Fetal sex determination is usually done with ultrasound at 16 weeks or later.
If you choose to undergo procedures such as CVS (chorionic villi sampling) or
amniocentesis, you can get your baby's sex determined as well.
See, e.g., http://www.libertywomenshealth.com/10.html:
"Sex determination of the fetus can be done accurately by 16-18 weeks by expert
ultrasound at our office in most cases, and as early as 14 weeks in some cases.
This can sometimes be helpful in ruling in or out some diseases that are sex-
linked. The sex of the fetus is also accurately determined if a patient
undergoes a CVS (chorionic villi sampling) at 10-11 weeks or an amniocentesis
at 15-16 weeks."
According to some studies, it may be too early to try to determine your baby's
sex even at 16 months. A lot depends on the technician's skill and the position
your baby is in at the moment.
From
http://www.parentsplace.com/expert/midwife/qas/0,10338,239702_115332,00.html:
"Even though studies are now reporting 100 percent accuracy in determining
fetal gender between 11 to 16 weeks of gestation, in the average clinic
situation, fetal gender identification is often not undertaken until at least
16 weeks, and is often not reliable until 20 to 24 weeks -- and this is when
the baby cooperates fully!
In a study by Whitlow, published in Ultrasound in Obstetrics & Gynecology, a
sample of 524 women underwent a detailed assessment of fetal anatomy at 11 to
14 weeks of gestation by means of transabdominal sonography and transvaginal
sonography (26 percent). Fetal gender was identified and was confirmed at
birth. The overall success of correctly assigning fetal gender increased with
gestational age. At 11 weeks predictions were correct 46 percent of the time,
at 12 weeks 75 percent, at 13 weeks 79 percent and at 14 weeks a 90 percent
success rate was reached."
Koala Labs claim to determine fetal sex reliably as early as the tenth week of
gestation.
From http://members.aol.com/jdskoala/frame_frame.htm:
"Koala Labs uses a patented FASA scan technology that is accurate and reliable
as early as the tenth week of fetal development. Sonogram results are available
immediately. According to an article in the New England Journal of Medicine
(October 20, 1983), the technique of using sonogram images to determine whether
a unborn baby is a boy or a girl was originally developed in conjunction with
genetic amniocentesis. Using ultrasound scanning to observe the sex/gender of
an unborn baby, however, is completely accurate as a stand-alone technique."
There's also a brand new procedure that involves measuring a certain hormone in
your blood or urine.
From
http://www.clickondetroit.com/det/health/lilasgoodhealth/stories/lilasgoodhealth
-121819620020201-210225.html:
"Ultrasounds are often performed during the second trimester of pregnancy, but
scientists hope that in the future a blood or urine test may give parents an
indication of whether they will have a boy or a girl.
Genetic researchers at the Tel Aviv Medical Center found that a hormone called
MSHCG triggers a positive pregnancy test. That hormone is much higher if a
woman is carrying a girl than if she's having a boy, researchers said. And that
difference can be detected 16 days after conception."
There are some other methods that were commonly used before ultrasound was
developed, but they don't seem to be accurate.
From http://www.cma.ca/cmaj/vol-161/issue-12/1525.htm:
"Many family physicians have been asked time and time again about the accuracy
of certain "old wive's tales" for predicting the sex of the fetus. Among the
more popular "tales" inquired about are the fetal heart rate test, the Chinese
calendar test and the Draino test." [This goes on to show why those tests are
unreliable.]
Also, you can try a Google search for "fetus OR fetal sex OR gender determine
OR determination OR identification", and specific searches for "ultrasound
fetal sex", "MSHCG fetal sex", and "early pregnancy fetal sex determination",
to find more answers. |