Placental Development in Normal and Compromised Pregnancies— A Review

Regnault, Timothy R. H.; Galan, Henry L.; Parker, Thomas A.; Anthony, Russell V.

doi:10.1053/plac.2002.0792

Cited by 237 publications

(168 citation statements)

References 82 publications

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“…Experimental IUGR IUGR can be induced in ewes by various means, including manipulation of maternal nutrition, administration of glucocorticoids, artificial restriction of placental size, creation of uteroplacental embolisms, and exposure of pregnant ewes to extreme environmental conditions, such as high temperature and low oxygen pressure (McMillen et al, 2001;Regnault et al, 2002;Redmer et al, 2004;Fowden et al, 2006c;Wallace et al, 2006). Interestingly, such simple practices as shearing ewes during mid or late pregnancy can increase lamb BWTs (Symonds et al, 1992;Revell et al, 2000;Kenyon et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Litter-size-dependent intrauterine growth restriction in sheep

Gootwine

Spencer

Bazer

2007

Animal

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Regulation of foetal development in sheep depends on interactions between the intrinsic capacity of the foetus for growth and the maternal environment. Lambs born in multi-foetus litters have relatively small placentae with fewer cotelydons, and lower birth weights. Litter-size-dependent intrauterine growth restriction (IUGR) is evident at mid gestation when metabolic needs of the conceptus are moderate, and overnutrition of ewes with multiple foetuses does not promote growth of their foetuses to the size of singletons. Those observations suggest that placental and conceptus growth in multi-foetus pregnancies is reprogrammed at mid gestation by an as yet undefined mechanism to attenuate foetal growth. This may protect the foetus from severe nutritional insult during late gestation, when its daily growth rate is at a maximum. In that way, lambs born in large litters with relatively lower birth weights may not experience the long-term physiological insults that can be observed in small lambs born to undernourished ewes.

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Section: Introductionmentioning

confidence: 99%

Litter-size-dependent intrauterine growth restriction in sheep

Gootwine

Spencer

Bazer

2007

Animal

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“…O grau III placentário também se associa a óbito perinatal 2,[4][5][6][7][8]11 . Esse achado foi observado em sete (4,8%) casos, seis (85,7%) dos quais em gestações complicadas com pré-eclâmpsia, oligoâmnio e RCIU, e um (14,3%), em ausência de complicações clínico-obstétricas.…”

Section: Características Ao Nascimentounclassified

“…A associação entre calcificação placentária e idade gestacional tem sido observada desde os primeiros estudos ultra-sonográficos sobre a placenta 1,3 . Fato importante consiste na relação entre a calcificação placentária precoce (grau II e grau III placentário anterior à 32ª e 35ª semana de gestação, respectivamente) e a possibilidade de desenvolvimento de restrição de crescimento intra-uterino (RCIU) [4][5][6] , causa freqüente de morbidade e mortalidade perinatal 2 . Quando se observou ocorrência mais comum de placenta grau III prematura em gestantes hipertensas e com RCIU, foi sugerido que o aparecimento precoce de sonolucências e de calcificações na placenta pode representar disfunção ou senescência placentária e não maturação fisioló-gica 7 .…”

Section: Introductionunclassified

Amadurecimento precoce da placenta avaliada pela ultra-sonografia e prognóstico perinatal

Queiroz¹,

Costa²

2006

Rev. Bras. Ginecol. Obstet.

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Objetivo: descrever os resultados maternos e perinatais das gestações com amadurecimento precoce da placenta detectado pela ultra-sonografia. Métodos: realizou-se estudo retrospectivo, descritivo, tipo série de casos, com comparação de grupos. Foram incluídas 146 gestantes, internadas entre janeiro de 2000 e dezembro de 2002 e em cujo prontuário constavam diagnóstico de amadurecimento precoce da placenta (presença de placenta grau II antes da 32ª semana de gestação ou grau III, antes da 35ª semana de gestação) e descrição das condições materno-fetais. Foram excluídas gestantes com diagnóstico de: amniorrexe prematura, gravidez múltipla, forma aguda de descolamento prematuro de placenta normoinserida e malformação fetal. As complicações clínico-obstétricas foram: doenças hipertensivas, redução do crescimento intra-uterino, alterações do volume de líquido amniótico, infecções, diabete materno, anemia falciforme, soropositividade para HIV, drogadição, litíase renal, epilepsia e asma brônquica. Pelos prontuários, foram identificadas 106 gestantes com complicações clínico-obstétricas (Gcom) e 40, sem essas complicações (Gsem). Para comparação entre os grupos, empregaram-se os testes de χ 2 e exato de Fisher, ao nível de significância de 0,05. Resultados: o grupo Gcom apresentou maior freqüência de oligoâmnio (27,3%), restrição de crescimento intra-uterino (44,3%) e cesárea antecedente ao trabalho de parto (36,8%). Comparado ao grupo Gsem, o Gcom caracterizou-se por maior incidência de óbitos fetais, prematuros (58,8 versus 40%), menor índice de Apgar de 5º minuto, peso ao nascer <2.500 g (67,9 versus 40%), recém-nascidos pequenos para a idade gestacional (39,2 versus 10%) e intercorrências mais graves. Conclusões: o prognóstico perinatal não dependeu do amadurecimento precoce da placenta, mas sim da presença de complicações clínico-obstétricas maternas. PALAVRAS-CHAVE:Placenta; Ultrasonografia pré-natal; Prognóstico ABSTRACT Purpose: to describe perinatal and obstetric characteristics of pregnant women with ultrasonographic early placental aging. Methods: using a retrospective, descriptive, series of cases, with group comparison, the authors analyzed the data of 146 pregnant women, whose diagnosis of placental early aging (presence of grade II placenta before 32 gestational weeks or grade III, before 35 gestational weeks), and maternal-fetal conditions had been recorded in the medical charts at the "Maternidade Prof. Monteiro de Moraes", Recife, Pernambuco -Brazil, from January 2000 to December 2002, where they had been attended as inpatients. The exclusion criteria were diagnoses of: premature amniorrhexis, multiple pregnancies, acute premature detachment of a normally located placenta, and fetal malformation. The clinical and obstetric complications were: hypertensive diseases, intrauterine growth restriction, changes of amniotic fluid volume, infections, maternal diabetes, falciform anemia, HIV seropositivity, drug addiction, renal lithiasis, epilepsy and bronchial asthma. In the medical records, 106 pregnant wome...

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“…The placenta is a multifunctional organ essential for maintaining pregnancy, providing nutrients and growth factors to the fetus, removing waste and protecting the fetus from potentially harmful substances [1]. Placental dysfunction can result in insufficient fetal nutrition, which can lead to intrauterine growth restriction (IUGR) [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…Epidemiological studies indicate IUGR can have lifelong consequences by increasing the risk for heart disease, type-2 diabetes, hypertension, and stroke [9][10][11][12]. Abnormalities in placental structure and function have been associated with the majority of reported cases of fetal IUGR [1].…”

Section: Introductionmentioning

confidence: 99%

Placental Defects in α7 Integrin Null Mice

et al. 2007

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The α7β1 integrin is a heterodimeric transmembrane receptor that links laminin in the extracellular matrix to the cell cytoskeleton. Loss of the α7 integrin chain results in partial embryonic lethality. We have previously shown that α7 integrin null embryos exhibit vascular smooth muscle cell defects that result in cerebral vascular hemorrhaging. Since the placenta is highly vascularized, we hypothesized that placental vascular defects in α7 integrin null embryos may contribute to the partial embryonic lethality. Placentae from embryonic day (ED) 9.5 and 13.5 α7 integrin knockout embryos showed structural defects including infiltration of the spongiotrophoblast layer into the placental labyrinth, a reduction in the placental labyrinth and loss of distinct placental layers. Embryos and placentae that lacked the α7 integrin weighed less compared to wild-type controls. Blood vessels within the placental labyrinth of α7 integrin null embryos exhibited fewer differentiated vascular smooth muscle cells compared to wild-type. Loss of the α7 integrin resulted in altered extracellular matrix deposition and reduced expression of α5 integrin. Together our results confirm a role for the α7β1 integrin in placental vascular development and demonstrate for the first time that loss of the α7 integrin results in placental defects.

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Placental Development in Normal and Compromised Pregnancies— A Review

Cited by 237 publications

References 82 publications

Litter-size-dependent intrauterine growth restriction in sheep

Litter-size-dependent intrauterine growth restriction in sheep

Amadurecimento precoce da placenta avaliada pela ultra-sonografia e prognóstico perinatal

Placental Defects in α7 Integrin Null Mice

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