Does Dietitian Involvement During Pregnancy Improve Birth Outcomes? A Systematic Review.

Maternal diet during pregnancy can have a significant impact on maternal and offspring health. As nutrition counselling is an important component of prenatal care, registered dietitians (RDs) are uniquely trained professionals who can provide personalized nutrition counselling customized to an individual's sociocultural needs. The objective of this systematic review was to determine if RD involvement during pregnancy is associated with a lower prevalence of adverse birth outcomes in the United States and Canada. The review was conducted through a search of four databases: PubMed, CINAHL, Embase, and Web of Science. A total of 14 studies were identified. Women had a lower prevalence of low birth weight and preterm infants when RDs were involved during prenatal care. While RD involvement during pregnancy was not associated with macrosomia, more research is needed to assess its relationship with small for gestational age, large for gestational age, and infant mortality. Future research should also investigate the specific dietary advice provided by RDs and the extent and timing of their involvement throughout pregnancy to better understand the mechanisms surrounding nutrition counselling, in utero development, and health outcomes.

Maternal Eating Disorders and Adverse Birth Outcomes: A Systematic Review and Meta-Analysis.

Previous systematic reviews have reported on the relationship between eating disorders (EDs) and birth outcomes, but there are no existing meta-analyses on this topic. This systematic review and meta-analysis examines the association between lifetime maternal EDs, including anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorder (BED) with low birth weight (LBW), preterm birth (PTB), small for gestational age (SGA), large for gestational age (LGA), and miscarriage. Four databases were systematically searched for quantitative literature on maternal EDs that preceded birth outcomes. Eighteen studies met the inclusion criteria and were included in the review. The meta-analyses included 6 studies on miscarriage, 11 on PTB, 4 on LBW, 9 on SGA, and 4 on LGA. The Mantel-Haenszel random effects model was used to test the associations between EDs and birth outcomes. The results showed significant positive associations between AN and LBW (OR 1.74, 95% confidence interval (CI) 1.49, 2.03), AN and SGA (OR 1.39, 95% CI 1.17, 1.65), BN and PTB (OR 1.19, 95% CI 1.04, 1.36), and BED and LGA (OR 1.43 95% CI 1.18, 1.72). EDs were not significantly correlated with miscarriage. These findings reveal the importance of screening for and treating EDs in pregnant women.

Correlates of self-harm in university students: A cross-sectional study.

Objective: To determine the prevalence of university students who have ever engaged in self-harm and to examine its correlates. Frequency of thinking about self-harm was explored as a secondary outcome. Participants: Students at Western University in London, Ontario, Canada. Methods: This cross-sectional study was completed via an online questionnaire. Logistic regressions assessed the influence of sociodemographic and behavioral factors associated with lifetime self-harm and thoughts about self-harm. Results: The sample consisted of 2626 university students. Almost 25% engaged in self-harm in their lifetime and close to 33% have thought about harming themselves. A non-straight sexual orientation, marijuana use, prescription drugs not prescribed, and mental health problems increased the risk of both outcomes. Females were over two times more likely to engage in self-harm than males. Conclusion: This study provides evidence that is needed for developing effective interventions to reduce the risk of self-harm by targeting university students who are most at-risk.

Identifiable Dietary Patterns of Pregnant Women: A Canadian Sample.

Purpose: To estimate the percentage of a sample of pregnant women in Canada following a vegetarian, vegan, low-carbohydrate, gluten-free, Mediterranean, or well-balanced diet, before and during pregnancy and to explore if pregnant women received and were satisfied with nutrition information received from health care providers (HCPs).Methods: Participants were conveniently sampled through Facebook and Twitter. An online survey collected data on sociodemographic characteristics, maternal diet, and whether women received and were satisfied with nutrition information from their HCPs. The McNemar test assessed changes in the proportion of diets followed before and during pregnancy.Results: Of 226 women, most followed a well-balanced diet before (76.9%) and during (72.9%) pregnancy (p = 0.26). Vegetarian, gluten-free, vegan, and low-carbohydrate diets were the least followed diets before and during pregnancy (vegetarian: 7.6% vs 5.3%; gluten-free: 4.9% vs 4.0%; vegan: 2.7% vs 2.2%; low-carbohydrate:4.0% vs 0.4%). Overall, the number of women following restrictive diets before pregnancy was significantly reduced throughout pregnancy (19.1% vs 12.0%, p < 0.001). Only 52.0% of women received nutrition information from their primary HCP, and 35.6% were satisfied with the nutrition information received.Conclusions: Most women followed a well-balanced diet before and during pregnancy and approximately one-third were satisfied with the information received from HCPs.

Correlates of Lifetime and Past Month Vape Use in a Sample of Canadian University Students.

INTRODUCTION: This study examines correlates of lifetime (ie, ever vaped) and past month vape use among students aged 17 to 19 years, 20 to 25 years, and 26+ years from Western University in London, Ontario. The secondary objective is to assess lifetime and past month vape use among students not of legal age to purchase vaping products in Ontario (ie, those 17 to 18 years only). METHODS: Using Qualtrics, a cross-sectional survey was sent via email to all students at Western University (N = 38 442), assessing their current and past risk-taking behaviors, mental health, sociodemographic characteristics, as well as questions pertaining to their family structure and socioeconomic background during childhood. Students were asked if they had ever vaped in their lifetime and about past month vape use. Logistic regression models were used to assess correlates of lifetime and past month vape use. RESULTS: The sample consisted of 2626 university students. Compared to those ages 26+ years, teenage university students were 10 times more likely to have vaped in the past month and males were twice as likely as females to have vaped. Alcohol use doubled the odds of vaping in the past month, whereas cigarette, cannabis, or cocaine use approximately tripled the odds. Students who reported many sexual partners were far more likely to have vaped in the past month. CONCLUSION: Vape use is more common among teenage university students, males, those who drink alcohol, smoke, use cannabis or cocaine, and who report many sexual partners.

A Review of Statistical Reporting in Dietetics Research (2010-2019): How is a Canadian Journal Doing?

Despite the widespread use of statistical techniques in quantitative research, methodological flaws and inadequate statistical reporting persist. The objective of this study is to evaluate the quality of statistical reporting and procedures in all original, quantitative articles published in the Canadian Journal of Dietetic Practice and Research (CJDPR) from 2010 to 2019 using a checklist created by our research team. In total, 107 articles were independently evaluated by 2 raters. The hypothesis or objective(s) was clearly stated in 97.2% of the studies. Over half (51.4%) of the articles reported the study design and 57.9% adequately described the statistical techniques used. Only 21.2% of the studies that required a prestudy sample size calculation reported one. Of the 281 statistical tests conducted, 88.3% of them were correct. P values >0.05-0.10 were reported as "statistically significant" and/or a "trend" in 11.4% of studies. While this evaluation reveals both strengths and areas for improvement in the quality of statistical reporting in CJDPR, we encourage dietitians to pursue additional statistical training and/or seek the assistance of a statistician. Future research should consider validating this new checklist and using it to evaluate the statistical quality of studies published in other nutrition journals and disciplines.

Prevalence of Low Birth Weight, Premature Birth, and Stillbirth Among Pregnant Adolescents in Canada: A Systematic Review and Meta-analysis.

Although most studies show that adolescent pregnant women are at a higher risk for adverse birth outcomes, there has been limited research examining this relationship in Canada. This systematic review and meta-analysis investigated the prevalence of low birthweight (LBW), preterm birth (PTB), and stillbirth in Canadian adolescent women compared to adult women. Studies were included if they were primary research and included a sample of adolescent mothers (≤19 years) and adult mothers (≥20 years) who gave birth to singleton infants in Canada. Birth outcomes must have been measured consistently in at least 3 studies for inclusion. Comprehensive electronic literature searches were conducted from database inception until August 2020 in 5 databases. Random effects meta-analysis models were used to estimate pooled odds ratios (pOR) for LBW, PTB, and stillbirth between adolescent and adult pregnant women. Outcomes reported included PTB (8 studies), LBW (6 studies), and stillbirth (3 studies). Compared to adult mothers, adolescent mothers had a 56% increase in the prevalence of LBW (pOR 1.56, 95% confidence interval [CI] 1.24, 1.97), a 23% increase in PTB (pOR 1.23, 95% CI 1.06, 1.42), a 20% increase in stillbirth (pOR 1.20, 95% CI 1.05, 1.37). Heterogeneity, as assessed by I2, was high for LBW and PTB and was low for stillbirth. A subgroup analysis did not remove the high heterogeneity, and some studies did not adjust for confounding variables and were missing information on sociodemographic and behavioral factors. Future research is needed to investigate the mechanisms surrounding these differences by maternal age.

Antenatal depression and offspring health outcomes.

BACKGROUND: Depression is the most common mental disorder during pregnancy, with prevalence rates between 4% and 20%. The objective of this review was to synthesize the literature on the association between antenatal depression and offspring birth outcomes, as well as developmental, behavioral, and psychiatric outcomes. METHODS: A search of PubMed, Cochrane, and Medline databases was conducted for articles published until December 2017. Articles focusing on the effects of antenatal depression on the offspring were selected to be reviewed. Reference lists of all studies were examined for any missed articles. A total of 32 articles were included in this review. RESULTS: Antenatal depression is associated with preterm birth, excessive infant crying, and offspring mental health problems. Untreated antenatal depression is strongly associated with adverse effects on the infant nervous system. CONCLUSION: Antenatal depression increases the likelihood of poor offspring health outcomes. Research should investigate whether medication use confounds this relationship.

Risk Factors and Birth Outcomes Associated with Teenage Pregnancy: A Canadian Sample.

STUDY OBJECTIVE: To examine the extent to which socioeconomic status, mental health, and substance use are associated with teenage pregnancies in Southwestern Ontario (SWO), and whether these pregnancies are at an elevated risk for adverse birth outcomes, after controlling for medical, behavioral, and socioeconomic status factors. DESIGN: Retrospective cohort study using perinatal and neonatal databases. SETTING: Tertiary care hospital in SWO. PARTICIPANTS: Women residing in SWO who gave birth to singleton infants without congenital anomalies between 2009 and 2014. Teenage pregnancies (19 years of age or younger) were compared with pregnancies of women 20-34 years and 35 years or older. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Low birth weight (LBW), very LBW, term LBW, preterm birth, very preterm birth, low and very low Apgar score, and fetal macrosomia. RESULTS: Of 25,263 pregnant women, 1080 (4.3%) were 19 years of age or younger. Approximately 18% of teenage mothers lived in socioeconomically disadvantaged neighborhoods, compared with 11% of mothers aged 20-34 and 9% of women 35 years of age or older (P < .001). Teenage mothers had higher rates of depression during pregnancy (9.8%) than mothers 20-34 years (5.8%) and those 35 years of age or older (6.8%; P < .001). Young mothers self-reported higher tobacco, marijuana, and alcohol use during pregnancy than adult mothers (P < .001). Teenage pregnancy increased the risk of a low Apgar score (adjusted odds ratio, 1.56; 95% confidence interval, 1.21-2.02), but was not associated with other birth outcomes after adjusting for covariates. CONCLUSION: Teenage pregnancy is associated with a higher risk of socioeconomic disadvantage, mental health problems, and substance use during pregnancy, but is largely unrelated to adverse birth outcomes in SWO.

The contribution of muscarinic-receptor-mediated responses to epineurial vascular diameter at the sciatic nerve.

This study used an anaesthetized rat model to directly observe changes in diameter of the vessels supplying the sciatic nerve in response to acetylcholine (10-4 M), a muscarinic receptor agonist, and atropine (10-5 M), a muscarinic receptor antagonist. Topical application of acetylcholine resulted in increases in vessel diameter (baseline: 22.0 ± 2.5 µm, acetylcholine: 28.8 ± 3.3 µm), while topical application of atropine resulted in a decrease in diameter (baseline: 26.6 ± 3.2 µm, atropine: 15.5 ± 3.6 µm) of the epineurial vessels. Mean arterial pressure was not affected by either acetylcholine (baseline: 103.8 ± 1.8 mm Hg, acetylcholine: 102.8 ± 3.2 mm Hg) or atropine (baseline: 104.0 ± 1.9 mm Hg, atropine: 105.2 ± 2.2 mm Hg). These data suggest that muscarinic-receptor-mediated responses can affect the diameter of the epineurial vessels at the sciatic nerve. In addition, muscarinic-receptor-mediated responses appear to contribute to baseline diameter of epineurial vessels at the sciatic nerve.

Use of an Experiential Learning Assignment to Prepare Future Health Professionals to Utilize Social Media for Nutrition Communications.

Social media has become a popular platform for reputable health organizations to disseminate health information to the public. However, future health professionals may receive little training in social media communication. To train future dietetic professionals, we incorporated a social media assignment into a Communications course curriculum to facilitate effective use of social media for the profession. For the assignment, students were instructed to make 2 posts on Facebook. The posts were due 3 weeks apart so that students received feedback on their first post before making their second post. To demonstrate the type of social media communication commonly used by reputable health organizations, the first post raised awareness or provided nutrition education. The second post used Facebook's "comment" feature, to respond to another student's first post, demonstrating the use of social media for community engagement. Both posts included a hyperlink that the user could click to get more information. Students were evaluated on the hook, main points, professionalism, credibility, and effectiveness of inviting the reader to the hyperlinked website and its ease of navigation. Dietetics educators should be encouraged to incorporate social media education into their curriculums for the benefit of future dietitians and their clients.

Glucose-stimulated insulin secretion causes an insulin-dependent nitric oxide-mediated vasodilation in the blood supply of the rat sciatic nerve.

This study tested the hypothesis that acute hyperglycemia reduces sciatic nerve blood flow in Sprague-Dawley rats. Anesthetized rats underwent cannulation of their right jugular vein (for anesthetic/nutrient/drug infusion) and right carotid artery (for continuous blood pressure measurement via pressure transducer). The left sciatic nerve was exposed and nerve blood velocity (NBV) was assessed from an arterial segment lying superficially along the sciatic nerve (Doppler ultrasound, 40 MHz). NBV and mean arterial pressure (MAP) values were collected, and an index of nerve vascular conductance (NVC) was established (NBV/MAP) at baseline and at 5, 10, 20, and 30 min (and 80 min for insulin) following 1) low glucose infusion, 1 g/kg (50% solution); 2) high glucose infusion, 3 g/kg; 3) high glucose infusion in the absence of a functioning pancreas; 4) euglycemic hyperinsulinemic clamp-insulin infusion (10 mU·kg⁻¹·min⁻¹; 0.4 IU/ml); 5) high glucose infusion + NG-nitro-L-arginine methyl ester (L-NAME) infusion (30 mg/kg); and 6) L-NAME alone followed 20 min later by high glucose infusion. High glucose infusion increased NVC by ~120% relative to baseline (P < 0.001), and this dilation was attenuated in rats without a functioning pancreas (i.e., without insulin secretion) (P = 0.004) and following L-NAME infusion (P = 0.011). Therefore, the vasodilation in rat sciatic nerve during glucose infusion was dependent upon the insulin response and acted through a nitric oxide synthase pathway.

Y1R control of sciatic nerve blood flow in the Wistar Kyoto rat.

We hypothesized that neuropeptide Y (NPY) exerts vasoconstrictor properties in sciatic nerve blood supply by a Y1 receptor (Y1R) mechanism. Using Doppler ultrasound (40MHz), we measured blood flow velocity through a sciatic nerve supply artery during infusions of NPY and/or Y1R blockade with BIBP3226 in Wistar Kyoto rats before, and following, ganglionic blockade with Hexamethonium (Hex). Following Hex infusion, mean arterial pressure (baseline: 83±18, Hex: 57±3 mm Hg) was reduced. After 30 min, the index of conductance at the sciatic nerve (velocity/MAP expressed as % baseline) started to increase from 103±35 to 127±39% baseline in the following 30 min (p<0.05). Infusion of NPY (Y1 agonist) minimized this dilatory response (Hex baseline: 99±15, NPY: 104±11% baseline; NS). This NPY-induced attenuation was, in turn, minimized by BIBP3226 (Hex baseline: 73±12, NPY+BIBP3226: 89±14% baseline). Neither NPY nor BIBP3226 infusions without Hex affected the sciatic nerve arterial conductance. We conclude that the late dilation following Hex which is reversed by Y1R activation suggests some level of sympathetic control over sciatic nerve blood flow.

Intrinsic microvasculature of the sciatic nerve in the rat.

Microvasculature associated with the sciatic nerve was examined using high-resolution micro-CT scanning in one group of rats and surgical exploration in another. The results indicate that blood supply to the sciatic nerve is an "open-ended" system in which the vessels run longitudinally within the epineurium and connect with external vasculature primarily at junction points. Although the range of vasculature found extended down to 4-5 µ, only a few isolated vessels of this size were found, with no capillary "mesh" as such, possibly because of the close proximity of the intrinsic vessel to nerve fibers within the epineurium. While the study did not include direct measurements of flow or nerve function, the "open-ended" pattern of vasculature found has important implications regarding the relationship between the two. Specifically, the nerve is less vulnerable to a severe or complete disruption in blood supply than it would be under a close-ended system such as that of the heart or brain, where a severe disruption can occur with the obstruction of only a single vessel. Indeed, the pattern of vasculature found, subject to further study of vasculature at the capillary level, suggests that flow within the intrinsic vessels may be in either direction, depending on circumstances, somewhat like flow within the circle of Willis in the cerebral circulation.

Rodent cardiovascular responses to baroreceptor unloading: effect of plane of anaesthesia.

The objective of this study was to determine whether a plane of urethane-α-chloralose anaesthesia that suppresses motor reflexes would affect baroreflex cardiovascular control relative to a plane of anaesthesia that leaves motor reflexes intact. Adult male Sprague-Dawley rats were anaesthetized to either a light (motor reflexes intact) or deep (motor reflexes suppressed) plane of anaesthesia. Animals were exposed to graded (-2 to -10 mm Hg) lower body negative pressure while heart rate, vascular resistance, and mean arterial pressure were assessed. No between-group differences were observed in baseline hemodynamics. Graded lower body negative pressure progressively increased heart rate (p < 0.01) and vascular resistance (p < 0.001) and reduced mean arterial pressure (p < 0.001) similarly in light and deep planes of anaesthesia. Therefore, the deep plane of anaesthesia was not associated with a degradation of the autonomic response to baroreceptor unloading beyond that observed at the light plane. These data support the use of urethane-α-chloralose anaesthesia in studies examining reflex cardiovascular control concomitant with some degree of noxious stimulation.