( 10) have reported that that impedance of spiral artery blood flow in women with unexplained infertility was significantly higher than that of the fertile counterparts. The role of spiral artery hemodynamics in the etiopathogenesis of infertility is well established in literature ( 8, 9). Any defect/deficiency in this normal process is implicated in many of the complications seen in pregnancy, such as early pregnancy failure, preeclampsia, intra-uterine growth restriction (IUGR), small for gestational age (SGA) fetuses. During this process, the wall of the blood vessels, particularly the spiral arteries, are invaded by migrating extravascular trophoblast cells causing their progressive dilatation and delivery of blood to the intervillous space at even low pressures, thus ensuring adequate perfusion at all times. Crucial to this is the normal development of the uteroplacental circulation space in early pregnancy for which successful trophoblastic invasion of the maternal decidua, myometrium and the blood vessels is required ( 2– 5). Successful pregnancy depends upon the unhindered to and fro transfer of oxygen, nutrients and wastes in-between the maternal and fetal compartments. Mechanical index (MI) was 0.82 and thermal index for soft tissues (TIs) was 0.7. The pulsed Doppler sample volume was set at a width of 2 mm. Flow velocity waveforms were obtained by placing the Doppler gate over the colored areas and activating the pulsed-wave Doppler function. Spiral arteries just beneath the chorion frondosum were assessed by power Doppler imaging (Fig. Uterine spiral arteries were assessed by triplex mode examination (gray scale image combined with color Doppler and a flow spectrum on the spectral wave). After gently inserting the trans-vaginal probe into the vagina, the uterus and adnexae were scanned to confirm the presence of intrauterine gestational sac. The purpose of this study was to demonstrate whether the possible modifications in blood flow patterns in spiral arteries can be picked up on trans-vaginal Doppler sonography and to investigate whether these Doppler findings could predict adverse pregnancy outcomes.Īll sonographic procedures were performed using a Siemens Acuson X300 ultrasound machine (Siemens Ultrasound, Munich, Germany) equipped with a real time 6.0 MHz endovaginal probe.īefore the examination, the women were asked to empty their urinary bladder. It is now widely accepted that the most common complications of pregnancy arise due to abnormalities in early trophoblast invasion and persistently increased resistance of the spiral arteries ( 2– 5). Impaired vascular remodeling in the maternal fetal interface is one of the most important factors associated with early and late complications in pregnancy ( 3, 5– 7). The ability of trans-vaginal Doppler sonography to analyze the pattern of circulation in even terminal branches of the uteroplacental circulation has encouraged research for its potential application in predicting early and late pregnancy complications related to abnormal placentation. The introduction of high-frequency transvaginal color Doppler ultrasonography with spectral analysis has allowed evaluation of uteroplacental circulation in early pregnancy, abnormalities of which have been linked to pregnancy complications such as hypertension, intrauterine growth restriction (IUGR), fetal distress, and early pregnancy failure ( 2– 4). Due to the high prevalence of spontaneous miscarriage in this group of patients, a method that could predict pregnancy outcome in early gestation would be of great clinical advantage. Even women with threatened abortion and a living embryo have increased chances of pregnancy loss up-to 15% when compared with general population ( 1, 2). About 1/5 of all pregnant females present with symptoms of threatened abortion in the first trimester and almost half of the women with threatened abortion result in pregnancy loss ( 1). This bleeding may or may not be associated with abdominal pain. Threatened miscarriage is a clinical term for vaginal bleeding that occurs during the first 20 weeks of pregnancy where fetus is clinically supposed to be alive.
0 kommentar(er)
