Sonographic measure techniques of fetal penile length

Prenatal phthalate exposure and fetal penile length and width

BACKGROUND

Phthalates are endocrine-disrupting chemicals with anti-androgenic qualities and studies reported associations between prenatal phthalate exposure and infant genitalia. This study investigated whether increased prenatal phthalate exposure is associated with decreased fetal penile measures.

METHODS

Data was from the New York University Children's Health and Environment Study (2016-2019). Maternal urinary concentrations of 16 phthalate metabolites were quantified at <18 weeks gestation as a proxy for fetal exposure (n = 334 male pregnancies). We retrospectively measured penile length and width using ultrasounds conducted 18-24 weeks gestation (n = 173 fetuses). Associations of maternal urinary levels of phthalates with fetal penile length and width were determined using linear regression models.

RESULTS

57.2% of women were Hispanic, 31.8% Non-Hispanic White, 6.4% Asian, 2.3% Non-Hispanic Black, and 2.3% multiple races. Mean maternal age was 32 years (standard deviation [SD] = 5.7). Mean penile length was 7.13 mm (SD = 1.47) and width was 6.16 mm (SD = 0.87). An inverse relationship was observed between maternal levels of mono-ethyl phthalate and fetal penile length, and mono-(7-carboxy-n-heptyl) phthalate and penile width, though estimates were small and not significant when considering correction for multiple comparisons.

CONCLUSIONS

In our cohort we found no clinically meaningful associations between early pregnancy phthalate exposure and fetal penile length or width.

IMPACT

First-trimester phthalate metabolites were assessed in pregnant women in New York City. Penile length and width were retrospectively measured on clinically assessed ultrasounds conducted ≥18 weeks and <24 weeks of gestation. In this cohort, no clinically meaningful associations were observed between first-trimester prenatal phthalate exposure and fetal penile length. This study contributes to the limited but growing research on the impact of prenatal phthalate exposure on male fetal genital development. The results emphasize that there may not be a clear association between prenatal phthalate exposure and fetal penile length and width, and further research on this topic may be required.

Imaging in fetal genital anomalies

Genital anomalies are a heterogeneous group of congenital pathologies that have become increasingly relevant since the Chicago Consensus of 2005. Their postnatal diagnosis has developed significantly in the last two decades, while prenatal diagnosis seems to be underdeveloped, with few protocols available, fragmented scientific literature, and low diagnostic rates. This review aims to examine the current status of this subspecialty from the perspective of prenatal imaging. Indications for the evaluation of fetal genitalia can be divided into medical and non-medical reasons. Medical reasons include sex-linked disorders, detection of other anomalies, relevant family history, or multiple pregnancy. Non-medical reasons include parental request for sex disclosure. Disclosure of fetal sex may be associated with ethical, legal, and medical issues. The main imaging technology used is 2D ultrasound, although there are other complementary techniques such as 3D, MRI, or Color Doppler. Regarding working methodology, several authors have drawn attention to the lack of standardized protocols and guidelines. Most guidelines tend to limit their recommendations to study indications and ethical issues. Technical proposals, measurements, or working methods have not yet been standardized. Fetal sex determination is usually divided into early and late gestation. Early gestation is based on the sagittal sign. Late gestation is based on direct visualization. There are several measurements to describe male and female genitalia, such as penile length, bilabial diameter, or scrotal diameter. Prenatal diagnosis of genital pathologies presents some particularities such as the wide spectrum of phenotypes, the high frequency of associated deformities, or the time of diagnosis. Some of the most frequent pathologies are ambiguous genitalia, fetal sex discordance, hypospadias, micropenis, clitoromegaly, ovarian cysts, hydro(metro)colpos, and cloacal anomalies. Higher-quality studies and direction from scientific societies through the implementation of clinical guidelines are needed.

Stretched penile length at birth: a systematic review

BACKGROUND

Micropenis is an endocrinological condition that is habitually observed at birth. Diagnosis is made by measuring the stretched penile length, a method established 80 years ago. Discrepancies in the normative data from recent studies raise the need for a current revision of the methodology.

OBJECTIVES

The aims of this systematic review were to compare the different normative data of SPL at birth, to examine the methodological aspects of the technique and to evaluate the independent variables that may be involved.

METHODS

Searches were performed using MEDLINE, EMBASE, Scielo, the Cochrane Library and Web of Science. A combination of the relevant medical terms, keywords and word variants for "stretched penile length", "penile length", "penile size", "newborn" and "birth" were used. Eligibility criteria included normative studies that used the stretched penile length (SPL) measurement on a population of healthy, full-term newborns during the first month of life. The outcomes studied included characteristics of the studies, methodological aspects and independent variables.

RESULTS

We identified 49 studies comprising 21,399 children. Significant discrepancies are observed between the different studies. Methodological aspects seem to be consistent and similar. The main independent variables appear to be ethnic group and gestational age. Main limitations were the absence of studies of entire world regions such as Europe or South America, and the heterogeneity of the ethnic background that complicates the analysis.

CONCLUSIONS

It seems advisable to suggest the creation of customized reference charts for each specific population instead of resorting to the classic cut-off points.

Open-legs axial plane: A standardized methodology and reference values for fetal genital biometry in mid-trimester ultrasound

BACKGROUND

Evaluation of the external genitalia is an important part of prenatal ultrasound. However, there is no standardized methodology that includes biometric measurements and normative data to be able to carry out this evaluation.

OBJECTIVE

To develop a standardized methodology for fetal genital biometry and obtain reference values for use in mid-trimester ultrasound.

STUDY DESIGN

A prospective cross-sectional study was used. 273 male and 253 female fetuses of normal, singleton pregnancies at 18 to 22 weeks were included. Measurements of fetal penis length, penile width and transverse scrotal diameter in male fetuses and bilabial diameter in female fetuses were performed by transabdominal ultrasound. Reference values were calculated for each gestational week.

RESULTS

Realization of the open-legs axial plane is described as a working methodology. Normative data for penile length, penile width, transverse scrotal diameter and bilabial diameter are defined, including mean, minimum and maximum values, range, and 5th, 10th, 90th and 95th percentiles.

CONCLUSIONS

We have provided a standardized methodology using the open-legs axial plane, which would integrate the main measurements. In addition with the normative data constructed from their use, we hope to be able to improve the external genitalia assessment and diagnosis of genital anomalies in mid-trimester ultrasound.