Birth outcomes following cesarean delivery on maternal request: a population-based cohort study

BACKGROUND:Data on the effect of cesarean delivery on maternal request (CDMR) on maternal and neonatal outcomes are inconsistent and often limited by inadequate case definitions and other methodological issues. Our objective was to evaluate the trends, determinants and outcomes of CDMR using an intent-to-treat approach.METHODS:We designed a population-based retrospective cohort study using data on low-risk pregnancies in Ontario, Canada (April 2012–March 2018). We assessed temporal trends and determinants of CDMR. We estimated the relative risks for component and composite outcomes used in the Adverse Outcome Index (AOI) related to planned CDMR compared with planned vaginal delivery using generalized estimating equation models. We compared the Weighted Adverse Outcome Score (WAOS) and the Severity Index (SI) across planned modes of delivery using analysis of variance.RESULTS:Of 422 210 women, 0.4% (n = 1827) had a planned CDMR and 99.6% (n = 420 383) had a planned vaginal delivery. The prevalence of CDMR remained stable over time at 3.9% of all cesarean deliveries. Factors associated with CDMR included late maternal age, higher education, conception via in vitro fertilization, anxiety, nulliparity, being White, delivery at a hospital providing higher levels of maternal care and obstetrician-based antenatal care. Women who planned CDMR had a lower risk of adverse outcomes than women who planned vaginal delivery (adjusted relative risk 0.42, 95% confidence interval [CI] 0.33 to 0.53). The WAOS was lower for planned CDMR than planned vaginal delivery (mean difference −1.28, 95% CI −2.02 to −0.55). The SI was not statistically different between groups (mean difference 3.6, 95% CI −7.4 to 14.5).Interpretation:Rates of CDMR have not increased in Ontario. Planned CDMR is associated with a decreased risk of short-term adverse outcomes compared with planned vaginal delivery. Investigation into the long-term implications of CDMR is warranted.

Cesarean delivery is the most common inpatient surgical procedure in North America,^1,2 where rates often exceed World Health Organization recommendations (10%–15% of deliveries).³ Given the financial and resource implications of cesarean deliveries on health care systems, the contribution of cesarean deliveries on maternal request (CDMR) to rising cesarean section rates is of ongoing interest. Women may prefer CDMR for many reasons, including scheduling convenience, anxiety regarding labour pain, perceptions that the quality of obstetrical care is better for women who have cesarean deliveries, and concerns about possible urinary incontinence and sexual dysfunction after vaginal delivery.^4–7 Challenges in characterizing the epidemiology of CDMR include the lack of internationally accepted case definitions and inconsistencies in documentation that hinder meaningful comparisons across jurisdictions.^8–11 In Canada, the prevalence of CDMR has been estimated at 2% of cesarean deliveries,¹² but robust contemporary data are lacking.The benefits of vaginal delivery are well known and include a lower risk of transient tachypnea of the newborn, newborn exposure to the vaginal microbiome, shorter maternal hospital stays and lower risk of complications associated with abdominal surgeries. The findings of 1 Canadian study suggest that midpelvic operative vaginal delivery is associated with a greater risk of severe birth and obstetric trauma than cesarean delivery.¹³ Evidence on the risks and benefits of CDMR is sparse, and existing data are inconsistent.^14–19 Analyses are frequently limited by inadequate case definitions and unaddressed confounding from baseline maternal and neonatal factors.^4,11 Professional organizations in the United States, Canada and Europe do not recommend CDMR over vaginal delivery.^11,20–22 Patient counselling is suggested to inform patients of pain management options, and of potential benefits and harms related to cesarean deliveries. However, obstetrical care providers often accede to patient preferences, given the ethical imperative of patient autonomy. ^23–27 Contemporary, high-quality observational studies leveraging robust population-based data are required. Our objective was to evaluate the trends, determinants and outcomes of CDMR compared with planned vaginal delivery using an intent-to-treat approach.     

Archaeosomes made of Halorubrum tebenquichense total polar lipids: a new source of adjuvancy

Background  

Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new sources of adjuvancy, here we report the presence of two new Halorubrum tebenquichense strains isolated from grey crystals (GC) and black mood (BM) strata from a littoral Argentinean Patagonia salt flat. Cytotoxicity, intracellular transit and immune response induced by two subcutaneous (sc) administrations (days 0 and 21) with BSA entrapped in ARC made of TPL either form BM (ARC-BM) and from GC (ARC-GC) at 2% w/w (BSA/lipids), to C3H/HeN mice (25 μg BSA, 1.3 mg of archaeal lipids per mouse) and boosted on day 180 with 25 μg of bare BSA, were determined.     

Migration patterns counteract seasonal isolation of <Emphasis Type="Italic">Squalius torgalensis</Emphasis>, a critically endangered freshwater fish inhabiting a typical Circum-Mediterranean small drainage

Freshwater species with small distribution ranges are vulnerable to extinction, especially when they exhibit small effective population sizes. Squalius torgalensis, Cyprinidae, is an endemic critically endangered fish species from southwestern Portugal, confined to the intermittent streams of the Mira drainage. Assessment of genetic diversity and population structure levels was conducted through the analysis of both mitochondrial (cytochrome b) and nine nuclear microsatellite markers. Remarkable low levels of genetic diversity for both markers were observed (He < 0.38, π < 0.001). These results may be related with the restricted distribution range and dispersion patterns of the species together with demographic fluctuations associated with the intermittent features of the river system. Population structure analyses suggest the existence of two incipient divergent populations; one comprising the tributaries located upstream and the other comprising downstream tributaries of the Mira River. Data also supports the occurrence of high gene flow mainly from downstream to upstream, failing to reflect isolation of populations due to seasonal drought. Obtained results should be incorporated in future management plans for the species. These should be centred around the current connection between populations and on the maintenance of suitable habitat patches, not only for reproduction, but also for summer refuges.