Nursing When Can U Tell the Gender of a Baby

Australas J Ultrasound Med. 2014 Aug; 17(3): 125–130.

Accuracy of sonographic fetal gender determination: predictions fabricated by sonographers during routine obstetric ultrasound scans

Manette Kearin, Dip App Sc (Nursing), BNursing, Grad Dip Ed (principal), DMU, MSc (midwifery), ^one Karen Pollard, ADipDMR, GCertUnivTeach&Acquire, MHEd, MEd, ^two and Ian Garbett, BSc, GDipMathematics, MSc ⁱⁱ

Manette Kearin

^aneS Declension Ultrasound for Women, Wollongong, New South Wales, Australia

Karen Pollard

ⁱⁱCharles Sturt University, Wollongong, New South Wales, Australia

Ian Garbett

ⁱⁱCharles Sturt University, Wollongong, New Southward Wales, Australia

Abstract

Objectives: The purpose of this study was to make up one's mind the accuracy of sonographer predictions of fetal gender during routine ultrasounds. Primarily, the study sought to investigate the accuracy of predictions made in the first trimester, as requests from parents wanting to know the gender of their fetus at this early scan are condign increasingly common. 2nd and tertiary trimester fetuses were included in the study to confirm the accurateness of later predictions. In addition, the mother's decision to know the gender was recorded to determine the prevalence of women wanting prenatal predictions. Methods: A prospective, cross sectional study was conducted in a specialist private obstetric practice in the Illawarra, NSW. A total of 640 fetuses beyond three trimesters were examined collectively by seven sonographers. Fetal gender was predicted using the sagittal plane only in the kickoff trimester and either the sagittal or transverse airplane in later on trimesters. Phenotypic gender confirmation was obtained from infirmary records or directly telephone contact with women postnatally.

Results: Results confirmed 100% accuracy in predictions made after 14 weeks gestation. The overall success charge per unit in the offset trimester group (11–14 weeks) was 75%. When excluding those scans where a prediction could not exist made, success rates increased to 91%. Results were less accurate for fetuses younger than 12 weeks, with an overall success rate of 54%. Male fetuses under 13 weeks were more likely to accept gender incorrectly or unable to be assigned. After 13 weeks, success rates for correctly predicting males exceeded that of female fetuses. Statistical differences were noted in the success rates of individual sonographers. Sixty 7 pct of women were in favour of knowing fetal gender from ultrasound. Publicly insured women were more likely to request gender disclosure than privately insured women.

Conclusions: Sonographic gender conclusion provides high success rates in the kickoff trimester. Results vary depending on sonographer feel, fetal age and fetal gender. Practice guidelines regarding gender disclosure should exist adult. Predictions prior to 12 weeks should exist discouraged.

Keywords: fetal gender, get-go trimester, gender determination, obstetric ultrasound, routine ultrasound, sonographer

Introduction

It is about 40 years since ultrasound was kickoff used to evaluate the obstetric patient, ¹ today ultrasound scanning is firmly entrenched in antenatal intendance. The value of ultrasound screening in detecting and monitoring fetal malformation, placental position and multiple pregnancies is undeniable ² . Initially fetal gender assignment by ultrasound was indicated in fetuses at risk of sex and X‐linked disorders in order to reduce the need for invasive testing. ^two However, it is now typically performed in response to parental wishes.

Most commonly gender predictions are made in the second or third trimester, however with improvements in ultrasound applied science ⁴ identification of fetal gender in the offset trimester is becoming a reality.

The 1989 study conducted by Emerson et al. ⁱⁱⁱ was the first to identify the 'sagittal sign' ³ as a means of determining gender at first trimester ultrasounds. This written report found that a focal burl creating a cranial astute angle indicated male ballocks, while a bulge creating a caudal acute angle indicated female genitalia ⁱⁱⁱ (Figure 1).

Diagrammatic representation of the 'sagittal sign' described by Emerson.

A like description was utilised by Whitlow, et al. ⁴ When viewing a fetus in the sagittal plane, a cranial or vertically directed fetal phallus was noted to be a feature of the male fetus. Female genitalia demonstrate a caudally directed phallus which is considered to represent the clitoris. ⁴

Some studies ^{5 , 6} take explored the possibility of quantifying the angle of the tubercle or phallus. The bending of the genital tubercle to a horizontal line through the lumbosacral surface was measured with a protractor. An angle of > 30 ° was assigned a male fetus. A female person was assigned when the genital tubercle was parallel or convergent to the horizontal line (< 10°). In the report conducted by Youssef, et al. ⁶ the best cutting‐off for male person gender determination was found to be between 27° and 29°. These studies involved an independent researcher performing measurements away from the clinical setting. It was an intention of this study to brand subjective predictions during routine scans without the patient being aware that gender was existence assessed (when required). For these reasons quantifying the angle was non considered.

The numbers of parents desiring to know their fetus'south gender was also of involvement. A study conducted by Shipp, et al. ^vii plant that 58% of parents had learned or planned to acquire the gender of their baby. Their study was conducted in 2001 at a large referral centre in Boston (USA). In a written report conducted at the Nepean Infirmary (NSW, Australia) in 2008, it was found that 64% of mothers wanted to know the sex activity of their baby. ⁸ The written report conducted at Nepean Hospital, found common factors related to maternal desire to seek fetal gender. These included low pedagogy level, depression income level, increased parity and having no partner. ⁸ The common demographic factors plant in the study past Shipp, et al. ^seven included partners non employed in fulltime work, low household income, unwed mothers, maternal age (< 22 and > forty years) and the lack of a higher caste. While the scope of this written report did not extend to investigating the factors impacting the decision to pursue fetal gender determination, it did seek to quantify the numbers of patients making gender requests. The report allowed definition of those patients with individual health encompass to those birthing through the public system.

At the exercise where the present study was conducted, requests for fetal gender predictions during first trimester, routine nuchal translucency (NT) screening were being frequently heard. For sonographers information technology was becoming increasingly difficult to navigate the event of gender disclosure. Sonographers at this practice were bully to explore their own abilities and limitations. At that place was besides a need to develop formal practice policy guidelines regarding disclosure of fetal gender.

Every bit a result, this report sought to investigate the feasibility and accuracy of gender predictions fabricated by sonographers during routine scans. The results would so be used to guide sonographers and develop practice guidelines.

Methods and materials

This prospective study was conducted at a individual specialist obstetrics/gynaecology practice in the Illawarra (NSW, Commonwealth of australia). The practice is the chief referral middle in the Illawarra and S Coast region. Women were referred past general practitioners, hospital doctors, midwives and private obstetricians. Of the women who attended the practice for their obstetric ultrasound scans, approximately one third had individual health insurance. Two thirds of the women used the publicly funded, universal health care system operated past Medicare Australia and were likely to nascency at the local public hospital.

In the Illawarra, women more often than not had three routine scans during their pregnancy. These include the first trimester scan (NT scan), a 19–week morphology scan, and a third trimester fetal wellbeing scan (34 weeks).

All scans were attended on Full general Electric E8 ultrasound machines by 1 of seven sonographers. Sonographer feel ranged from a third yr trainee sonographer to a sonographer with more thirty years feel. During the study period, two locum sonographers were employed to cover permanent staff on leave. While both were very experienced, neither performed any scan in the first trimester group.

Standard policy and procedure guidelines were strictly followed throughout the study period (specific practice and ASUM guidelines ⁹ ). The length of scan fourth dimension was non increased for the purpose of obtaining study data.

Ethics approval was obtained from Charles Sturt University (approval number 414/2012/15).

Pregnant women who attended the do for a routine scan within the study period (Jan 2013) were recruited. Patients booked for nuchal translucency scans (first trimester), morphology scans (2d trimester) and fetal growth and wellbeing scans (third trimester) were included. Patients nether the age of 16 and those unable to read or understand English were excluded from the study.

On arrival for their ultrasound, women were informed of the study and were provided with written information. Informed consent was and then obtained from those women willing to participate. Participation was voluntary. Women were reassured that the gender prediction would not exist conveyed to them unless they specifically requested it. The signed consent grade and a data drove canvass were attached to the referral form. Prior to commencing the scan, sonographers ensured the consent form was complete and provided an opportunity for further information or clarification. The ultrasound was then conducted in the usual manner.

At the conclusion of each scan, when the adult female had left the room, sonographers completed the data collection form. The form independent simple options enabling the sonographer to complete information technology quickly and easily past placing a cross in the appropriate boxes. The form indicated the attending sonographer, pertinent patient details, age of fetus, gender prediction, reason for a failure to predict gender (if applicative) and the woman's want to know gender. In one case complete, the data drove class was sealed in an envelope and securely stored with the expected commitment engagement and place of commitment recorded on the front.

Subsequently the delivery date had passed, the phenotypic gender was sought and recorded on the information sheet. The nascency gender was obtained through infirmary records or by direct phone contact with women.

Fetuses in the 2nd and third trimesters were scanned in either transverse or sagittal planes at the discretion of the attention sonographer. Prior to the study, sonographers were instructed to view the genital area of first trimester fetuses in a sagittal view merely. A caudally directed tubercle was to be recorded a female, a cranial directed tubercle was recorded as a male, using the same technique described by Emerson, et al. ³ The post-obit ultrasound images draw examples of both a male and female fetus (Effigy 2 and ​ 3).

Male fetus at 12 weeks 5 days.

Female person fetus at 12 weeks 3 days.

During the study period, scans were performed on a total of 640 fetuses. Third trimester gender predictions were made on 217 fetuses, including one twin pregnancy. Two hundred and fifteen fetuses were included in the second trimester group including five twin pregnancies. The first trimester group included 208 fetuses of which there were three twin pregnancies. Gestational age was calculated from either LMP, a previous dating scan or taken from referral details.

All information was entered and tabulated using the Microsoft Excel program. The iii trimester groups were entered separately to allow for private analysis. Statistical analysis using Chi squared test and the Z statistic were used, with P < 0.05 considered statistically pregnant.

Results

Of the 640 fetuses, 323 (50.v%) were born male and 317 (49.5%) were born female. Only 1 fetus was excluded from the written report due to cryptic genitalia and other anomalies (Trisomy 21 was confirmed on invasive testing). Phenotypic gender was confirmed for all study participants.

Gender assignment was possible in 215 of the 217 (99%) fetuses in the 3rd trimester grouping. Increased maternal torso mass index (BMI) and unfavourable fetal prevarication contributed to the two fetuses without gender assignment. Correct gender assignment was accomplished in all remaining fetuses.

Gender assignment was possible in 214 of 215 (99.5%) fetuses in the second trimester browse. In one example the gender could not exist determined due to increased maternal BMI, uterine fibroids and unfavourable fetal lie. Right gender was achieved in all remaining fetuses.

Results were significantly dissimilar for the start trimester group. Gender assignment was attempted in 87% (181 of 208) of fetuses. In the majority of cases the reasons for inability to predict gender included unfavourable lie and increased maternal BMI.

The overall success rate of predicting fetal gender in the start trimester was 75% (156/208). When excluding those fetuses where a prediction was non made, correct conclusion increased to 91% (156/181). The full results of the starting time trimester group are shown in Table 1.

Table one

First trimester results.

Gestational age	xi–11+6 weeks		12–12+6 weeks		xiii–thirteen+half dozen weeks		14–14+6 weeks		15–15+6 weeks
Gender not assigned	three/24	12.5%	19/143	thirteen%	5/38	13%	0		0
Correct male	three/8	37.v%	54/78	69%	sixteen/nineteen	84%	1/1	100%	1	100%
Incorrect male	iii/8	37.5%	xi/78	xiv%	1/nineteen	5%	0		0
Right female	10/sixteen	62.5%	55/64	86%	15/21	71%	1/i	100%	0
Incorrect female person	5/16	31%	3/64	5%	2/21	x%	0		0
Total correct when attempted	13/21	62%	110/124	89%	30/33	91%	2/2	100%	1	100%
Total incorrect when attempted	8/21	38%	14/124	xi%	iii/33	nine%	0		0
Overall correct	13/24	54%	110/143	77%	thirty/38	79%	two/2	100%	one/1	100%
Total cases studied	24		143		38		2		ane

The above table demonstrates how accuracy rates improved with advancing gestational historic period. For fetuses in the 11–11week six‐24-hour interval group, success rates were poor. Only 54% (xiii/24) were correctly predicted. Fetuses between 12–12 weeks 6 days, demonstrated a loftier degree of accuracy in predictions. Overall, 77% (110/143) of fetuses in this group were predicted correctly. For fetuses betwixt 13–13 weeks 6 days, success rates rose to 79% (30/38). Although only a small number of fetuses were examined betwixt 14 weeks and sixteen weeks, all were correctly predicted.

The feasibility rate of making predictions was relatively stable through each of the groups. For those fetuses in the 11–week group the 'unable to be assigned' rate was 12.v%. While 13 % of fetuses in the 12–calendar week and 13 week groups were unable to exist assigned.

Gender‐specific differences in accuracy rates were noted. Predictive errors were more mutual in young male fetuses. Male fetuses under 12 weeks gestation were correctly predicted 37.5% of the fourth dimension compared to 62.5% of female fetuses in the same grouping. For male fetuses under xiii weeks, 69% were correctly predicted compared to 86% of females. Once fetuses reached 13 weeks, more than male fetuses were correctly predicted compared to female fetuses (84% to 71%). Using a Chi‐squared Test, results co-ordinate to gender were found to be statistically significant (87.ii% confidence).

Gender‐specific differences in feasibility rates were also noted. In the 11 and 12 calendar week groups combined, 17% of males were 'unable to exist assigned' compared to nine% of females. By 13 weeks more females were represented in the 'unable to exist assigned' category. Gender specific differences are highlighted in Table two.

Table 2

Gender specific differences in the starting time trimester.

There was a statistical departure in the accurateness rates among sonographers (P value = 0.00055). When comparing the 5 sonographers who scanned fetuses in the start trimester, the overall success rates were 77%, 49%, 86.5%, 71% and 100%. The rate of inability to predict was seven%, 41%, 5%, 11% and 0%. The rate of wrong predictions was 16%, 10%, 8%, and eighteen% and 0% (Table iii). It is important to note that the sonographer who obtained a 100% accuracy charge per unit had only attended six beginning trimester ultrasound scans within the written report period. The remaining four sonographers attended 28 ultrasound scans or more.

Table 3

Individual sonographer results.

Of the total study sample, 67% of women wanted to know or had already sought fetal gender determination. Of the privately insured women, only 50% opted to know their fetus' gender compared to 75% of women inside the public health organization.

Discussion

The results of this study bespeak ultrasound gender predictions by sonographers are 100% sensitive for accurately predicting the gender in the second and third trimesters. The overall success rate of correctly identifying fetal gender in the start trimester was much lower (75%). This issue was also lower than several other studies. ^{5 , half-dozen , ten , 11} There are several possible explanations for this finding. Firstly, this study included predictions fabricated by sonographers with varying levels of experience. In detail, the trainee sonographer (sonographer B) recorded significantly more fetuses in the 'unassigned' group, thus affecting overall success rates. Secondly, the practise where this report was attended has a policy allowing support people and their children to attend ultrasounds. Consequently, sonographers often deal with multiple distractions. In studies where predictions were made by researchers away from the clinical setting, ^{5 , vi , x , 11} these factors would be negated. The study conducted past Whitlow, et al. ⁴ was attended nether similar conditions to this study. Predictions were made by visual assessment of the management of the fetal phallus only by multiple sonographers in real‐time scanning situations. ⁴ Their success rates were 75% for 12 weeks and 79% at thirteen weeks ⁴ which are comparable to the results in this report.

It must as well be noted that the study did not permit for an increase in browse time and many parents did not wish to know the gender of their fetus. Some prediction errors may have been made as a outcome of time constraints or by sonographers attempting to minimising parents viewing the fetal genital area.

This study demonstrated a stiff correlation between fetal historic period and accuracy rates of gender predictions. Interestingly success rates for predictions on fetuses nether 12 weeks were very poor (54%). When using the z‐test statistic it was institute that the predictive ability of sonography (using this sample) was not significantly better than guessing. For fetuses between 12 weeks and 12 weeks and 6 days overall success rates reached 77%. This climbed to 79% and and then 100% in the following weeks. Comparable results were noted in other studies. ^{4 , 10} The study by Whitlow, et al. ⁴ plant that the overall success rates of correctly assigning fetal gender increased with gestational historic period from 46% to 75%, 79% and 90% at eleven, 12, 13 and 14 weeks respectively. The written report past Hsiao, et al. ¹⁰ showed the same tendency. Success rates rose from 71.ix% at 11 weeks to 92% and 98.3% in subsequent weeks. ¹⁰

Feasibility rates in this written report were not found to exist afflicted by gestational age. Approximately 12–thirteen% of fetuses were classified as 'unable to exist assigned' in the eleven week, 12 calendar week and 13 week groups. These results were not reflected in other studies. ^{ii , 4} Whitlow, et al. ^four found that at 11 weeks, 41% of fetuses were unable to be assigned. This decreased to 13%, viii% and 2% at 12, xiii and 14 weeks respectively. ^four The written report conducted by Hsiao, et al. ¹⁰ found fetal gender was unable to be assigned in 40.6% of fetuses in the xi week grouping. ¹⁰ This brutal to v.4% in the 12–week group and 2.3% in the xiii week grouping. ¹⁰

Results of this study bespeak that more than errors occur with immature male fetuses than immature female fetuses. The accurateness of predicting males compared to females has shown conflicting results in previous studies. Several studies ^{12 – fifteen} found significant differences between success rates of predicting male fetuses. Younger males were predicted incorrectly more usually. In contrast, the study conducted by Chelli, et al. ¹¹ found accuracy rates were non different betwixt sexes (87.9% to 83.iii%).

Differences in success rates between genders are not unexpected when because normal embryology. From 12 weeks gestation pronounced gender specific changes occur in the construction of the urogenital sinus. ¹⁵ In males the urogenital sinus is replaced by the scrotal and urethral raphe. This process, combined with elongation of the genital tubercle, displaces the phallus to a raised position. ¹⁵ Therefore male fetuses show an increase in the angle of the genital tubercle from the horizontal with increasing crown‐rump length. ¹⁵ Until this procedure has occurred gender predictions are unreliable.

The experience and skill of the sonographer requires consideration. This written report highlighted the differences between success rates of an inexperienced sonographer and those with at least five years experience. Results showed while the trainee sonographer had comparable numbers of incorrect predictions, she was much more probable to refrain from making a prediction. The like study by Whitlow, et al. ⁴ found no statistical difference in the accuracy rates among six different operators.

Information technology is also important to notation that sonographers in this report were completing high volumes of early fetal scans, and every bit a effect, may be more confident in making predictions than those seeing few obstetric patients. Further study opportunities be to examine the impact of experience levels and sonographer accurateness rates. In particular, a report comparing sonographers working in full general practices to those working in a specialist practice would be of interest.

In this study the proportion of parents who asking fetal gender decision varied between the women in the public health organisation and women with private health insurance. While individual demographic factors were not recorded, it may be possible that fewer privately insured women choose prenatal gender determination due to reasons associated with their typically college maternal age, education and economic status. This assumption is supported past Shipp, et al. ⁷ and Bauman, et al. ⁸ whose studies identified common demographic factors that lead to an increased want to know fetal gender.

Decision

Requests from parents for fetal gender decision at ultrasounds are common. These requests are at present being heard during starting time trimester scans. While sonographers who perform high volumes of obstetric ultrasounds are very authentic in providing gender predictions in the 2d and third trimesters of pregnancy, lower accuracy rates are obtained in the starting time trimester. Sonographers need to make women enlightened that errors occur with early predictions, peculiarly those made prior to 12 weeks, and that predictions cannot always be made. Sonographers should have an awareness of their skill and limitations in order to fairly counsel women. Specific practice policies regarding gender disclosure would provide guidance and protection to staff.

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Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5024945/

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