and assessment of the images returned. The medical professional conducting the scan will isolate the perineum (the genital region of the baby; i.e. the private parts!) and will assess the baby gender according to the form of the genitalia observed. The appearance of the ‘3 lines’ indicator, which represents formation of the female labia, is the strongest denotation mark identifying the baby gender as female. The image should consistently show three short parallel lines between the legs. Similarly, a boy can be identified by the dome-shaped protrusion of the testes and the cylindrical shape of the penis.
How soon can an ultrasound identify baby gender?
Ultrasounds taken at 16 to 20 weeks have a strong likelihood of being able to identify baby gender. Studies have shown, however, that baby gender can be ascertained via ultrasound as early as 11 weeks. Nevertheless, most doctors will recommend that parents wait until the 20-week mark before expecting a reliable assessment of baby gender to be made. A degree of patience is advised as every scan is different and there are a number of factors that can affect the quality of the diagnosis. Some doctors may be disinclined to offer an early diagnosis of baby gender until after a period of scans, and a growing number of practices avoid baby gender diagnosis altogether.
How accurately can an ultrasound identify baby gender?
As mentioned above, a pregnancy ultrasound scan relies on the quality of the image and the visibility of the genital area. There are several factors that may affect this:
Age of the pregnancy:
Up until the eighth week of pregnancy, male and female babies’ external genitalia are actually indecipherable. During 12 – 14 weeks they are still not fully formed but are recognizably male or female.
Position of the baby:
The baby may be aligned in such a way that a clear and unobstructed view of the genital area is difficult to attain.
Amount of liquid:
The presence of liquid improves the conduction of the sound waves and improves the clarity of the image produced. Low volumes of liquid are normal during early pregnancy and therefore ultrasounds taken during this period are likely to be of poorer clarity.
Thickness of the abdominal wall:
Abdominal wall thickness varies from woman to woman and normally will increase as pregnancy progresses. Fat and muscle will likely reduce the clarity of the ultrasound image.
Position of the placenta or umbilical cord:
The placenta or umbilical cord can obstruct the view of your baby’s genitalia. Both the umbilical cord and the placenta will likely move during your pregnancy and even during the ultrasound itself.
Any one of these factors could result in a pregnancy ultrasound being of insufficient clarity to accurately identify baby gender. In some extreme cases, a combination of repeatedly unfavorable conditions such as these over an extended period means baby gender still cannot be diagnosed even up to 28 weeks. Nevertheless, scientific tests studying the accuracy of ultrasounds at 12 weeks have reported levels of accuracy from 80 to 98%.
Conclusions
Ultrasound is an excellent and non-invasive baby gender predictor tool. However, remember that every scan, and every pregnancy is different. Although it is highly likely that an ultrasound at after 20 weeks will identify your baby’s gender, there is no set-in-stone guarantee. Also remember that the analysis of an ultrasound scan is mostly subjective. Even if your doctor is fairly confident of the gender diagnosis, they may feel inclined to withhold a definitive opinion until more scans have been conducted over the following weeks. It is recommended that you ask plenty of questions during the scan and ask your doctor to point out and describe all the features shown by the scan. If you are lucky to have a clear scan then you will likely be able to assess baby gender yourself without the help of the doctor. Remember that you can always arrange for a repeat scan if the conditions are unfavorable, and have the option to seek a second opinion if you are not satisfied with the diagnosis. If you are having an early ultrasound before 12 weeks, then adjust your expectations accordingly as scans tend to be less clear. Similarly, if you are less than 12 weeks into your pregnancy and wish to know the gender, you want to consider other baby gender predictor methods.
March 26th, 2010 at 3:33 pm
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May 2nd, 2010 at 9:14 am
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