A Sonographic Assessment of Different Patterns of Placenta Previa ???Migration??? in the Third Trimester of Pregnancy

Abstract

Preeclampsia has been associated with an increased risk of cardiovascular disease and also with a lowered risk of breast cancer later in life. These associations may represent underlying metabolic changes. The investigators undertook a case-control study in which metabolic profiles were examined in women who completed their pregnancies at age 30 and older and had no serious chronic disorders. Thirteen women had experienced preeclampsia in their first pregnancies, whereas 13 others had no complications. Preeclampsia was defined as newly developed hypertension of pregnancy exceeding 140/90 mm Hg and proteinuria of at least 0.3 g/24 hours. The groups were matched for race/ethnicity, current age at the time of delivery, and current age.Women having preeclampsia were likelier than control women to be primiparous, tended to be heavier, and had higher resting diastolic blood pressure. There were no significant group differences in age at first delivery, age at first menses, current age, racial/ethnic distribution, a history of breast feeding, or a family history of breast cancer. In the overall group, body mass index correlated positively with serum levels of triglycerides, insulin, and glucose as well as with the fasting insulin resistance index. Women with a history of preeclampsia had significantly higher levels of fasting serum triglycerides, insulin, and glucose, and lower levels of fasting high-density lipoprotein than women without complications. In addition, they had a higher fasting insulin resistance index. A history of preeclampsia correlated with increased levels of insulin-like growth factor-binding protein-3 (IGFBP-3) and a higher ratio of IGFBP-3 to IGF-1 (insulin-like growth factor-1). Controlling for obesity did not substantially alter these associations. Adjusting for obesity or parity did not significantly alter the relationship between past preeclampsia and markers of dyslipidemia or reduced levels of IGF-1. No major differences emerged after excluding obese women. The case and control women had comparable fasting serum levels of total cholesterol and IGF-1.In women having preeclampsia in a former pregnancy, reduced bioavailability of IGF-1, relative insulin resistance, and dyslipidemia may persist. These changes may account, at least in part, for the increased risk of cardiovascular disease as well as the lowered risk of breast cancer observed in these women. ABSTRACTAlthough immediate termination of pregnancy in cases of preeclampsia does benefit the mother, it often is not in the best interest of the fetus, especially if carried out long before term. A program of temporizing management has been adopted for use in severe early-onset preeclampsia, the goal being to correct maternal hemodynamics through plasma expansion and pharmacologic vasodilatation. Short-term benefit has been demonstrated with this approach. The question of whether this benefit is sustained was examined in 222 consecutive infants who lived at least 12 months and whose mothers had severe preeclampsia (diastolic blood pressure of ...

Placental Migration and Its Role in Prediction of Route of Delivery

“…In contrast, those placentas previa that yielded a placental distance from the internal cervical os of more than 3.0 cm at final examination had a mean rate of migration of 4.1 mm/wk. A slower rate of placental migration was directly related to a lesser placental distance from the internal cervical os [8,[13][14][15]. These findings are similar to those of a previous report in which the mean rates of placental migration were 0.3 and 5.4 mm/ wk for those patients who had CD versus normal vaginal delivery, respectively [5,7,[9][10].…”

“…The location of the placenta and proximity of the placental edge to the internal cervical os was evaluated as a standard TVUS examination during the third trimester [8][9][10]. We regarded a placenta located within 30 mm of the internal os after 30 weeks' gestation as low-lying [6].Cases with a low-lying placenta were tagged prospectively during performance of the examination, and were subsequently reviewed for this study.…”

Placenta and Transvaginal Sonography

“…1 It is also now clear that changes in placental location occur throughout gestation and are consequent to two phenomena, formation of the lower uterine segment and placental trophotropism. 11,15,16 Trophotropism is the term used to describe preferential proliferation of trophoblastic villi in regions of better endometrial supply along with atrophy of villi in areas with a poorer blood supply. 15,16 Placental position and shape can, therefore, change as pregnancy progresses.…”

“…11,15,16 Trophotropism is the term used to describe preferential proliferation of trophoblastic villi in regions of better endometrial supply along with atrophy of villi in areas with a poorer blood supply. 15,16 Placental position and shape can, therefore, change as pregnancy progresses. Trophotropism explains resolution of placenta previa, increase in pathologic extent of placenta previa, the development of succenturiate lobes or a bilobed placenta, odd-shaped placentas and abnormal cord insertions.…”

ACR Appropriateness Criteria® Second and Third Trimester Bleeding

“…This is usually evaluated by transabdominal examination of the cervix and lower uterine segment with the bladder moderately full; however, the bladder should not be so full as to artificially elongate the cervix. 27 When the placenta fully covers the cervix and is implanted on both the anterior and posterior walls of the lower-uterine segment, by an overlap of 915 mm as seen on the initial scan at 18 to 23 weeks, there is a high likelihood of resultant delivery by Caesarean section. 18 One study found that scanning at 20 to 23 weeks decreased the number of false positives 19 ; however, most practitioners perform the anatomic survey at 18 to 20 weeks to allow for counseling and additional testing as needed.…”