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OBJECTIVE: To compare maternal vascular indices and hemodynamic parameters at 35-37 weeks' gestation, in pregnancies complicated by small for gestational age (SGA) fetuses and those with fetal growth restriction (FGR). METHODS: This was a prospective observational non-intervention study in women with singleton pregnancies attending for a routine hospital visit at 35+0 to 36+6 weeks' gestation. The visit included recording of maternal demographic characteristics and medical history, vascular indices and hemodynamic parameters obtained by a non-invasive operator independent device, including pulse wave velocity, augmention index, cardiac output, stroke volume, central systolic and diastolic blood pressure, total peripheral resistance and fetal heart rate. Hypertensive disorders of pregnancy were excluded and the values in the SGA and FGR groups were compared between them and with unaffected pregnancies. Diagnosis of SGA was based on the birth of a baby with birthweight below the 10th percentile for gestational age. In FGR, in addition to a birthweight below the 10th percentile, at the 35-37 weeks scan Doppler studies had shown that the uterine artery or umbilical artery pulsatility index (PI) was above the 95th percentile for gestational age or the fetal middle cerebral artery PI was below the 5th percentile. RESULTS: In the 6,413 women included in the study there were 605 (9.4%) cases of SGA, 133 (2.1%) of FGR and 5,675 (88.5%) unaffected by SGA or FGR. Women with SGA or FGR, compared to unaffected pregnancies, had increased peripheral vascular resistance and reduced cardiac output. Central systolic and diastolic blood pressure were also increased, whereas aortic stiffness assessed by pulse wave velocity and augmentation index did not differ between affected and unaffected pregnancies. In the FGR, compared to the SGA group, central systolic and diastolic blood pressure were higher, whereas, heart rate was lower. CONCLUSIONS: In SGA and FGR pregnancies there are deranged maternal hemodynamic responses when these are compared to normal pregnancies. Mothers with FGR babies have higher central blood pressure compared to SGA ones, but it remains unclear whether these differences are driven by the size of the fetus or pathological fetal growth. This article is protected by copyright. All rights reserved.
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OBJECTIVE: To investigate whether angiogenic markers of placental function are associated with maternal cardiac function and hemodynamic responses at 19-23 weeks' gestation, controlling for maternal risk factors and pregnancy complications. METHODS: This was a prospective study of women with singleton pregnancy attending King's College Hospital, London, UK, for a routine hospital visit at 19-23 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure (MAP), maternal heart rate, serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). We also performed maternal echocardiography to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function. RESULTS: Our cohort included 4006 women. Lower PlGF values were significantly associated with higher MAP (P < 0.0001), lower maternal heart rate (P < 0.0001), lower mitral valve s' mean velocity (P = 0.027) and higher left atrial area (P = 0.022) after adjustment for maternal characteristics and pregnancy complications. sFlt-1 was associated positively with relative wall thickness (P = 0.012), whereas sFlt-1/PlGF ratio was associated negatively with mitral valve A (P = 0.006) and positively with left atrial area (P = 0.015) and MAP (P = 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors based on their obstetric and medical history. CONCLUSIONS: A continuous association of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present in midgestation, independently of pre-existing maternal risk factors and pregnancy complications. Impaired placental function appears to be related to mild systolic and diastolic dysfunction and cardiac remodeling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.
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Melting and premelting phenomena in self-organized organic systems have been extensively explored in the literature, exploring distinct behaviors of different molecule lengths and morphologies. Nevertheless, the influence of the supramolecular assembly configuration on the occurrence of premelting remains poorly explored. Here we use phosphonic acids as model systems for self-organized molecular assemblies. These molecules exhibit long-range order on different types of substrates. The balance between chain-to-chain and head-to-head interactions leads to distinct types of stackings. Although their structural configurations are well understood, very little is known about their behavior near the melting transition. We show here that premelting occurs in lamellar structures and that its behavior depends directly on the ordered configuration assumed in the studied multilayers. Two molecules with different chain lengths were investigated: octadecyl phosphonic and octyl phosphonic acids. Although almost no dependence on the molecule length was observed, the occurrence of premelting is strongly influenced by their lamellar packing configuration. For tilted packings premelting is unfavored while in straight configurations, where alkyl chain interactions are weakened with respect to head-to-head interactions, strong premelting is observed. We find that the onset of premelting occurs at the domain boundaries with straight lamellar configurations and the domain sizes exhibit power law temperature dependences.
