As pregnancy is a physiological prothrombotic state, pregnant women may be at increased risk of developing coagulopathic and/or thromboembolic complications associated with COVID-19.
Two biomedical ...databases were searched between September 2019 and June 2020 for case reports and series of pregnant women with a diagnosis of COVID-19 based either on a positive swab or high clinical suspicion where no swab had been performed. Additional registry cases known to the authors were included. Steps were taken to minimise duplicate patients. Information on coagulopathy based on abnormal coagulation test results or clinical evidence of disseminated intravascular coagulation (DIC), and on arterial or venous thrombosis, were extracted using a standard form. If available, detailed laboratory results and information on maternal outcomes were analysed.
One thousand sixty-three women met the inclusion criteria, of which three (0.28, 95% CI 0.0 to 0.6) had arterial and/or venous thrombosis, seven (0.66, 95% CI 0.17 to 1.1) had DIC, and a further three (0.28, 95% CI 0.0 to 0.6) had coagulopathy without meeting the definition of DIC. Five hundred and thirty-seven women (56%) had been reported as having given birth and 426 (40%) as having an ongoing pregnancy. There were 17 (1.6, 95% CI 0.85 to 2.3) maternal deaths in which DIC was reported as a factor in two.
Our data suggests that coagulopathy and thromboembolism are both increased in pregnancies affected by COVID-19. Detection of the former may be useful in the identification of women at risk of deterioration.
Severe pre-eclampsia can cause significant mortality and morbidity for both mother and child, particularly when it occurs remote from term, between 24 and 34 weeks' gestation. The only known cure for ...this disease is delivery. Some obstetricians advocate early delivery to ensure that the development of serious maternal complications, such as eclampsia (fits) and kidney failure are prevented. Others prefer a more expectant approach delaying delivery in an attempt to reduce the mortality and morbidity for the child associated with being born too early.
The objective of the review was to compare the effects of a policy of interventionist care and early delivery with a policy of expectant care and delayed delivery for women with early onset severe pre-eclampsia.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2013).
Randomised trials comparing the two intervention strategies for women with early onset severe pre-eclampsia.
Two review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. Data were checked for accuracy.
Four trials, with a total of 425 women are included in this review. Trials were at low risk of bias for methods of randomisation and allocation concealment; high risk for blinding; unclear risk for incomplete outcome data and other bias; and low risk for selective reporting. There are insufficient data for reliable conclusions about the comparative effects on most outcomes for the mother. For the baby, there is insufficient evidence for reliable conclusions about the effects on stillbirth or death after delivery (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.69 to 1.71; four studies; 425 women). Babies whose mothers had been allocated to the interventionist group had more intraventricular haemorrhage (RR 1.82, 95% CI 1.06 to 3.14; one study; 262 women), more hyaline membrane disease (RR 2.30, 95% CI 1.39 to 3.81; two studies; 133 women), require more ventilation (RR 1.50, 95% CI 1.11 to 2.02; two studies; 300 women) and were more likely to have a lower gestation at birth in days (average mean difference (MD) -9.91, 95% CI -16.37 to -3.45; four studies; 425 women), more likely to be admitted to neonatal intensive care (RR 1.35, 95% CI 1.16 to 1.58) and have a longer stay in the neonatal intensive care unit (average MD 11.14 days, 95% CI 1.57 to 20.72 days; two studies; 125 women) than those allocated an expectant policy. Nevertheless, babies allocated to the interventionist policy were less likely to be small-for-gestational age (RR 0.30, 95% CI 0.14 to 0.65; two studies; 125 women). Women who had been allocated to the interventionist group were more likely to have a caesarean section (RR 1.09, 95% CI 1.01 to 1.18; four studies; 425 women) than those allocated an expectant policy. There were no statistically significant differences between the two strategies for any other outcomes.
This review suggests that an expectant approach to the management of women with severe early onset pre-eclampsia may be associated with decreased morbidity for the baby. However, this evidence is based on data from only four trials. Further large trials are needed to confirm or refute these findings and establish if this approach is safe for the mother.
Unlike catalytic reactions thermally driven by metal nanoparticles, reaction rates in photocatalysis do not scale with either the density of nanoparticles or their size. Because of the complexity of ...multicomponent photocatalysts in powder form, this lack of correlation, routinely observed for decades, is still not understood. In order to explore this phenomenon, H2 production from ethanol over Au clusters with different coverages deposited on single-crystal rutile TiO2(110) were studied by scanning tunneling microscopy and online mass spectrometry. There is a nonlinear increase of the H2 production with increasing gold coverage. The key determining factor appears to be the Au intercluster distance. Increasing this distance resulted in an increase in the normalized production. These results are explained in terms of competition between clusters for excited electrons to reduce H+ (of surface OH groups) to H2. It was possible to determine the proportionality factor between the hydrogen production and the number of absorbed photons. A slope close to 1 is found, which is in line with the “current doubling effect” in electrocatalysis. Moreover, pump probe transient absorption spectroscopy measurements were conducted. The results show that excited electrons transfer from the conduction band of TiO2 to Au particles within the first picoseconds after UV excitation. The fact that Au metal intercluster distances directly affect the reaction rate indicates that there is an optimum arrangement between the metal and the semiconductor that could potentially be achieved by nanostructuring.
Surface X-ray diffraction has been employed to quantitatively determine the geometric structure of an X-ray-induced superhydrophilic rutile-TiO2(110)(1 × 1) surface. A scatterer, assumed to be ...oxygen, is found at a distance of 1.90 ± 0.02 Å above the five-fold-coordinated surface Ti atom, indicating surface hydroxylation. Two more oxygen atoms, situated further from the substrate, are also included to achieve the optimal agreement between experimental and simulated diffraction data. It is concluded that these latter scatterers are from water molecules, surface-localized through hydrogen bonding. Comparing this interfacial structure with previous studies suggests that the superhydophilicity of titania is most likely to be a result of the depletion of surface carbon contamination coupled to extensive surface hydroxylation.
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•Ethanol Photocatalytic reactions over TiO2(1 1 0) are studied by STM, XPS and mass spectrometry.•PO2 directly impacts the reaction selectivity.•At high PO2 carbon-carbon bond ...cleavage occurs resulting in methyl radicals formation.•Methyl formation correlates with that of formate species.•At low PO2 ethoxides are mainly dehydrogenated to acetaldehyde.
Photocatalytic oxidation of ethanol over rutile TiO2(1 1 0) in the presence of O2 have been studied with scanning tunneling microscopy and on-line mass spectrometry to elucidate the reaction mechanisms. The O2 partial pressure has a direct impact on CC bond cleavage, resulting in a shift of selectivity in gas phase products from acetaldehyde (dehydrogenation) to methyl radicals (CC bond dissociation) with increasing pressure. This differs from the behavior of anatase TiO2(1 0 1) single crystal, where at all investigated pressures negligible CC bond dissociation occurs. The prevalence of the methyl radical species at high oxygen pressures is correlated with an increase in the surface population of an adsorbed species bound to Ti5c after the reaction, which are identified as formate moieties. Parallel XPS C1s, Ti2p and O1s further confirmed the assignment of surface population, by STM, to ethoxides at 300 K, in dark conditions (C1s at 286.7 and 285.4 eV attributed to CH2O and CH3 groups respectively). After photoreaction, a large fraction of the surface was covered by formates (XPS C1 at 289.7 eV). This also correlated with the STM assignment where species spaced by 6 Å along the 0 0 1 direction and with a height of ca. 1.1 Å attributed to formates. Moreover the profile for CH3 radical desorption in the gas phase as a function O2 partial pressures correlated with the increasing surface population of formates. Analysis of the rate of methyl radical formation reveals fast and slow regimes, with photoreaction cross-sections between 10−17 cm2 and 10−19 cm2. The parallel channel of acetaldehyde production has a non-varying cross-section of ca. 2 × 10−19 cm2. A schematic description of the two different reaction channels (dehydrogenation and CC bond dissociation) is given and discussed.
Summary Background Preterm pre-labour ruptured membranes close to term is associated with increased risk of neonatal infection, but immediate delivery is associated with risks of prematurity. The ...balance of risks is unclear. We aimed to establish whether immediate birth in singleton pregnancies with ruptured membranes close to term reduces neonatal infection without increasing other morbidity. Methods The PPROMT trial was a multicentre randomised controlled trial done at 65 centres across 11 countries. Women aged over 16 years with singleton pregnancies and ruptured membranes before the onset of labour between 34 weeks and 36 weeks and 6 days weeks who had no signs of infection were included. Women were randomly assigned (1:1) by a computer-generated randomisation schedule with variable block sizes, stratified by centre, to immediate delivery or expectant management. The primary outcome was the incidence of neonatal sepsis. Secondary infant outcomes included a composite neonatal morbidity and mortality indicator (ie, sepsis, mechanical ventilation ≥24 h, stillbirth, or neonatal death); respiratory distress syndrome; any mechanical ventilation; and duration of stay in a neonatal intensive or special care unit. Secondary maternal outcomes included antepartum or intrapartum haemorrhage, intrapartum fever, postpartum treatment with antibiotics, and mode of delivery. Women and caregivers could not be masked, but those adjudicating on the primary outcome were masked to group allocation. Analyses were by intention to treat. This trial is registered with the International Clinical Trials Registry, number ISRCTN44485060. Findings Between May 28, 2004, and June 30, 2013, 1839 women were recruited and randomly assigned: 924 to the immediate birth group and 915 to the expectant management group. One woman in the immediate birth group and three in the expectant group were excluded from the primary analyses. Neonatal sepsis occurred in 23 (2%) of 923 neonates whose mothers were assigned to immediate birth and 29 (3%) of 912 neonates of mothers assigned to expectant management (relative risk RR 0·8, 95% CI 0·5–1·3; p=0·37). The composite secondary outcome of neonatal morbidity and mortality occurred in 73 (8%) of 923 neonates of mothers assigned to immediate delivery and 61 (7%) of 911 neonates of mothers assigned to expectant management (RR 1·2, 95% CI 0·9–1·6; p=0·32). However, neonates born to mothers in the immediate delivery group had increased rates of respiratory distress (76 8% of 919 vs 47 5% of 910, RR 1·6, 95% CI 1·1–2·30; p=0·008) and any mechanical ventilation (114 12% of 923 vs 83 9% of 912, RR 1·4, 95% CI 1·0–1·8; p=0·02) and spent more time in intensive care (median 4·0 days IQR 0·0–10·0 vs 2·0 days 0·0–7·0; p<0·0001) compared with neonates born to mothers in the expectant management group. Compared with women assigned to the immediate delivery group, those assigned to the expectant management group had higher risks of antepartum or intrapartum haemorrhage (RR 0·6, 95% CI 0·4–0·9), intrapartum fever (0·4, 0·2–0·9), and use of postpartum antibiotics (0·8, 0·7–1·0), and longer hospital stay (p<0·0001), but a lower risk of caesarean delivery (RR 1·4, 95% CI 1·2–1·7). Interpretation In the absence of overt signs of infection or fetal compromise, a policy of expectant management with appropriate surveillance of maternal and fetal wellbeing should be followed in pregnant women who present with ruptured membranes close to term. Funding Australian National Health and Medical Research Council, the Women's and Children's Hospital Foundation, and The University of Sydney.
Despite the proven properties of the anatase phase of TiO2 related to photocatalysis, detailed mechanistic information regarding a photooxidation reaction has not yet been derived from single-crystal ...studies. In this work, we have studied the photooxidation of ethanol (as a prototype hole-scavenger organic molecule) adsorbed on the anatase TiO2(101) surface by STM and online mass spectrometry to determine the adsorbate species in the dark and under UV illumination in the presence of O2 and to extract kinetic reaction parameters under photoexcitation. The reaction rate for the photooxidation of ethanol to acetaldehyde was found to depend on the O2 partial pressure and surface coverage, where the order of the reaction with respect to O2 is close to 0.15. Carbon–carbon bond dissociation leading to the formation of CH3 radicals in the gas phase was found to be a minor pathway, which is contrary to the case of the rutile TiO2(110) single crystal. Our STM images distinguished two types of surface adsorbates upon ethanol exposure that can be attributed to its molecular and dissociative modes. A mixed adsorption is also supported by our DFT calculations, in which we determined similar energies of adsorption (E ads) for the molecular (1.11 eV) and dissociative (0.93 eV) modes. Upon UV exposure at (and above) 3 × 10–8 mbar O2, a third species was identified on the surface as a reaction product that can be tentatively attributed to acetate/formate species on the basis of C 1s XPS results. The kinetics of the initial oxidation steps were evaluated using the STM and mass spectrometry data.
Background
Severe pre‐eclampsia can cause significant mortality and morbidity for both mother and child, particularly when it occurs remote from term, between 24 and 34 weeks' gestation. The only ...known cure for this disease is delivery. Some obstetricians advocate early delivery to ensure that the development of serious maternal complications, such as eclampsia (fits) and kidney failure are prevented. Others prefer a more expectant approach, delaying delivery in an attempt to reduce the mortality and morbidity for the child that is associated with being born too early.
Objectives
To evaluate the comparative benefits and risks of a policy of early delivery by induction of labour or by caesarean section, after sufficient time has elapsed to administer corticosteroids, and allow them to take effect; with a policy of delaying delivery (expectant care) for women with severe pre‐eclampsia between 24 and 34 weeks' gestation.
Search methods
For this update, we searched Cochrane Pregnancy and Childbirth’s Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) on 27 November 2017, and reference lists of retrieved studies.
Selection criteria
Randomised trials comparing the two intervention strategies for women with early onset, severe pre‐eclampsia. Trials reported in an were eligible for inclusion, as were cluster‐trial designs. We excluded quasi‐randomised trials.
Data collection and analysis
Three review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. We assessed the quality of the evidence for specified outcomes using the GRADE approach.
Main results
We included six trials, with a total of 748 women in this review. All trials included women in whom there was no overriding indication for immediate delivery in the fetal or maternal interest. Half of the trials were at low risk of bias for methods of randomisation and allocation concealment; and four trials were at low risk for selective reporting. For most other domains, risk of bias was unclear. There were insufficient data for reliable conclusions about the comparative effects on most outcomes for the mother. Two studies reported on maternal deaths; neither study reported any deaths (two studies; 320 women; low‐quality evidence). It was uncertain whether interventionist care reduced eclampsia (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.06 to 15.58; two studies; 359 women) or pulmonary oedema (RR 0.45, 95% CI 0.07 to 3.00; two studies; 415 women), because the quality of the evidence for these outcomes was very low. Evidence from two studies suggested little or no clear difference between the interventionist and expectant care groups for HELLP (haemolysis, elevated liver enzymes, and low platelets) syndrome (RR 1.09, 95% CI 0.62 to 1.91; two studies; 359 women; low‐quality evidence). No study reported on stroke. With the addition of data from two studies for this update, there was now evidence to suggest that interventionist care probably made little or no difference to the incidence of caesarean section (average RR 1.01, 95% CI 0.91 to 1.12; six studies; 745 women; Heterogeneity: Tau² = 0.01; I² = 63%).
For the baby, there was insufficient evidence to draw reliable conclusions about the effects on perinatal deaths (RR 1.11, 95% CI 0.62 to 1.99; three studies; 343 women; low‐quality evidence). Babies whose mothers had been allocated to the interventionist group had more intraventricular haemorrhage (RR 1.94, 95% CI 1.15 to 3.29; two studies; 537 women; moderate‐quality evidence), more respiratory distress caused by hyaline membrane disease (RR 2.30, 95% CI 1.39 to 3.81; two studies; 133 women), required more ventilation (RR 1.50, 95% CI 1.11 to 2.02; two studies; 300 women), and were more likely to have a lower gestation at birth (mean difference (MD) ‐9.91 days, 95% CI ‐16.37 to ‐3.45 days; four studies; 425 women; Heterogeneity: Tau² = 31.74; I² = 76%). However, babies whose mothers had been allocated to the interventionist group were no more likely to be admitted to neonatal intensive care (average RR 1.19, 95% CI 0.89 to 1.60; three studies; 400 infants; Heterogeneity: Tau² = 0.05; I² = 84%). Babies born to mothers in the interventionist groups were more likely to have a longer stay in the neonatal intensive care unit (MD 7.38 days, 95% CI ‐0.45 to 15.20 days; three studies; 400 women; Heterogeneity: Tau² = 40.93, I² = 85%) and were less likely to be small‐for‐gestational age (RR 0.38, 95% CI 0.24 to 0.61; three studies; 400 women). There were no clear differences between the two strategies for any other outcomes.
Authors' conclusions
This review suggested that an expectant approach to the management of women with severe early onset pre‐eclampsia may be associated with decreased morbidity for the baby. However, this evidence was based on data from only six trials. Further large, high‐quality trials are needed to confirm or refute these findings, and establish if this approach is safe for the mother.
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