Study of the ureter structure in anencephalic fetuses

Neural tube defects and uterus development in human fetuses

One of the most common malformations of the central nervous system is related to embryonic neural tube alterations. We hypothesized that anencephaly affects the development of the uterus during the human second trimester of pregnancy. The objective of this study was to study the biometric parameters of the uterus in fetuses with anencephaly and compare them with normocephalic fetuses at that important. In our study, 34 female fetuses were analyzed, 22 normal and 12 anencephalic, aged between 12 and 22 weeks post-conception (WPC). After dissection of the pelvis and individualization of the genital tract, we evaluated the length and width of the uterus using the Image J software. We compared the means statistically using the Wilcoxon-Mann-Whitney test and performed linear regression. We identify significant differences between the uterus length (mm)/weight (g) × 100 (p = 0.0046) and uterus width (mm)/weight (g) × 100 (p = 0.0013) when we compared the control with the anencephalic group. The linear regression analysis indicated that 80% significance was found in the correlations in normocephalic fetuses (12.9 to 22.6 WPC) and 40% significance in anencephalic fetuses (12.3 to 18.6 WPC). The measurements of the uterus were greater in anencephalic group but there are no difference in the uterine width and length growth curves during the period studied. Further studies are required to support the hypothesis suggesting that anencephaly may affect uterine development during the human fetal period.

Morphology of the fetal renal pelvis during the second trimester: Comparing genders

OBJECTIVES

Many studies of neonates have shown that renal pelvis ectasia is more common in boys. The aim of this study was to determine whether there are structural differences in the renal pelvis between male and female fetuses in the second trimester of gestation.

MATERIAL AND METHODS

We studied 34 renal pelvises obtained from 34 human fetuses (17 males and 17 females), ranging in age from 13 to 23 weeks postconception. The renal pelvis tissue was stained with Masson's trichrome to quantify connective and smooth muscle cells (SMC). The tissue also was fixed for scanning electron microscopy (SEM) in a modified Karnovsky solution. The images were captured with an Olympus BX51 microscope and Olympus DP70 camera. The stereological analysis was done with the Image-Pro and ImageJ programs, using a grid to determine volumetric densities (Vv). Means were statistically compared using simple linear correlation and the Mann-Whitney test (p<0.05).

RESULTS

Quantitative analysis indicated differences (p=0.0275) in Vv of connective tissue in male renal pelvises (mean=55.3%) compared to female ones (mean=51.46%). Quantitative analysis indicated a significant difference (p=0.0002) in SMC in male renal pelvises (mean=12.57%) compared to female ones (mean=16.22%). When we compared the SMC at different ages, we did not find any correlation in male (r²=0.2657, p=0.3027) or female fetuses (r²=0.3798, p=0.1326). When we compared the connective tissue at different ages, we did not find any correlation in female fetuses (r²=0.3798, p=0.2870), but we did observe a positive correlation between the connective tissue and age in male fetuses (r²=0.8308, p<0.0001). SEM showed that the collagen fibers had no differences between male and female.

CONCLUSION

The renal pelvis presents significant structural differences between male and female fetuses. The renal pelvis in males had less SMC and presented a positive correlation of connective tissue with age and the renal pelvis in female had less connective tissue without correlation with the age.

LEVEL OF EVIDENCE

III.

Study of prostate growth in prune belly syndrome and anencephalic fetuses

BACKGROUND

To compare the growth of the prostate in anencephalic, prune belly syndrome (PBS) and control fetuses.

METHODS

We studied 35 prostates from normal human fetuses aged 11-22 weeks postconception (WPC); 15 from anencephalic fetuses aged 13-19 WPC; and 6 from PBS fetuses aged 13-31WPC. After prostate dissection, we evaluated the prostate length, width and thickness with the aid of a computer program (Image Pro and Image J). The fetal prostate volume (PV) was calculated using the ellipsoid formula: PV = [length × thickness × width] × 0.523. The prostates were dissected and the PV was measured with the aid of the same computer program. Means were statistically compared using the unpaired t-test and linear regression was performed.

RESULTS

In 2 PBS fetuses we observed prostatic atresia. We did not observe significant differences in PV when comparing the control group (PV: 6.1 to 313.81 mm, mean = 70.85 mm: SD = 71.43 mm) with anencephalic fetuses: p = 0.3575 (PV: 5.1 to 159.11 mm, mean = 42.94 mm; SD = 40.11 mm) and PBS fetuses: p > 0.999 (PV: 10.89 to 148.71 mm, mean = 55.4 mm; SD = 63.64 mm). The linear regression analysis indicated that the PV in the control group (r² = 0.3096; p = 0.0004), anencephalic group (r² = 0.3778; p = 0.0148) and PBS group (r² = 0.9821; p < 0.009) increased significantly and positively with fetal age (p < 0.0001).

CONCLUSIONS

We did not observe significant differences in development of the prostate in fetuses with anencephaly and in 2/3 of fetuses with PBS during the fetal period studied. In 1/3 of the PBS fetuses, the prostate had important atresia.

LEVEL OF EVIDENCE

Level III.