Uterine volume

In one of the largest international multicenter studies of raloxifene it was found that, compared with combined hormone replacement therapy (with 17-beta-oestradiol 2 mg + norethisterone acetate 1 mg) 12 months of raloxifene treatment at 60 mg/day was not associated with increased endometrial thickness or uterine volume (31). 

In a prospective study in 77 consecutive women with postmenopausal breast cancer scheduled to start endocrine treatment for breast cancer, using either tamoxifen or an aromatase inhibitor tamoxifen treatment significantly increased endometrial thickness and uterine volume after 3 months (24). In additional, tamoxifen induced endometrial cysts and polyps and increased the size of pre-existing fibroids. In contrast, aromatase inhibitors did not stimulate endometrial growth and were not associated with endometrial pathology. Furthermore, they reduced endometrial thickness and uterine volume in patients who had previously taken tamoxifen. 

In one of these studies, treatment was extended for up to 1 year in 40 premenopausal women with large symptomatic myoma who received mifepristone in doses of5orl0mg daily [70,71].Mean uterine volumes decreased by 48% in both groups by 6 months and to 53% at 1 year. None of the above trials conducted with mifepristone was placebo-controlled. 

It is important to evaluate the uterine and fibroid volumes as patients that show poor reductions in uterine volume post embolization may be more likely to require hysterectomy [4]. MR not only provides easily understood images that can be shown to patients, but also information that can be used to predict future fibroid shrinkage or to predict regrowth and possible further therapy. 

Although there are theoretical advantages to the use of Embospheres, clinical studies have not shown an advantage over PVA particles [27]. The volume decrease ofthe fibroids, and the uterine volume reduction is similar between Embospheres and PVA [54]. The volume of microspheres required for an embolization is larger than the volume of PVA required to complete an embolization [27]. In both retrospective and prospective study there does not seem to be a difference in post procedure pain or the use of narcotic use between PVA and microspheres [27,55]. 

Using three-dimensional color Doppler sonography, Fleischer et al. [36] found that hypervascular fibroids tend to decrease in size after UFE more than their isovascular or hypovascular fibroids. McLu-CAS et al. [15] showed that the initial peak systolic velocity was positively correlated with the shrinkage of fibroids and uterine volume reduction. 

Khaund A, Moss JG, McMillan N, Lumsden MA (2004) Evaluation of the effect of uterine artery embolisation on menstrual blood loss and uterine volume. Br J Obstet Gynaecol 111 700-705... 

Administration of oxytocin may result in fetal bradycardia, uterine rupture, uterine hypertonicity, nausea, vomiting, cardiac arrhythmias, and anaphylactic reactions. Serious water intoxication (fluid overload, fluid volume excess) may occur, particularly when the drug is administered by continuous infusion and the patient is receiving fluids by mouth. When used as a nasal spray, adverse reactions are rare. 

The effects of tamoxifen on uterine leiomyomas have been studied also in postmenopausal patients with breast cancer (Schwartz et al. 1998). After an average treatment of about 1 year, uterine and leiomyoma volumes increased significantly, confirming an agonistic effect of tamoxifen on the uterus. No significant difference in agonist effect on the uterus has been detected between tamoxifen and toremifene (Tomas et al. 1995). 

De Leo V, La Marca A, Morgante G, Severi FM, Petraglia F (2001) Administration of somatostatin analogue reduces uterine and myoma volume in women with uterine leiomyomata. Obstet Gynecol 75 632-633... 

Raloxifene, a more complete uterine antagonist than tamoxifen or clomiphene, significantly reduces leiomyoma size in post-menopausal women [31], yet it is less efficacious at reducing tumor volume in pre-menopausal women [32], This result has been attributed to the poor pharmacokinetic properties of this compound in which extensive conjugative metabolism of the phenol(s) limits the circulating levels of the parent drug. In addition, clinical outcomes in premenopausal women treated with raloxifene suggest that this compound, like tamoxifen and clomiphene, can affect the ovaries via the HPO axis [33]. These data, taken collectively, indicate that current SERMs lack the efficacy, pharmacokinetic, and ovarian safety properties needed to treat leiomyoma in ovulatory women. 

Route of administration The use of oxytocin for the induction of labor requires intravenous administration. According to Micromedex, pulsatile administration achieves the same results as continuous administration with a significantly lower dose and infusion volume. Intravenous infusion of oxytocin is routinely used postpartum to control uterine bleeding. 

Slott and Hales (1985) laparotomized pregnant Sprague-Dawley rats on day 13 of gestation and the uterus was exposed. Each embryo in one uterine horn received an intraamniotic injection of acrylic acid in 0.9% NaCl at doses of up to 1000 Lg per fetus. The contralateral embryos received equivalent volumes of saline. The uterus was repositioned in the dam and the incision sutured. Dams were sacrificed on day 20 of gestation and the fetuses scored for survival, resorptions and external malformations. No significant increase in fetal malformations was observed, although a dose of 1000 (but not 100) j,g per fetus enhanced the number of dead or resorbed fetuses significantly. 

High output left ventricular failure has been described after hysteroscopic lysis of adhesions using dextran as a distension medium. Prolonged surgical dissection of the uterine wall (the precise duration of the operation was not stated in the report) and the large volume of dextran and fluid (2 liters of 5% dextrose and an additional 800 ml of dextran) probably caused the dextran to enter into the systemic circulation, inducing a significant shift of fluid into the intravascular compartment (2). 

The middle uterine, utero-ovarian or external iliac arteries may rupture during pregnancy or parturition, leading to signs of shock and colic or to the death of the mare. The therapy of rupture of these major blood vessels is somewhat controversial and may range from drugs that reduce blood pressure to those that increase circulating blood volume and pressure (Vivrette 1997). 

In the placenta a volume of oxygen sufficient for fetal needs must diffuse across the membranes from maternal to fetal blood during the short time the two circulations are in close contact. This oxygen transfer is a function of several factors which include uterine and umbilical arterial 02 partial pressures, maternal and fetal placental blood flow rates, the 02 capacity and 02 affinity of maternal and fetal hemoglobin, the diffusing capacity of the placenta, the amount of C02 exchanged, and the vascular arrangement of maternal to fetal vessels. 

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