Hypothetical role of prostaglandins in the onset of preterm labor after fetal surgery.

Preterm labor is one of the most important factors limiting the advancement of fetal surgery programs. While prostaglandins (PGs) have long been indicated as the key factor in the initiation of labor in humans, there is significant evidence showing that the chorionic membrane acts as a powerful barrier between the decidua/myometrium and amniotic PGs during normal pregnancy. After either open or endoscopic fetal surgery the imperfect, non-hermetical closure of the chorion permits leakage of PGs from the amnionic sac, allowing them to reach the decidua and myometrium. The surgical wound in the chorionic barrier could be the major factor involved in preterm labor and delivery after human fetal surgery.

Ultrastructural study on human placenta from intrauterine growth retardation cases.

A morphological study was performed on 27 human placentas from normal gestations (Group 1) and compared with those from eight cases of intrauterine growth restriction (IUGR) (Group 2). Semithin section light microscopy, transmission, and scanning electron microscopy were carried out on trophoblastic terminal villi, carefully identified under the stereomicroscope. In growth retardation cases, villi appear longer, thinner, and less vascularized, compared to the normal condition. Fibrinoid, an extracellular material of hematic origin, frequently fills villar stroma. The density of apical microvilli appears considerably reduced and occasional microvilli-free areas are observed in growth retardation cases. Moreover, the underlying basal membrane appears significantly thicker than that of normal syncytiotrophoblast. Recently, particular attention has been paid to apoptosis as a possible cell deletion mechanism in growth restriction. In our study, a majority of typical apoptotic features appear indifferently in both IUGR and normal pregnancy. Our data hints that growth retardation might be correlated with a complex of structural changes, suggestive of maternofetal traffic downregulation, but further studies are required to understand the underlying functional mechanisms.

Doppler velocimetry and cytofluorimetric analysis in uterine myomas.

BACKGROUND: To correlate resistance indices (RI) of vessels detected by transvaginal Doppler velocimetry to the proliferative fraction (PF) calculated by flow cytometry in uterine myomas. A prospective study was carried out on patients scheduled for surgery because of symptomatic uterine myomas. A group of 26 myomas characterized by the presence of detectable vessels at Doppler analysis in the inner part of the mass were included in the study. METHODS: The day before surgery patients were studied with both conventional and color Doppler ultrasonography. The volume of the myoma was recorded. The lowest value of RI obtained by Doppler analysis of the vessels within the myoma was considered for the study. Samples from myomas were processed and analyzed by flow cytometry. A PF, representing the cumulative frequency of cells in the S and G2/M phases of the cell cycle, was considered for the analysis. RESULTS: No statistically significant correlation was observed between RI and PF (r = 0.06, p = 0.74). Regression analysis of the intratumoral RI values on the volume of the myoma showed a significant negative correlation (r = -0.46, p = 0.012). CONCLUSIONS: Preoperative Doppler evaluation of uterine myomas did not provide predictive information of the proliferative status of the neoplasm. A significant correlation was found between the volume of the myoma and RI.