Effects of Pre-Term Birth on the Cardio-Respiratory Responses to Hypoxic Exercise in Children

Pre-term birth is associated with numerous cardio-respiratory sequelae in children. Whether these impairments impact the responses to exercise in normoxia or hypoxia remains to be established. Fourteen prematurely-born (PREM) (Mean ± SD; gestational age 29 ± 2 weeks; age 9.5 ± 0.3 years), and 15 full-term children (CONT) (gestational age 39 ± 1 weeks; age 9.7 ± 0.9 years), underwent incremental exercise tests to exhaustion in normoxia (FiO2 = 20.9%) and normobaric hypoxia (FiO2 = 13.2%) on a cycle ergometer. Cardio-respiratory variables were measured throughout. Peak power output was higher in normoxia than hypoxia (103 ± 17 vs. 77 ± 18 W; p < 0.001), with no difference between CONT and PREM (94 ± 23 vs. 86 ± 19 W; p = 0.154). V̇O2peak was higher in normoxia than hypoxia in CONT (50.8 ± 7.2 vs. 43.8 ± 9.9 mL·kg−1·min−1; p < 0.001) but not in PREM (48.1 ± 7.5 vs. 45.0 ± 6.8 mL·kg−1·min−1; p = 0.137; interaction p = 0.044). Higher peak heart rate (187 ± 11 vs. 180 ± 10 bpm; p = 0.005) and lower stroke volume (72 ± 13 vs. 77 ± 14 mL; p = 0.004) were observed in normoxia versus hypoxia in CONT, with no such differences in PREM (p = 0.218 and > 0.999, respectively). In conclusion, premature birth does not appear to exacerbate the negative effect of hypoxia on exercise capacity in children. Further research is warranted to identify whether prematurity elicits a protective effect, and to clarify the potential underlying mechanisms.

Ureaplasma and Prevotella Colonization with Lactobacillus Abundance During Pregnancy Facilitates Term Birth

Ureaplasma and Prevotella infections are well-known bacteria associated with preterm birth. However, with the development of metagenome sequencing techniques, it has been found that not all Ureaplasma and Prevotella colonizations cause preterm birth. The purpose of this study was to determine the association between Ureaplasma and Prevotella colonization with the induction of preterm birth even in the presence of Lactobacillus. In this matched case-control study, a total of 203 pregnant Korean women were selected and their cervicovaginal fluid samples were collected during mid-pregnancy. The microbiome profiles of the cervicovaginal fluid were analyzed using 16S rRNA gene amplification. Sequencing data were processed using QIIME1.9.1. Statistical analyses were performed using R software, and microbiome analysis was performed using the MicrobiomeAnalyst and Calypso software. A positive correlation between Ureaplasma and other genera was highly related to preterm birth, but interestingly, there was a negative correlation with Lactobacillus and term birth, with the same pattern observed with Prevotella. Ureaplasma and Prevotella colonization with Lactobacillus abundance during pregnancy facilitates term birth, although Ureaplasma and Prevotella are associated with preterm birth. Balanced colonization between Lactobacillus and Ureaplasma and Prevotella is important to prevent preterm birth.

Preterm birth is strongly affected by the glucocorticoid dose during pregnancy in women complicated by systemic lupus erythematosus

Background This study aimed to investigate the effect of glucocorticoid doses on adverse pregnancy outcomes (APOs) in women complicated by systemic lupus erythematosus (SLE). Methods We investigated 74 pregnancies complicated by SLE or SLE-dominant mixed connective tissue disease. The pregnancies were managed from conception to delivery in our institution. We retrospectively evaluated whether the mean glucocorticoid dose during pregnancy is associated with APOs, including preterm birth (PB), low birth weight (LBW), and light-for-date (LFD). We also calculated the cut-off dose of glucocorticoid that affected APOs. Results All APOs occurred in 35 (50.7%) patients, with 14 cases of PB, 23 cases of LBW, and 10 cases of LFD. Patients with all APOs or PB had a higher dose of glucocorticoid during pregnancy than patients without all APOs or with full-term birth (P = 0.03, P < 0.01, respectively). Logistic regression analysis for all APOs and PB showed that the cut-off values of the mean glucocorticoid dose were 6.5 and 10.0 mg/day, respectively. Patients who delivered LBW or LFD newborns showed no significant difference in the glucocorticoid dose used during pregnancy than patients without LBW or LFD newborns. Patients who delivered LBW newborns were more likely to have used glucocorticoids during pregnancy (P < 0.01). Conclusions In pregnancies complicated by SLE, a relatively lower dose of glucocorticoid than previously reported is significantly related to APOs, especially PB. Therefore, the disease activity of patients with SLE should be managed with the appropriate lower dose of glucocorticoid during pregnancy.

Low length/weight growth trajectories of early-term infants during the first year: evidence from a longitudinal study in China

ObjectiveTo identify common length, weight and body mass index (BMI) growth trajectories of term infants during infancy, and to determine their association with early-term infants.DesignProspective longitudinal study.SettingWuhan, China.PatientsA total of 4308 term infants (born at 37–41 weeks of gestation) were included. All term infants were single live birth with no defects and birth weight ≥2500 g, and their mothers were permanent residents of Wuhan for more than 2 years. After excluding 887 infants, a total of 3421 term infants (1028 early-term infants born at 37–38 weeks of gestation and 2393 full-term infants born at 39–41 weeks of gestation) entered the statistical analysis stage.Main outcome measuresPatterns of length, weight and BMI growth trajectories by using group-based trajectory modelling.ResultsThree distinct physical growth trajectories were identified as follows: length: low stable (1056, 30.9%), moderate stable (1887, 55.2%) and high increasing (477, 13.9%); weight: low stable (1031, 30.1%), moderate stable (1884, 55.1%) and high increasing (505, 14.8%); BMI: low stable (689, 20.1%), moderate stable (2167, 63.4%) and high increasing (564, 16.5%). Compared with the full-term infants, early-term infants were more likely to remain at low-stable trajectory in length (OR: 1.40; 95% CI: 1.19 to 1.66) and weight (OR:1.29; 95% CI: 1.09 to 1.53). These associations were still statistically significant after adjusting potential confounders and were more evident among girls in the stratified analysis. There was no statistical association between BMI trajectory patterns and gestational age categories.ConclusionOur results suggested the heterogeneity of term infants existed in length, weight and BMI growth trajectories of early childhood. Compared with full-term birth, early-term birth was related to low length and weight trajectories rather than BMI trajectory. Further research is needed to evaluate the duration of these low trajectories and their possible long-term health effects.

Early-term birth and its association with universal two-child policy: a national cross-sectional study in China

ObjectiveTo describe the epidemiology of early-term birth (ETB) at the national level in China, and explore the association and mediating factors between ETB and policy between universal two-child policy and ETB, so as to explain the potential reason for such a relationship and provide evidence for future ETB interventions in the era of the new birth control policy.DesignCross-sectional study.ParticipantsThe cross-sectional study used data from China Labour and Delivery Survey between 2015 and 2016. A total of 75 132 survey data collected from 89 hospitals in 25 provinces were included in the analysis. We further explored the association between the universal two-child policy and ETB.ResultsThe weighted incidence of ETB was 30.1 per 100 all births (95% CI 30.06% to 30.14%) or 29.88 per 100 live births (95% CI 29.97% to 30.05%) between 2015 and 2016 in China. There was an association between the universal two-child policy and ETB (relative risk, RR 1.19, 95% CI 1.15 to 1.23), which was not mediated by maternal age (RR 1.17, 95% CI 1.13 to 1.22), previous uterine scars (RR 1.18, 95% CI 1.14 to 1.22), parity (RR 1.19, 95% CI 1.15 to 1.24) and other measured conditions (each p<0.05). Stratified analysis showed that the association between universal two-child policy and ETB were the strongest in multiparous young women or women without previous uterine scars (each p<0.05), and disappeared in all women of advanced maternal age (each p>0.05).ConclusionThe incidence of ETB was high in China when compared with most of reported countries, and there might be a link between two-child policy and ETB. Obstetric practice such as selective induced labour and caesarean section should be revised with ETB risks in mind, when ETB is more likely to happen under the universal two-child policy. Preventing ETB should not be neglected in multiparous young women or those without previous uterine scars under the new policy.

Pregnancy as a Risk Factor of Severe COVID-19

Since first being identified in December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as an etiological agent behind Coronavirus disease 19 (COVID-19), has caused three waves of a global pandemic, with a fourth in progress. Despite its high percentage of asymptomatic and low-symptomatic courses of illness, the SARS-CoV-2 pandemic has claimed a higher death toll than the SARS-CoV and MERS-CoV epidemics because of its high infectivity when compared to the other coronaviruses. High COVID-19 mortality is associated with age and other coexisting morbidities, as well as healthcare quality. According to several studies, pregnant women are at a higher risk of severe COVID-19 infection and adverse pregnancy outcomes (caesarean delivery, pre-term birth, low birth weight, preeclampsia, ICU admission, and need for mechanical ventilation). In our review of recent literature, we focused on the effects of COVID-19 in pregnant women, emphasizing the subcellular pathophysiology of SARS-CoV-2. In this paper, we concentrate on the pathophysiology of sub-cellular changes in COVID-19 and endeavor to highlight the aspects that manifest in physiological pregnancy and potentially create a higher risk of SARS-CoV-2 infection and acute COVID-19 symptoms. Understanding how pregnancy-associated changes can cause a synergistic effect with COVID-19 may point us in the right direction for future prophylaxis and treatment for women undergoing COVID-19 during pregnancy.

WNT3 hypomethylation counteracts low activity of the Wnt signaling pathway in the placenta of preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy. Many studies have shown that epigenetic mechanisms may play a role in preeclampsia. Moreover, our previous study indicated that the differentially methylated genes in preeclampsia were enriched in the Wnt/β-catenin signaling pathway. This study aimed to identify differentially methylated Wnt/β-catenin signaling pathway genes in the preeclamptic placenta and to study the roles of these genes in trophoblast cells in vitro. Using an Illumina Infinium HumanMethylation 850 K BeadChip, we found that the Wnt signaling pathway was globally hypermethylated in the preeclamptic group compared with the term birth group, but hypomethylated in the preeclamptic group compared with the preterm birth group. Among all Wnt/β-catenin signaling pathway factors, WNT3 was the most significantly differentially expressed gene and was hypomethylated in the preeclamptic group compared to the nonhypertensive groups, namely, the preterm birth group and term birth group. This result was confirmed by pyrosequencing. Through quantitative real-time PCR and western blot analysis, the WNT3 gene was found to be highly expressed in preeclamptic placental tissues, in contrast to other WNT factors, which were previously reported to be expressed at low levels in placental tissues. Additionally, in the HTR8/SVneo cell line, knockdown of WNT3 suppressed the Wnt/β-catenin signaling pathway, consistent with the findings for other WNT factors. These results prompted us to speculate that the WNT3 gene counteracts the low activation state of the Wnt signaling pathway in the preeclamptic placenta through methylation modification.

Pre-Cerclage Cervical Length—A Reliable Predictor of Long-Term Pregnancy Sustenance After Therapeutic Cervical Cerclage: A Retrospective Study

Background: The indication of therapeutic cerclage is still controversial. The purpose of this study was to assess pregnancy outcomes after cervical cerclage in women with shortened cervical length (CL) during pregnancy and/or with a medical history of cervical insufficiency. Methods: We included pregnant women who underwent cerclage in four perinatal medical centers between January 2009 and December 2010. We compared the outcomes of cerclage in terms of non-term and term births, as well as successful and unsuccessful cerclages. Cervical cerclage was defined as successful if pregnancy was continued for more than 13 weeks post-cerclage. Therapeutic and prophylactic cerclages were performed in pregnant women with pre-cerclage CL < 25 mm and ≥ 25 mm, respectively.Results: We screened 114 pregnant women, of whom 91 were included; 15 and 8 women were excluded for unknown pregnancy outcomes and multiple gestation, respectively. The rate of therapeutic cerclage was significantly higher in the non-term birth (68% vs. 38%, p <0.01; non-term group vs. term birth group), unsuccessful cerclage (79% vs. 43%, p =0.01; unsuccessful cerclage vs. successful cerclage) groups. Inflammatory marker levels (white blood cell count and C-reactive protein) were normal in both group sets, albeit no significantly different between-group differences. Receiver-operating characteristic curve analysis revealed that 87% of patients with pre-cerclage CL ≥ 17 mm sustained their pregnancies for more than 13 weeks post-cerclage. However, 64% of patients with pre-cerclage CL < 17 mm did not sustain their pregnancies for more than 13 weeks post-cerclage.Conclusions: Therapeutic cerclage should be performed in patients with cervical insufficiency having CL ≥ 17 mm, for long-term pregnancy sustenance.