Natalie Greenwold

Trophoblastic oxidative stress in relation to temporal and regional differences in maternal placental blood flow in normal and abnormal early pregnancies

Onset of the maternal-placental circulation was studied by Doppler ultrasonography in 65 pairs of age-matched normal and abnormal pregnancies. In normal pregnancies intervillous blood flow increased with gestational age, being detected in 9 of 25 cases at 8 to 9 weeks but in 18 of 20 at 12 to 13 weeks (P = 0.001). By contrast, in abnormal pregnancies flow was detected in nearly all cases (22 of 25) at 8 to 9 weeks (P < 0.001). In addition, regional differences were observed between the groups. Early flow was restricted to the peripheral regions of most normal placentas (P < 0.001), whereas in missed miscarriages it was most common in central regions or throughout the placenta (P < 0.05 and P < 0.001, respectively). Immunoreactivity for heat shock protein 70 and nitrotyrosine residues was greater in samples from peripheral than from central regions of normal placentas (P = 0.028 and P = 0.019, respectively), and from missed miscarriages compared to controls (P = 0.005 and P = 0.001, respectively). Our results indicate that oxidative damage to the trophoblast, induced by premature and widespread onset of the maternal placental circulation secondary to shallow trophoblast invasion, is a key factor in early pregnancy loss. High oxygen concentrations in the periphery of normal early placentas may similarly induce local regression of the villi, leading to formation of the chorion laeve.

Comparison of ultrasonographic and Doppler mapping of the intervillous circulation in normal and abnormal early pregnancies

OBJECTIVE To assess the value of ultrasonography and Doppler imaging in characterizing the intervillous circulation in normal and abnormal early pregnancy. DESIGN Cross-sectional study. SETTING Tertiary care academic hospital. PATIENT(S) Eighty-five normal pregnancies and 125 missed miscarriages at 7 to 13 weeks of gestation. INTERVENTION(S) Grey-scale ultrasonography was used to evaluate the placental anatomy and detect moving echoes inside the intervillous space, and color power Doppler imaging was used to detect continuous venous-like flow in the placental tissue. MAIN OUTCOME MEASURE(S) Degree of agreement between two investigators for use of grey-scale imaging, comparison of detection of moving echoes in normal and abnormal pregnancies, and comparison of detection of intervillous circulation with grey-scale and color Doppler imaging in abnormal pregnancies. RESULT(S) The overall degree of agreement between the two investigators was good. A significantly different distribution of blood flow was found between normal and abnormal pregnancies at 7 to 9 weeks and 10 to 11 weeks but not at 12 to 13 weeks. Intervillous moving echoes were detected by grey-scale imaging significantly more frequently than an intervillous blood flow was detected with color Doppler imaging. CONCLUSION(S) In early pregnancy failure, there is a premature and diffuse onset of intervillous blood flow that can be detected by grey-scale imaging. This abnormal blood flow pattern may increase the oxidative stress on the early placental tissue and subsequently impair placental development.

Relationship among maternal serum endocrinology, placental karyotype, and intervillous circulation in early pregnancy failure.

OBJECTIVE To evaluate the relationship among maternal serum endocrinology, placental karyotype, and intervillous blood flow in missed miscarriage. DESIGN Cross-sectional study of maternal serum, transvaginal ultrasound/Doppler, and placental cytogenetic and immunohistochemical investigations. SETTING Tertiary care academic hospital. PATIENT(S) One hundred fifty-two women with missed miscarriage between 7 and 13 weeks of gestation. INTERVENTION(S) Ultrasound features, placental intervillous circulation findings on color Doppler imaging, and maternal serum level of alpha-fetoprotein (AFP), beta-hCG, E(2), P, and inhibin A were compared retrospectively with placenta karyotype and hCG immunochemistry. MAIN OUTCOME MEASURES Data were analyzed according to karyotype results, presence or absence of an intervillous circulation, and delay between fetal demise and evacuation. RESULT(S) The presence of intervillous blood flow and serum concentrations of the different hormones were independent of placental karyotype. Serum beta-hCG and P were significantly higher in cases with intervillous blood flow. No difference in immunostaining for beta-hCG was found between placental tissues from normal pregnancies and missed miscarriages, but significantly higher villous beta-hCG content was found on Western blotting in miscarriage with a recent fetal demise. CONCLUSION(S) The excessive entry of maternal blood inside the placenta in the early stage of most miscarriages is unrelated to conceptus karyotype, and hCG features may reflect a temporary attempt of the trophoblast to stabilize after the initial oxidative insult.

Implementing an obstetric ultrasound training program in rural Africa

To evaluate the feasibility and sustainability of basic obstetric ultrasound training in rural Africa.