Metodologia para estudo do volume e densidade absoluta da placenta humana de termo

Nero, Ulisses Del; Rudge, Marilza Vieira Cunha; Novo, Neil Ferreira; Calderon, Iracema de Mattos Paranhos; Brasil, Maria Aparecida Mourão

doi:10.1590/s0100-72032002001000006

Cited by 5 publications

(2 citation statements)

References 3 publications

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“…Several changes occur in the human placenta during pregnancies that are complicated by DM. These abnormalities are directly associated with intrauterine blood glucose levels that lead to reduced maternal-placental blood circulation and maternal-fetal exchange ( 11 ). Both macroscopic and microscopic pathological changes are associated with complications during pregnancy.…”

Section: Discussionmentioning

confidence: 99%

Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

Salge¹,

Rocha²,

Xavier³

et al. 2012

Clinics

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OBJECTIVES:The current study sought to identify macroscopic placental changes associated with clinical conditions in women with or without diabetes and their newborns.METHODS:The study population consisted of 62 pregnant women clinically diagnosed with diabetes and 62 healthy women (control group).RESULTS:Among the subjects with diabetes, 43 women (69.3%) were diagnosed with gestational diabetes mellitus, 15 had diabetes mellitus I (24.2%), and four had diabetes mellitus II (6.5%). The mean age of the women studied was 28.5±5.71 years, and the mean gestational age of the diabetic women was 38.51 weeks. Of the 62 placentas from diabetic pregnancies, 49 (79%) maternal surfaces and 59 (95.2%) fetal surfaces showed abnormalities, including calcium and fibrin deposits, placental infarction, hematoma, and fibrosis. A statistical association was found between newborn gender and fetal and maternal placental changes (p = 0.002). The mean weight of the newborns studied was 3,287±563 g for women with diabetes mellitus, 3,205±544 g for those with gestational diabetes mellitus, 3,563±696 g for those with diabetes mellitus II, and 3,095±451 g for those with diabetes mellitus I.CONCLUSIONS:Infarction, hematoma, calcification, and fibrin were found on the maternal and fetal placental surfaces in women with diabetes. Women with gestational diabetes and post-term infants had more calcium deposits on the maternal placental surface as compared to those with type I and type II diabetes.

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Section: Discussionmentioning

confidence: 99%

Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

Salge¹,

Rocha²,

Xavier³

et al. 2012

Clinics

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“…Here, we have assumed that the products of conception appear at gestational age 2 weeks, and that the densities of the placenta and amniotic fluid are 1.02 g/mL [53] and 1.01 g/mL [54], respectively (cf. Table 8).…”

Section: Resultsmentioning

confidence: 99%

Empirical models for anatomical and physiological changes in a human mother and fetus during pregnancy and gestation

et al. 2019

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Many parameters treated as constants in traditional physiologically based pharmacokinetic models must be formulated as time-varying quantities when modeling pregnancy and gestation due to the dramatic physiological and anatomical changes that occur during this period. While several collections of empirical models for such parameters have been published, each has shortcomings. We sought to create a repository of empirical models for tissue volumes, blood flow rates, and other quantities that undergo substantial changes in a human mother and her fetus during the time between conception and birth, and to address deficiencies with similar, previously published repositories. We used maximum likelihood estimation to calibrate various models for the time-varying quantities of interest, and then used the Akaike information criterion to select an optimal model for each quantity. For quantities of interest for which time-course data were not available, we constructed composite models using percentages and/or models describing related quantities. In this way, we developed a comprehensive collection of formulae describing parameters essential for constructing a PBPK model of a human mother and her fetus throughout the approximately 40 weeks of pregnancy and gestation. We included models describing blood flow rates through various fetal blood routes that have no counterparts in adults. Our repository of mathematical models for anatomical and physiological quantities of interest provides a basis for PBPK models of human pregnancy and gestation, and as such, it can ultimately be used to support decision-making with respect to optimal pharmacological dosing and risk assessment for pregnant women and their developing fetuses. The views expressed in this article are those of the authors and do not necessarily represent the views or policies of the U . S . Environmental Protection Agency .

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Placental Growth during Normal Pregnancy - A Magnetic Resonance Imaging Study

Langhoff¹,

Grønbeck²,

Huth³

et al. 2016

Gynecol Obstet Invest

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Objective: To investigate normal human placental growth longitudinally throughout the second and third trimesters using MRI. Methods: Twenty normal, first-time singleton pregnancies were scanned 7 times between the 14th and 38th week of gestation, at 4-week intervals, using MRI. Placental volumes were measured in both sagittal and transversal slices. All placentas were weighed after delivery to make a comparative study. Results: Sixteen of the 20 women had increasing placental volumes from the 14th to 38th week of gestation. The 6th and 7th scan showed that 4 women had placentas of the same size. The mean placental volume increases linearly from the 14th till the 38th week of gestation, with a constant mean growth rate of 29.97 ml/week. The median placental volume extrapolated to delivery was to 856 ml (range 602-1,050 ml). The median weight of the exsanguinated placenta after delivery was 640 g (range 500-787 g). All pregnancies were carried to term, resulting in the delivery of healthy infants with good correlation between placental size and birth weight (R = 0.56, p = 0.009). Conclusion: Placental growth was measured systematically in a longitudinal study through the second and third trimesters using MRI. MRI provides a safe and feasible method to measure placental growth. The mean placental growth was linear throughout the second and third trimesters.

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Metodologia para estudo do volume e densidade absoluta da placenta humana de termo

Cited by 5 publications

References 3 publications

Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus

Empirical models for anatomical and physiological changes in a human mother and fetus during pregnancy and gestation

Placental Growth during Normal Pregnancy - A Magnetic Resonance Imaging Study

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