First trimester identification of fetal sex by ultrasound

  • Maternal-Fetal Medicine
  • Published: 03 May 2023

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  • Emma C. Schaefer   ORCID: orcid.org/0000-0003-3967-1752 1 ,
  • David S. McKenna 1 &
  • Jiri D. Sonek 1  

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The hypothesis was fetal sex determination by ultrasound at 11–14 weeks’ gestation has sufficient accuracy to be clinically relevant.

Fetal sex assessment by transabdominal ultrasound was performed in 567 fetuses at 11–14 weeks’ gestation (CRL: 45–84 mm). A mid-sagittal view of the genital region was obtained. The angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was measured. The fetus was assigned male sex if the angle was > 30°, and female sex if the genital tubercle was parallel or convergent (< 10°). At an intermediate angle of 10–30°, the sex was not assigned. The results were divided into three categories based on gestational age: 11 + 2 to 12 + 1, 12 + 2 to 13 + 1, and 13 + 2 to 14 + 1 weeks’ gestation. To establish its accuracy, the first trimester fetal sex determination was compared to fetal sex determined on a mid-second trimester ultrasound.

Sex assignment was successful in 534/683 (78%) of the cases. The overall accuracy of fetal sex assignment across all gestational ages studied was 94.4%. It was 88.3%, 94.7%, and 98.6% at 11 + 2 to 12 + 1, 12 + 2 to 13 + 1, and 13 + 2 to 14 + 1 weeks’ gestation, respectively.

Prenatal sex assignment at the time of first trimester ultrasound screening has a high accuracy rate. The accuracy improved with increasing gestational age, which suggests that if clinically important decisions, such as chorionic villus sampling, are to be made based on fetal sex, they should be delayed until the latter part of the first trimester.

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fetal gender assignment by first trimester ultrasound

Data availability

The data that support the findings of this study are not openly available due to reasons of sensitivity and are available from the corresponding author upon reasonable request. Data are located in controlled access data storage at Miami Valley Hospital Department of Maternal-Fetal Medicine Ultrasound and Genetics.

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The authors declare that no funds, grants, or other support was received during the preparation of this manuscript. The authors have no relevant financial or non-financial interests to disclose.

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All authors contributed to the study conception and design. Data collection and analysis were performed by Emma C Schaefer. The first draft of the manuscript was written by Emma C Schaefer and all authors commented on previous versions of the manuscript. DSM: protocol/project development, manuscript editing. JDS: manuscript editing. All authors read and approved the final manuscript.

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Schaefer, E.C., McKenna, D.S. & Sonek, J.D. First trimester identification of fetal sex by ultrasound. Arch Gynecol Obstet (2023). https://doi.org/10.1007/s00404-023-07046-0

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Ultrasound in Obstetrics & Gynecology : the Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology , 01 Jun 2006 , 27(6): 619-621 https://doi.org/10.1002/uog.2674   PMID: 16493625 

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Fetal sex assignment by first trimester ultrasound: a Tunisian experience

Affiliation.

  • 1 Department A of Gynecology and Obstetrics, Tunisian Maternity and Neonatology Center, Rabta, 1007 Tunis, Tunisia.
  • PMID: 19813214
  • DOI: 10.1002/pd.2374

Objective: To assess the feasibility and accuracy of fetal sex identification during the first trimester ultrasound exam.

Methods: A prospective study was carried out on 312 fetuses at 11-14 weeks' gestation. The genital region was examined by transabdominal ultrasound. The angle of the genital tubercle to a horizontal line through the lumbosacral skin was measured. Fetal gender was assigned as male if this angle was > 30 degrees and female when it was < 10 degrees .

Results: Sex assignment was feasible in 89.7% and accurate in 85.7% of fetuses. Accuracy was similar in males as in females (87.9% vs 83.3%; NS). However, accuracy increased significantly during the gestational age period in male (Chi-square for trend P = 0.03) but not in female (P = 0.41) fetuses. Compared with singletons, presence of multiple fetuses (n = 12) did not influence feasibility or accuracy (89.2% vs 96% and 85.6% vs 86.4% respectively). In male fetuses, there was a significant increase in the angle of the genital tubercle with increasing crown-rump length(CRL) (r = 0.667; p = 0.025), while in females the angle did not significantly change with increasing gestation.

Conclusion: Sonographic first trimester sex assignment is highly feasible and accurate.

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  • Feasibility Studies
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  • Sex Determination Analysis / methods*
  • Ultrasonography, Prenatal / methods*

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The ultrasound identification of fetal gender at the gestational age of 11–12 weeks

Farideh gharekhanloo.

1 Department of Radiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran

Introduction:

The early prenatal identification of fetal gender is of great importance. Accurate prenatal identification is currently only possible through invasive procedures. The present study was conducted to determine the accuracy and sensitivity of ultrasound fetal gender identification.

Materials and Methods:

The present cross-sectional study was conducted on 150 women in their 11 th and 12 th weeks of pregnancy in Hamadan in 2014. Ultrasound imaging performed in the 11 th and 12 th weeks of pregnancy for fetal gender identification identified the fetus either as a girl, a boy, or as a “gender not assigned.” Frequency, sensitivity, specificity, positive and negative predictive values, and accuracy of the gender identification was assessed using SPSS version 20. The significant level was 0.05 in all analyses.

Of the total of 150 women, the gender was identified as female in 32 (21.3%), as male in 65 (43.3%), and not assigned in 53 (35.3%); overall, gender identification was made in 64.6% of the cases. A total of 57 male fetuses were correctly identified as boys, and 8 female fetuses were wrongly identified as boys. As for the female fetuses, 31 were correctly identified as girls, and 1 was wrongly identified as a boy. The positive predictive value for the ultrasound imaging gender identification was 87.6% for the male fetuses and 96.8% for the female fetuses.

Conclusion:

The present study had a much higher gender identification accuracy compared to other studies. The final success of fetal gender identification was about 91% in the 11 th and 12 th weeks of pregnancy.

Introduction

The early prenatal identification of fetal gender is of great importance in the management of pregnancy in families at risk for certain inherited diseases. Accurate prenatal identification is currently only possible through invasive procedures and chorionic villus sampling (CVS).[ 1 , 2 , 3 ] Occasionally, CVS is difficult to perform, posing a 1%–5% threat of pregnancy loss.[ 2 ] The fetal gender can be identified even in the first trimester of pregnancy from the 11 th -week onward through observing the direction of the genital tubercle and sagittal sign. A downward tubercle indicates a female fetus and an upward tubercle a male fetus.[ 3 , 4 ] If the examination of the midline sagittal view of the genital area shows a caudal notch, the fetus is female, and if it shows a cranial notch, then the fetus is male.[ 5 ] In the second and third trimesters of pregnancy, ultrasound imaging scans the genital anatomy of the fetus to identify its gender. In the early studies conducted on the use of ultrasound results for identifying the fetal gender, a male fetus was demonstrated by the presence of a scrotum and a penis, and a female fetus by the absence of these organs.[ 6 ]

With technological advances, seeing the vulva, clitoris, and labia are taken to indicate a female fetus, whereas seeing the scrotum, penis, testicles, and raphe indicate a male fetus. Seeing the internal pelvic structure of the fetus, including the uterus and ovary, is also used to help identify the fetal gender.

There is a substantial chance of getting a false-negative diagnosis if the ultrasound imaging for fetal gender identification has been performed in the first trimester of pregnancy.[ 3 , 7 ] However, research suggests a better sensitivity of ultrasound imaging for fetal gender identification performed in the second trimester of pregnancy.[ 8 ]

The sensitivity of gender identification measures depends on the operator, machine, and habitus involved, and it increases with the radiologist's experience and if ultrasound imaging is performed using the high-resolution machine.[ 3 ] A false fetal gender identification has adverse psychological effects on the family.[ 3 ] Specialists are therefore constantly seeking to make accurate fetal gender identification in the first trimester of pregnancy. The present study was conducted to determine the accuracy and sensitivity of ultrasound fetal gender identification in Hamadan.

Materials and Methods

The present cross-sectional study was conducted progressively on 150 women in their 11 th and 12 th weeks of pregnancy visiting private clinics in Hamadan for ultrasound fetal gender identification in 2014. Ultrasound imaging performed in the 11 th and 12 th weeks of pregnancy for fetal gender identification identified the fetus either as a girl, a boy, or as a “gender not assigned.”

Some patients visited during their second or third trimesters of pregnancy to confirm their fetal gender and register the ultimate fetal gender identified. In patients who did not visit during their second or third trimesters of pregnancy, the ultimate fetal gender identification was confirmed over the phone.

The ultrasound imaging device used was GE Voluson E6. Ultrasound imaging was performed by a radiologist; the genital region was examined in a mid-sagittal plane, and the fetal gender was assigned as male if the angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was >30° and female when the genital tubercle was parallel or convergent (<30°) to the horizontal line.

The data obtained were analyzed in SPSS 20 (SPSS, Chicago, IL, USA). The descriptive analysis of the data was conducted through assessing the frequency, sensitivity, specificity, positive and negative predictive values, and accuracy of the gender identified. The researchers used Chi-square test, Fisher's exact test, and t -test with a significance level of 0.05 to identify any significant differences between the data.

Ultrasound imaging was performed in 150 pregnant women, 51 (34%) of whom were in their 11 th week of pregnancy and 99 (66%) in their 12 th week. The youngest female fetus whose gender was correctly identified was 11-week-old, and the youngest male fetus whose gender was correctly identified was 11 weeks and 1 day old. The correct identification of gender was not related to the fetal gender (Fisher's exact test, P = 0.264).

Gestational age was significantly higher in cases where fetal gender identification could be made compared to in cases where the gender was not assigned (85.9 ± 3.3 days vs. 83.7 ± 3.9 days and P = 0.001). Of the total of 150 women who underwent ultrasound imaging in the 11 th and 12 th weeks of pregnancy, the gender was identified as female in 32 (21.3%), as male in 65 (43.3%), and not assigned in 53 (35.3%); overall, gender identification was made in 64.6% of the cases. As presented in Table 1 , in the 11 th week of pregnancy, gender identification was made in 23 (45.1%) cases, and in the 12 th week, in 74 (74.7%) cases. In the 11 th and 12 th weeks of pregnancy, a correct fetal gender identification was made in 31.32 (96.9%) of the baby girls and in 57.65 (87.7%) of the baby boys.

Fetal gender identification in relation to gestational age

An external file that holds a picture, illustration, etc.
Object name is JFMPC-7-210-g001.jpg

A total of 57 male fetuses were correctly identified as boys and 8 female fetuses were wrongly identified as boys. As for the female fetuses, 31 were correctly identified as girls, and 1 was wrongly identified as a boy [ Table 2 ].

Binary classification tests for the ultrasound identification of male and female genders

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Object name is JFMPC-7-210-g002.jpg

The positive predictive value for the ultrasound imaging gender identification was 87.6% for the male fetuses and 96.8% for the female fetuses. That is to say, reporting a male gender in the ultrasound imaging performed in the 11 th or 12 th weeks of pregnancy is likely to be 87.6% correct and reporting a female gender is likely to be 96.8% correct. Overall, ultrasound gender identification showed a high sensitivity, specificity, and accuracy [ Table 3 ].

Binary classification tests for ultrasonic detection of male and female sexes, respectively

An external file that holds a picture, illustration, etc.
Object name is JFMPC-7-210-g003.jpg

Discussion and Conclusion

The final success of fetal gender identification was about 91% in the 11 th and 12 th weeks of pregnancy. When gestational age increases, the possibility of gender identification becomes larger in percentage. Operator's skills had no significant effects on gender identification in either the baby girls or boys. The results of the present study were consistent with the results of other studies in terms of the effectiveness of an increased gestational age and the ineffectiveness of gender in the correct identification of fetal gender.[ 9 ]

The present study had a much higher gender identification accuracy compared to Whitlow's study (66%), which might be attributed to the new devices' better resolutions or the operators' skills. A study conducted by Hsiao et al .[ 10 ] between the 11 th week of pregnancy and the 13 th week plus 6 days reported an overall ultrasound accuracy of 91.8%, which is almost consistent with the results of the present study. Since, in the present study, ultrasound imaging was performed in the 11 th and 12 th weeks of pregnancy, the overall accuracy obtained was very favorable (90.7%). Ultrasound accuracy was 91.3% in the 11 th week of pregnancy and 90.5% in the 12 th week, compared to the 71.9% and 91.9% accuracy levels obtained for Hsiao's study. Compared to Hsiao's study, the ultrasound identification accuracy obtained in the present study was significantly higher in the 11 th week of pregnancy.

In 2009, Whitlow and Efrat published the very first articles about fetal gender identification in the first trimester of pregnancy.[ 9 ] Whitlow used a combination of transverse and sagittal view planes, whereas Efrat used a mid-sagittal plane to measure the genital tubercle angle with a horizontal line drawn on the lumbosacral surface. The results obtained by Whitlow et al ., Efrat, and Hsiao (who used transverse and mid-sagittal planes in 2008) showed an ultrasound fetal gender identification accuracy of 78% (35/46), 70.3% (26/37), and 71.9% (41/57) in the 11 th week of pregnancy, respectively, if taking into account only cases, in which the gender has been assigned.[ 9 ] The accuracies obtained were significantly lower than the accuracy obtained for the present study, which was 21/23 (91.3%). If all the women who underwent ultrasound imaging are taken into account regardless of the assigning or nonassigning of their fetal gender, the accuracies obtained for the cited studies will be 46% (35/76), 65% (26/40), and 42.7% (41/96), respectively, which is then comparable to the overall ultrasound accuracy obtained in the present study, that is, 45.1% (21/51).

The accuracy obtained on the 12 th week of pregnancy was 90.5% (67/74) in the present study if counting only the cases where the gender has been assigned; however, if also taking into account the cases, in which the fetal gender has not been assigned, the accuracy is 67.7% (67/99), which is comparable to the accuracies obtained for other studies: 86% (123/143), 92.8% (77/83), and 92% (195/212).[ 11 , 12 ] Compared to the previous studies, the present study found no significant increase in fetal gender identification accuracy in the 12 th week compared to in the 11 th week.

Overall, various factors can affect the correct identification of fetal gender in the first trimester of pregnancy. First, the operator's skills, which depends on his or her training; second, the ultrasound imaging device's resolution (a transvaginal ultrasound provides a better resolution than a transabdominal ultrasound); third, certain maternal factors can affect the results, such as bowel gas induced shadowing of the fetus or maternal obesity; and fourth, the fetal position in the womb, which can be in different forms, including the fetal legs being crossed, umbilical cord being between the fetus' legs, fetal hyperactivity, and an unfavorable fetal position.[ 12 ]

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Post-Roe v. Wade, more patients rely on early prenatal testing as states toughen abortion laws

FILE - An operating room technician performs an ultrasound on a patient at Hope Medical Group for Women in Shreveport, La., on July 6, 2022. Doctors in states with strict abortion restrictions say an increasing number of pregnant women are seeking early prenatal testing, hoping to detect serious problems while they still have time to choose whether to continue the pregnancy. (AP Photo/Ted Jackson, File)

FILE - An operating room technician performs an ultrasound on a patient at Hope Medical Group for Women in Shreveport, La., on July 6, 2022. Doctors in states with strict abortion restrictions say an increasing number of pregnant women are seeking early prenatal testing, hoping to detect serious problems while they still have time to choose whether to continue the pregnancy. (AP Photo/Ted Jackson, File)

  • Copy Link copied

WASHINGTON (AP) — In Utah, more of Dr. Cara Heuser’s maternal-fetal medicine patients are requesting early ultrasounds, hoping to detect serious problems in time to choose whether to continue the pregnancy or have an abortion.

In North Carolina, more obstetrics patients of Dr. Clayton Alfonso and his colleagues are relying on early genetic screenings that don’t provide a firm diagnosis.

The reason? New state abortion restrictions mean the clock is ticking.

Since Roe v. Wade was overturned , many health care providers say an increasing number of patients are deciding the fate of their pregnancies based on whatever information they can gather before state bans kick in. But early ultrasounds show far less about the condition of a fetus than later ones. And genetic screenings may be inaccurate.

FILE - Maryland Gov. Larry Hogan addresses supporters at the Maryland statehouse, Jan. 10, 2023, in Annapolis, Md. Republicans hoping to pick up an open U.S. Senate seat in deep blue Maryland have the most competitive candidate they’ve had in decades. But Hogan will need more than GOP support at a time when Democrats' outrage remains high about the Supreme Court’s decision to strike down constitutional protections for abortion. (AP Photo/Julio Cortez, File)

When you find out your fetus has a serious problem, “you’re in crisis mode,” said Sabrina Fletcher, a doula who has helped women in this predicament. “You’re not thinking about legal repercussions and (state) cutoff dates, and yet we’re forced to.”

About half of states ban abortion or restrict it after a certain point in pregnancy. In Utah, it’s generally illegal after the 18-week mark; in North Carolina, after 12 weeks.

This leaves millions of women in roughly 14 states with no option to get follow-up diagnostic tests in time to feasibly have an abortion there if they wanted, a paper published last March in the journal Obstetrics and Gynecology found. Even more states have abortion cutoffs too early for mid-pregnancy ultrasounds.

“More people are trying to find these things out earlier to try to fit within the confines of laws that in my mind don’t have a place in medical practice,” said Alfonso, an OB-GYN at Duke University.

CHECKING FOR PRENATAL PROBLEMS

When done at the right time, doctors said prenatal testing can identify problems and help parents decide whether to continue a pregnancy or prepare for a baby’s complex needs after delivery.

One of the most common tests is the 20-week ultrasound, sometimes called an “anatomy scan.” It checks on the fetal heart, brain, spine, limbs and other parts of the body, looking for signs of congenital problems. It can detect things like brain, spine and heart abnormalities and signs of chromosomal problems such as Down syndrome. Follow-up testing may be needed to make a diagnosis.

The type of ultrasounds patients receive – and when in pregnancy they have one done – can vary depending on the risk level of the patient, as well as the equipment and policies each practice has. For example, some women may have a first-trimester ultrasound to estimate a due date or check for multiple fetuses. But it’s not standard practice because it is too early to see many of the fetus’ limbs and organs in detail, the American College of Obstetricians and Gynecologists says.

It’s impossible to spot problems like serious heart defects much before mid-pregnancy because the fetus is so small, Heuser said. Nonetheless, she said, more patients are having ultrasounds at 10 to 13 weeks to get access to abortion if needed.

Experts say there are no statistics on exactly how many people opt for early ultrasounds or make choices based on them. But some health care providers say they’ve noticed an uptick in requests for the scans, including Missouri genetic counselor Chelsea Wagner. She counsels patients from around the nation through telehealth, frequently discussing the results of ultrasounds and genetic tests.

Wagner said these early ultrasounds can’t provide the assurance patients are looking for because “you can’t give somebody an ‘everything looks good’ or a clean bill of health off of an ultrasound at 10 weeks.”

Doctors also can’t make a firm diagnosis from a genetic screening, which is done at 10 weeks gestation or later.

These screenings, also called “non-invasive prenatal tests,” are designed to detect abnormalities in fetal DNA by looking at small, free-floating fragments circulating in a pregnant woman’s blood.

They screen for chromosomal disorders such as trisomy 13 and 18, which often end in miscarriage or stillbirth, Down syndrome and extra or missing copies of sex chromosomes.

The accuracy of these tests varies by disorder, but none is considered diagnostic.

Natera, one of only a handful of U.S. companies that makes such genetic tests, said in an email that prenatal test results are reported as either “high risk” or “low risk” and that patients should seek confirmatory testing if they get a “high risk” result.

Some may be pretty accurate, doctors said, but false positives are possible. In 2022, the Food and Drug Administration issued a warning about the screenings, reminding patients and doctors that results need further confirmation.

“While genetic non-invasive prenatal screening tests are widely used today, these tests have not been reviewed by the FDA and may be making claims about their performance and use that are not based on sound science,” Jeff Shuren, the director of the FDA’s Center for Devices and Radiological Health, wrote in a statement.

The agency is poised to release a new regulatory framework in April that would require prenatal screenings, and thousands of other lab tests, to undergo FDA review.

AN ‘AWFUL’ DECISION TO MAKE

Even before Roe was overturned, pregnant patients have sometimes been confused by what prenatal testing does – or doesn’t – reveal about the pregnancy or fetus, said bioethicist Megan Allyse, whose research focuses on emerging technologies around women’s reproductive health. She said it’s important for doctors to go over the limitations of such screens and emphasize that the results they receive are not diagnoses.

Alfonso and Wagner said they advise getting diagnostic tests too. In addition to amniocentesis, which removes and tests a small sample of cells from amniotic fluid, these also include CVS, or chorionic villus sampling, which tests a small piece of tissue from the placenta. Both carry a small risk of miscarriage.

But lately, Wagner said, there’s “more urgency to patients’ decisions” in many states.

That’s because of the specifics of test timing. It can take a week or two to get the results of genetic screenings. CVS is offered at 10 to 13 weeks gestation, with initial results taking a few days and more detailed results around two weeks. Amniocentesis is typically done at 15 to 20 weeks, with similar timing for results.

If a state has a 12-week abortion ban, for instance, “some people may have to act on a screening,” Alfonso said.

Wagner said she’s had to counsel patients who couldn’t afford to travel out of state for an abortion if they waited for diagnostic testing.

“They are forced to use the information they have to make choices they never thought they’d have to make,” she said.

Some states restrict abortion so early that women would not have the chance to get any prenatal testing done before the cutoff.

That was the case for 26-year-old Hannah in Tennessee, which has a strict abortion ban. An ultrasound in late November, at about 18 weeks gestation, revealed she had amniotic band sequence, which is when very thin pieces of the amniotic membrane get attached to the fetus, sometimes causing fetal amputation and other problems. In Hannah’s case, the bands were attached to many of her baby boy’s body parts and ripped open multiple areas of his body.

She called clinics in Ohio and Illinois looking for a place to terminate the pregnancy, while her genetic counselor’s office phoned roughly six facilities. She finally found a clinic 4 ½ hours away in Illinois and had the procedure in early December at 19 weeks gestation. A set of results from the amniocentesis – which was done to look for the cause of the problem – came back the day after her abortion, and other results after that.

Hannah, who didn’t want her last name used for fear of backlash, said it’s “awful” to have to think about state timelines, and to travel long distances out of state, when dealing with something like this. But she’s grateful she had a firm diagnosis from the ultrasound and enough information to feel confident in her decision, which she made so her baby wasn’t in “pain and misery.”

“I know some women are not that lucky,” Hannah said. She named her son Waylen.

Ungar reported from Louisville, Kentucky.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

LAURA UNGAR

IMAGES

  1. First-trimester determination of fetal gender by ultrasound: measurement of the ano-genital

    fetal gender assignment by first trimester ultrasound

  2. How Many Months Can You Find Out Gender of Baby

    fetal gender assignment by first trimester ultrasound

  3. Fetal gender assignment by first‐trimester ultrasound

    fetal gender assignment by first trimester ultrasound

  4. 14 weeks pregnant ultrasound gender

    fetal gender assignment by first trimester ultrasound

  5. First Trimester Ultrasound Diagnosis of Fetal Abnormalities by Rabih Chaoui Alfred Z. Abuhamad

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  6. First-Trimester Determination of Fetal Gender

    fetal gender assignment by first trimester ultrasound

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COMMENTS

  1. Fetal gender assignment by first-trimester ultrasound

    Prenatal gender assignment by ultrasound has a high accuracy rate at 12-14 weeks. These results indicate that invasive testing can probably be carried out in fetuses identified as males at this gestational age.

  2. Fetal gender assignment by first-trimester ultrasound

    Prenatal gender assignment by ultrasound has a high accuracy rate at 12-14 weeks. These results indicate that invasive testing can probably be carried out in fetuses identified as males at this gestational age. However, in fetuses identified as female at a CRL of <62.6 mm, despite the relatively …

  3. 341: Fetal gender assignment by first trimester ultrasound: can it be

    Early gender assignment by 1 st trimester ultrasound can be achieved with reasonable accuracy in most women, regardless of fetal sex. A higher BMI is associated with a lower rate of adequate image acquisition, but does not influence correct gender identification if the appropriate image is captured.

  4. Fetal gender assignment by first-trimester ultrasound

    4 to 12 6 weeks and 100% at 13 to 13 6 weeks. Conclusion Prenatal gender assignment by ultrasound has a high accuracy rate at 12-14 weeks. These results indicate that invasive testing can probably be carried out in fetuses identified as males at this gestational age.

  5. First trimester identification of fetal sex by ultrasound

    Fetal sex assessment by transabdominal ultrasound was performed in 567 fetuses at 11-14 weeks' gestation (CRL: 45-84 mm). A mid-sagittal view of the genital region was obtained. The angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was measured.

  6. Accuracy of sonographic fetal gender determination: predictions made by

    Fetal gender was predicted using the sagittal plane only in the first trimester and either the sagittal or transverse plane in later trimesters. Phenotypic gender confirmation was obtained from hospital records or direct telephone contact with women postnatally. Results: Results confirmed 100% accuracy in predictions made after 14 weeks gestation.

  7. First trimester determination of fetal gender by ultrasonographic

    The most definitive method of determining the gender of an embryo is the biopsy of the chorionic villus under ultrasound, but this is an invasive procedure with a 0.5% to 1.0% chance of fetal loss (1, 2). Another method of determining gender is to analyze the cell-free fetal DNA in the mother's blood.

  8. Learning Curve in Determining Fetal Sex by First Trimester Ultrasound

    Methods. A prospective study was conducted on 400 pregnant patients to determine the fetal sex by ultrasound scan between 11-13+6 weeks of gestation. A midsagittal plane of the fetus was obtained by two sonographers who were newly trained for measuring nuchal translucency. It would be assigned as male if the fetal phallus was in the cranial ...

  9. First-trimester determination of fetal gender by ultrasound

    In the late nineties, a new method based on first trimester fetal ultrasonography was developed to determine fetal sex earlier. This involved measuring the angle of the genital tubercle to a horizontal line through the lumbosacral skin surface in a mid-sagittal plane with the fetus in a natural position [3] , [4] .

  10. Fetal gender assignment by first‐trimester ultrasound

    The objective was to assess the feasibility and accuracy of fetal sex identification during the first trimester ultrasound exam and to establish a baseline for future studies on the accuracy of this method in pregnancy. 21 Highly Influenced 6 Excerpts

  11. Fetal gender assignment by first-trimester ultrasound

    Prenatal gender assignment by ultrasound has a high accuracy rate at 12-14 weeks. These results indicate that invasive testing can probably be carried out in fetuses identified as males at...

  12. High sensitivity and specificity in fetal gender identification in the

    This study is the first prospective study to compare and report the accuracy of NIPS and ultrasound scan in determining fetal gender in the first trimester. In a previous study, Efrat et.al. demonstrated an accuracy of 93% in gender assignment in the first-trimester scan in singleton pregnancy by examination of the angle of the genital tubercle .

  13. Fetal gender assignment by first-trimester ultrasound

    Search worldwide, life-sciences literature Search. Advanced Search Coronavirus articles and preprints Search examples: "breast cancer" Smith J

  14. First-trimester determination of fetal gender by ultrasound

    Prenatal sex assignment at the time of first trimester ultrasound screening has a high accuracy rate, and the accuracy improved with increasing gestational age, which suggests that clinically important decisions, such as chorionic villus sampling, are to be made based on fetal sex, should be delayed until the latter part of the second trimester.

  15. Accuracy of fetal gender determination in the first trimester using

    20814877. 10.1002/uog.8812. To evaluate the accuracy of three-dimensional (3D) ultrasound in fetal gender assignment in the first trimester. A series of pregnant women attending at 11 to 13 + 6 weeks for the nuchal translucency (NT) scan were enrolled into the study. An ultrasound volume of each fetus was obtained and stored for offline analysis.

  16. First-trimester determination of fetal gender by ultrasound

    In the late nineties, a new method based on first trimester fetal ultrasonography was developed to determine fetal sex earlier. This involved measuring the angle of the genital tubercle to a horizontal line through the lumbosacral skin surface in a mid-sagittal plane with the fetus in a natural position [3], [4].

  17. Fetal sex assignment by first trimester ultrasound: a Tunisian

    19813214 10.1002/pd.2374 To assess the feasibility and accuracy of fetal sex identification during the first trimester ultrasound exam. A prospective study was carried out on 312 fetuses at 11-14 weeks' gestation. The genital region was examined by transabdominal ultrasound.

  18. The ultrasound identification of fetal gender at the gestational age of

    The positive predictive value for the ultrasound imaging gender identification was 87.6% for the male fetuses and 96.8% for the female fetuses. That is to say, reporting a male gender in the ultrasound imaging performed in the 11 th or 12 th weeks of pregnancy is likely to be 87.6% correct and reporting a female gender is likely to be 96.8% ...

  19. Post-Roe v. Wade, more patients rely on early prenatal testing as

    FILE - An operating room technician performs an ultrasound on a patient at Hope Medical Group for Women in Shreveport, La., on July 6, 2022. Doctors in states with strict abortion restrictions say an increasing number of pregnant women are seeking early prenatal testing, hoping to detect serious problems while they still have time to choose whether to continue the pregnancy.