Estudo morfológico do útero de fetos humanos: diferenças na organogênese relacionadas à anencefalia

Abstract

Neural tube defects (NTD) are one of the most common congenital malformations affecting the central nervous system; anencephaly is the most severe manifestation of NTD. The hypothesis of this study is that anencephaly affects the formation of the human uterus during fetal life. Hence, the objective of this research is to compare the uterine biometric parameters of female fetuses with and without anencephaly. As a method, between 12 and 22 weeks after conception (WPC), 34 female fetuses (22 normal and 12 anencephalic) were investigated. Biometric characteristics were obtained. The dissection is performed with the fetus in the supine position; abdominal and pelvic tissues are accessed by bilateral subcostal incisions. At this moment, a first photographic record is made, and the pelvis, containing the entire genitourinary system, is extracted en bloc. The fetuses were then subjected to pelvic dissection and individualization of the urinary tract (bladder and urethra) and genital (uterus, vagina, and ovaries) components using a Zeiss Discovery V8 microscope, which permits the acquisition of a second set of images. Measurements of the length and width of the uterus were performed using the Image J software, v. 1.46r. For statistical analysis the SPSS software, v. 13.0, was employed. The significance level was adjusted using the Bonferroni correction (p < 0.0071). Mean comparison tests were carried out and linear correlations were also evaluated for the two groups regarding uterine measurements and anthropometric parameters: age in SPC, weight in grams (g) and crown-rump length (CRL) in centimeters (cm). We observed significant differences in uterine length (mm)/weight (g) × 100 (p = 0.0046) and uterine width (mm)/weight (g) × 100 (p = 0.0013) when comparing the control with the anencephalic group. According to linear regression analysis, correlations between normal fetuses (12.9 to 22.6 WPC) and anencephalic fetuses (40% significance) were shown to be 80% significant and 40% significant, respectively (12.3 to 18.6 WPC). Multiple regression analysis indicates that 40.4% of the variations in uterine length (mm)/weight (g) × 100 and 32.9% of uterine width (mm)/weight (g) × 100 are random variations or due to factors other than age, CVC and anencephaly. In conclusion, we observed that the uterine measurements were greater in the anencephalic group, but the multiple regression analysis suggests that anencephaly it self is not able to explain the variations in uterine measurements. More translational studies are needed to broaden our understanding of how anencephaly may affect uterine formation during the human fetal period.