Intrapartum epidural analgesia and breastfeeding: a prospective cohort study

BACKGROUND Anecdotal reports suggest that the addition of fentanyl (an opioid) to epidural analgesia for women during childbirth results in difficulty establishing breastfeeding. The aim of this paper is to determine any association between epidural analgesia and 1) breastfeeding in the first week postpartum and 2) breastfeeding cessation during the first 24 weeks postpartum. METHODS A prospective cohort study of 1280 women aged > or = 16 years, who gave birth to a single live infant in the Australian Capital Territory in 1997 was conducted. Women completed questionnaires at weeks 1, 8, 16 and 24 postpartum. Breastfeeding information was collected in each of the four surveys and women were categorised as either fully breastfeeding, partially breastfeeding or not breastfeeding at all. Women who had stopped breastfeeding since the previous survey were asked when they stopped. RESULTS In the first week postpartum, 93% of women were either fully or partially breastfeeding their baby and 60% were continuing to breastfeed at 24 weeks. Intrapartum analgesia and type of birth were associated with partial breastfeeding and breastfeeding difficulties in the first postpartum week (p < 0.0001). Analgesia, maternal age and education were associated with breastfeeding cessation in the first 24 weeks (p < 0.0001), with women who had epidurals being more likely to stop breastfeeding than women who used non-pharmacological methods of pain relief (adjusted hazard ratio 2.02, 95% CI 1.53, 2.67). CONCLUSION Women in this cohort who had epidurals were less likely to fully breastfeed their infant in the few days after birth and more likely to stop breastfeeding in the first 24 weeks. Although this relationship may not be causal, it is important that women at higher risk of breastfeeding cessation are provided with adequate breastfeeding assistance and support.Christine Roberts is supported by a National Health and Medical Research Council (NHMRC) of Australia Public Health Practitioner Fellowship and Siranda Torvaldsen is supported by a NHMRC Australian Research Training Fellowship. The cohort study was supported by a project grant from The Canberra Hospital Private Practice Fund. Additional funding was provided by The Canberra Hospital Auxiliary, the Nurses' Board of the Australian Capital Territory, and the Australian Capital Territory Department of Health & Community Care

Faraday rotation maps of disk galaxies

Faraday rotation is one of the most widely used observables to infer the strength and configuration of the magnetic field in the ionised gas of the Milky Way and nearby spiral galaxies. Here we compute synthetic Faraday rotation maps at $z=0$ for a set of disk galaxies from the Auriga high-resolution cosmological simulations, for different observer positions within and outside the galaxy. We find that the strength of the Faraday rotation of our simulated galaxies for a hypothetic observer at the solar circle is broadly consistent with the Faraday rotation seen for the Milky Way. The same holds for an observer outside the galaxy and the observed signal of the nearby spiral galaxy M51. However, we also find that the structure and angular power spectra of the synthetic all-sky Faraday rotation maps vary strongly with azimuthal position along the solar circle. We argue that this variation is a result of the structure of the magnetic field of the galaxy that is dominated by an azimuthal magnetic field ordered scales of several kpc, but has radial and vertical magnetic field components that are only ordered on scales of 1-2 kpc. Because the magnetic field strength decreases exponentially with height above the disk, the Faraday rotation for an observer at the solar circle is dominated by the local environment. This represents a severe obstacle for attempts to reconstruct the global magnetic field of the Milky Way from Faraday rotation maps alone without including additional observables.Comment: 10 pages, 10 figures, accepted by MNRA

The role of cosmic ray pressure in accelerating galactic outflows

We study the formation of galactic outflows from supernova explosions (SNe) with the moving-mesh code AREPO in a stratified column of gas with a surface density similar to the Milky Way disk at the solar circle. We compare different simulation models for SNe placement and energy feedback, including cosmic rays (CR), and find that models that place SNe in dense gas and account for CR diffusion are able to drive outflows with similar mass loading as obtained from a random placement of SNe with no CRs. Despite this similarity, CR-driven outflows differ in several other key properties including their overall clumpiness and velocity. Moreover, the forces driving these outflows originate in different sources of pressure, with the CR diffusion model relying on non-thermal pressure gradients to create an outflow driven by internal pressure and the random-placement model depending on kinetic pressure gradients to propel a ballistic outflow. CRs therefore appear to be non-negligible physics in the formation of outflows from the interstellar medium.Comment: 8 pages, 4 figures, accepted for publication in ApJL; movie of simulated gas densities can be found here: http://www.h-its.org/tap-images/galactic-outflows

Pregnancy outcomes for women with rare autoimmune diseases

Objective: To examine pregnancy outcomes and pregnancy-related health service utilisation among women with rare autoimmune diseases. Methods: This population-based cohort study of an Australian obstetric population (New South Wales 2001-2011) used birth records linked to hospital records for identification of rare autoimmune diseases including systemic vasculitis, vasculitis limited to skin, systemic sclerosis, dermatopolymyositis and other systemic involvement of connective tissue. We excluded births to women with systemic lupus erythematosus or rheumatoid arthritis and births >6 months before the first documented diagnosis of the rare autoimmune disease. Modified Poisson regression was used to compare study outcomes between women with autoimmune diseases and the general obstetric population. Results: There were 991,701 births including 409 (0.04%) births to 293 women with rare autoimmune diseases. Of the 409 pregnancies, 202 (49%) delivered by cesarean delivery and 72 (18%) were preterm; these rates were significantly higher than those in the general obstetric population (28% and 7% respectively). Compared to the general population, women with autoimmune diseases had higher rates of hypertensive disorders, antepartum hemorrhage and severe maternal morbidity, and required longer hospitalization at delivery and more hospital admissions and tertiary obstetric care. Compared to other infants, those whose mothers had a rare autoimmune disease were at increased risk of admission to neonatal intensive care unit, severe neonatal morbidity and perinatal death. Conclusions: Women with rare autoimmune diseases were at increased risk of having both maternal complications and adverse neonatal outcomes; their pregnancies should be closely monitored.NHMRC; Rolf Edgar Lake Postdoctoral Fellowship, University of Sydne