Validation of Ultrasound Dating Protocols Using Data From Twins Conceived Through In Vitro Fertilization in Nova Scotia: A Retrospective Cohort Study

OBJECTIVES

Clinical practice guidelines recommend determining gestational age (GA) for twin pregnancies using the fetal crown rump length (CRL) of the larger fetus. This study investigated whether the CRL of the larger or smaller fetus at 11-14 weeks best predicted in vitro fertilization (IVF) assigned GA.

METHODS

A retrospective cohort study of twin pregnancies conceived by IVF ± intracytoplasmic sperm injection, 2004-2022, generated GA estimations for each co-twin CRL at the 11-14 week ultrasound, to determine which fetus (smaller or larger) more consistently predicted IVF-assigned GA. Monoamniotic twins and twins with known structural or vascular abnormalities were excluded. Paired t tests evaluated the ability of CRL to predict GA, and logistic regression evaluated the predictive ability of each of the co-twin groups with increasing size differences. Statistical significance was set at P < 0.05.

RESULTS

Viewpoint 6 identified 359 eligible twin pairs. CRL was closest with the smaller fetus (0.38 days); CRL for both the smaller (95% CI 0.16-0.61) and the larger (2.25 days, 95% CI 2.04-2.46) fetus showed deviation from IVF-assigned GA. As the absolute difference between the small and large fetus increased, the ultrasound-estimated GA of the smaller fetus was still consistently closer to IVF-assigned GA.

CONCLUSIONS

In this selected population of twins with known GA, the CRL of the smaller fetus more accurately predicted IVF-assigned GA even with increasing differences in fetal size. These findings provide important information for appropriately dating pregnancies to facilitate adherence to national guidelines to monitor for pregnancy complications, and plan frequency and type of fetal surveillance, as well as timing of delivery.

Guideline No. 443a: Opioid Use Throughout Women's Lifespan: Fertility, Contraception, Chronic Pain, and Menopause

OBJECTIVE

To provide health care providers with the best evidence on opioid use and women's health. Areas of focus include general patterns of opioid use and safety of use; care of women who use opioids; stigma, screening, brief intervention, and referral to treatment; hormonal regulation; reproductive health, including contraception and fertility; sexual function; perimenopausal and menopausal symptoms; and chronic pelvic pain syndromes.

TARGET POPULATION

The target population includes all women currently using or contemplating using opioids.

OUTCOMES

Open, evidence-informed dialogue about opioid use will lead to improvements in patient care and overall health.

BENEFITS, HARMS, AND COSTS

Exploring opioid use through a trauma-informed approach offers the health care provider and patient with an opportunity to build a strong, collaborative, and therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of opioid use disorders. Use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Therefore, health care providers and patients must understand the potential role of opioids in women's health (both positive and negative) to ensure informed decision-making.

EVIDENCE

A literature search was designed and carried out in PubMed and the Cochrane Library databases from August 2018 until March 2023 using following MeSH terms and keywords (and variants): opioids, illicit drugs, fertility, pregnancy, breastfeeding, and aging.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All health care providers who care for women.

TWEETABLE ABSTRACT

Opioid use can affect female reproductive function; health care providers and patients must understand the potential role of opioids in women's health to ensure informed decision-making.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Guideline No. 443b: Opioid Use Throughout Women's Lifespan: Opioid Use in Pregnancy and Breastfeeding

OBJECTIVE

To provide health care providers the best evidence on opioid use and women's health. Areas of focus include pregnancy and postpartum care.

TARGET POPULATION

The target population includes all women currently using or contemplating using opioids.

OUTCOMES

Open, evidence-informed dialogue about opioid use will improve patient care.

BENEFITS, HARMS, AND COSTS

Exploring opioid use through a trauma-informed approach provides the health care provider and patient with an opportunity to build a strong, collaborative, and therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of opioid use disorders. Opioid use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Health care providers need to understand the effect opioids can have on pregnant women and support them to make knowledgeable decisions about their health.

EVIDENCE

A literature search was designed and carried out in PubMed and the Cochrane Library databases from August 2018 until March 2023 using following MeSH terms and keywords (and variants): opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome, and breastfeeding.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

All health care providers who care for pregnant and/or post-partum women and their newborns.

TWEETABLE ABSTRACT

Opioid use during pregnancy often co-occurs with mental health issues and is associated with adverse maternal, fetal, and neonatal outcomes; treatment of opioid use disorder with agonist therapy for pregnant women can be safe during pregnancy where the risks outnumber the benefits.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Directive clinique no 443b : Opioïdes aux différentes étapes de la vie des femmes : Grossesse et allaitement

OBJECTIF

Présenter aux professionnels de la santé les données probantes concernant l'utilisation des opioïdes et la santé des femmes. Les domaines d'intérêt sont la grossesse et les soins post-partum.

POPULATION CIBLE

Toutes les femmes qui utilisent des opioïdes. RéSULTATS: Un dialogue ouvert et éclairé sur l'utilisation des opioïdes améliorera les soins aux patientes. BéNéFICES, RISQUES ET COûTS: L'exploration de l'utilisation d'opioïdes par une approche tenant compte des traumatismes antérieurs donne au professionnel de la santé et à la patiente l'occasion de bâtir une alliance solide, collaborative et thérapeutique. Cette alliance permet aux femmes de faire des choix éclairés. Elle favorise le diagnostic et le traitement possible du trouble lié à l'utilisation d'opioïdes. L'utilisation ne doit pas être stigmatisée, puisque la stigmatisation affaiblit le partenariat (le partenariat entre patiente et professionnel de la santé). Les professionnels de la santé ceus-ci doivent comprendre l'effet potentiel des opioïdes sur la santé les femmes enceintes et les aider à prendre des décisions éclairées sur leur santé. DONNéES PROBANTES: Une recherche a été conçue puis effectuée dans les bases de données PubMed et Cochrane Library pour la période d'août 2018 à mars 2023 des termes MeSH et mots clés suivants (et variantes) : opioids, opioid agonist therapy, illicit drugs, fertility, pregnancy, fetal development, neonatal abstinence syndrome et breastfeeding. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Tous les professionnels de la santé qui prodiguent des soins aux femmes et aux nouveaux-nés. RéSUMé POUR TWITTER: La consommation d'opioïdes pendant la grossesse coïncide souvent avec des problèmes de santé mentale et est associée à des conséquences néfastes pour la mère, le fœtus et le nouveau-né ; le traitement des troubles liés à la consommation d'opioïdes par agonistes peut être sûr pendant la grossesse lorsque les risques sont plus nombreux que les avantages. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Antenatal Corticosteroid Prophylaxis at Late Preterm Gestation: Clinical Guidelines vs Clinical Practice

OBJECTIVES

We investigated how the Antenatal Late Preterm Steroids (ALPS) trial findings have been translated into clinical practice in Canada and the United States (U.S.).

METHODS

The study included all live births in Nova Scotia, Canada and the United States from 2007 to 2020. ACS administration within specific categories of gestational age was assessed by calculating rates per 100 live births, and temporal changes were quantified using odds ratios (OR) and 95% CI. Temporal trends in optimal and suboptimal ACS use were also assessed.

RESULTS

In Nova Scotia, the rate of any ACS administration increased significantly among women delivering at 35⁰ to 36⁶ weeks, from 15.2% in 2007-2016 to 19.6% in 2017-2020 (OR 1.36, 95% CI 1.14-1.62). Overall, the U.S. rates were lower than the rates in Nova Scotia. In the U.S., rates of any ACS administration increased significantly across all gestational age categories: among live births at 35⁰ to 36⁶ weeks gestation, any ACS use increased from 4.1% in 2007-2016 to 18.5% in 2017-2020 (OR 5.33, 95% CI 5.28-5.38). Among infants between 24⁰ and 34⁶ weeks gestation in Nova Scotia, 32% received optimally timed ACS, while 47% received ACS with suboptimal timing. Of the women who received ACS in 2020, 34% in Canada and 20% in the U.S. delivered at ≥37 weeks.

CONCLUSION

Publication of the ALPS trial resulted in increased ACS administration at late preterm gestation in Nova Scotia, Canada and the U.S. However, a significant fraction of women receiving ACS prophylaxis delivered at term gestation.

Quantitative Determination of Campylobacter on Broilers along 22 United Kingdom Processing Lines To Identify Potential Process Control Points and Cross-Contamination from Colonized to Uncolonized Flocks

ABSTRACT

As part of a program to reduce numbers of the human pathogen Campylobacter on retail chickens, 22 broiler processing lines, representing more than 90% of UK production, were characterized by enumerating Campylobacter on pooled neck skins after exsanguination, scalding, defeathering, evisceration, crop removal, inside-outside washing, and air-chilling stages of processing. Sixteen of the processing lines investigated showed significant (P < 0.05) reductions in Campylobacter numbers because of carcass scalding. However, in all of these lines, the following defeathering stage caused a significant increase in Campylobacter contamination that effectively negated the reductions caused by scalding. On four processing lines, primary chilling also caused a significant reduction in numbers of Campylobacter. On three lines, there was a significant microbiological benefit from inside-outside washing. The stages where Campylobacter numbers were reduced require further investigation to determine the specific mechanisms responsible so that the observed pathogen reductions can be optimized and then more widely implemented. The transfer of up to 4 log CFU Campylobacter per g of neck skin from a colonized flock to a following uncolonized flock was observed. Cross-contamination was substantial and still detectable after 5,000 carcasses from an uncolonized flock had been processed. Numbers of Campylobacter recovered from the uncolonized flocks were highest on the first of the uncolonized birds to pass along the line, and in general, the numbers declined as more uncolonized birds were processed. Air sampling recovered low numbers at the processing stages monitored, indicating that airborne transmission was unlikely to be the primary transfer mechanism operating for cross-contamination between flocks.

HIGHLIGHTS

Guideline No. 425a: Cannabis Use Throughout Women's Lifespans - Part 1: Fertility, Contraception, Menopause, and Pelvic Pain

OBJECTIVE

To provide health care providers with the best evidence on cannabis use with respect to women's health. Areas of focus include general patterns of cannabis use as well as safety of use; care for women who use cannabis; stigma; screening, brief intervention, and referral to treatment; impact on hormonal regulation; reproductive health, including contraception and fertility; sexual function; effects on perimenopausal and menopausal symptoms; and use in chronic pelvic pain syndromes.

TARGET POPULATION

The target population includes all women currently using or contemplating using cannabis.

OUTCOMES

Open, evidence-informed dialogue about cannabis use, which will lead to improvement in patient care.

BENEFITS, HARMS, AND COSTS

Exploring cannabis use through a trauma-informed approach provides the health care provider and patient with an opportunity to build a strong, collaborative, therapeutic alliance. This alliance empowers women to make informed choices about their own care. It also allows for the diagnosis and possible treatment of cannabis use disorders. Use should not be stigmatized, as stigma leads to poor "partnered care" (i.e., the partnership between the patient and care provider). Multiple side effects of cannabis use may be mistaken for other disorders. Currently, use of cannabis to treat women's health issues is not covered by public funding; as a result, individual users must pay the direct cost. The indirect costs of cannabis use are unknown. Thus, health care providers and patients must understand the role of cannabis in women's health issues, so that women can make knowledgeable decisions.

EVIDENCE

PubMed, EMBASE, and grey literature were searched to identify studies of "cannabis use and effect on infertility, contraception, perimenopause and menopausal symptoms, and pelvic pain" published between January 1, 2018 and February 18, 2021. All clinical trials, observational studies, reviews (including systematic reviews and meta-analyses), guidelines, and conference consensus statements were included. Publications were screened for relevance. The search terms were developed using the Medical Subject Headings (MeSH) terms and keywords (and variants), including cannabis, cannabinoids, marijuana, dexanabinol, dronabinol, tetrahydrocannabinol; the specific terms to capture women's health were estrogen, estradiol, medroxyprogesterone acetate, vaginal contraception, oral contraceptives, fertilization, amenorrhea, oligomenorrhea, pelvic pain, dysmenorrhea, endometriosis, interstitial cystitis, vulvodynia, and menopause.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All heath care providers who care for women.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Guideline No. 425b: Cannabis Use Throughout Women's Lifespans - Part 2: Pregnancy, the Postnatal Period, and Breastfeeding

OBJECTIVE

To provide health care providers with the best evidence on cannabis use and women's health. Areas of focus include screening, dependence, and withdrawal; communication and documentation; pregnancy (including maternal and fetal outcomes); maternal pain control; postpartum care (including second-hand smoking and parenting); and breastfeeding.

TARGET POPULATION

The target population includes women who are planning a pregnancy, pregnant, or breastfeeding.

BENEFITS, HARMS, AND COSTS

Discussing cannabis use with women who are planning a pregnancy, pregnant, or breastfeeding allows them to make informed choices about their cannabis use. Based on the limited evidence, cannabis use in pregnancy or while breastfeeding should be avoided, or reduced as much as possible if abstaining is not feasible, given the absence of safety and long-term follow up data on cannabis-exposed pregnancies and infants.

EVIDENCE

PubMed and Cochrane Library databases were searched for articles relevant to cannabis use during pregnancy and breastfeeding published between January 1, 2018, and February 5, 2021. The search terms were developed using the MeSH terms and keywords and their variants, including cannabis, cannabinoids, cannabidiol, CBD, THC, marijuana, edible, pregnancy, pregnant, prenatal, perinatal, postnatal, breastfeed, breastfed, lactation, nursing, fetus, fetal, neonatal, newborn, and child. In terms of publication type, all clinical trials, observational studies, reviews (including systematic reviews and meta-analyses), guidelines, and conference consensus statements were included. The main inclusion criteria were pregnant and breastfeeding women as the target population, and exposure to cannabis as the intervention of interest.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All health care providers who care for women of reproductive age.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Maternal cannabis use during pregnancy and maternal and neonatal outcomes: A retrospective cohort study

OBJECTIVE

To examine the relationship between reported prenatal cannabis use and neonatal and maternal outcomes and whether the legalisation of cannabis in Canada affected the rates of reported use or the association with maternal and neonatal outcomes.

DESIGN

Population-based retrospective cohort study.

SETTING

Routinely collected data in a real-world setting.

POPULATION

All women in the Canadian province of Nova Scotia with singleton births between 1 January 2004 and 30 June 2021.

METHODS

The association between cannabis use and maternal and neonatal outcomes was examined using generalised linear models with inverse probability weighting.

MAIN OUTCOME MEASURES

Maternal and neonatal outcomes in the peripartum and postpartum period.

RESULTS

Rates of reported cannabis use in pregnancy increased from 1.3% to 7.5% over the study period with no appreciable change in slope after legalisation in 2018. Infants of mothers reporting cannabis use in pregnancy were more likely to have major anomalies and a 5-minute Apgar score ≤7, require neonatal intensive care unit admission, and had lower birthweight, head circumference and birth length than infants of mothers not reporting cannabis use. These associations did not differ before and after legalisation.

CONCLUSIONS

Reported cannabis use during pregnancy is associated with early postnatal complications and reduced fetal growth, even after taking into account a range of confounding factors. Rates of reported cannabis use during pregnancy increased over the past 5 years in Nova Scotia with no apparent additional effect of legalisation.

The association between threatened preterm labour and perinatal outcomes at term: a population-based cohort study

OBJECTIVE

To estimate the association between threatened preterm labour (TPTL) and perinatal outcomes of infants born at term.

DESIGN

A population-based cohort study of perinatal outcomes following TPTL <37 weeks of gestation with delivery at term.

SETTING

Nova Scotia, Canada.

POPULATION

All non-anomalous, singleton pregnancies ≥37 weeks of gestation without antepartum haemorrhage from 1988 to 2019.

METHODS

Using data from the Nova Scotia Atlee Perinatal Database, TPTL was defined as pregnancies with a hospital admission between 20 and 37 weeks of gestation, with a diagnosis code denoting TPTL with administration of antenatal corticosteroids, or with administration of any tocolysis. Poisson regression models were used to estimate the risk ratios (RR) with 95% CI of maternal and perinatal outcomes in women who had an episode of TPTL relative to those who did not.

MAIN OUTCOME MEASURES

Birthweight for gestational age below the tenth centile and a composite of perinatal mortality or severe perinatal morbidity.

RESULTS

Of 256 599 term deliveries meeting the inclusion criteria, 2278 (0.9%) involved TPTL. The risks of the primary outcomes were higher among those with TPTL relative to those without: birthweight for gestational age below the tenth centile (RR 1.24, 95% CI 1.11-1.39) and the composite of perinatal mortality/severe perinatal morbidity (RR 1.33, 95% CI 1.15-1.54).

CONCLUSIONS

Although the prevalence of TPTL in term deliveries is low, affected pregnancies are at increased risk for adverse perinatal outcomes. Increased fetal surveillance should be considered in the management of pregnancies affected by TPTL.

Incidence, Intrapartum Risk Factors, and Prognosis of Neonatal Hypoxic-Ischemic Encephalopathy Among Infants Born at 35 Weeks Gestation or More

INTRODUCTION

Neonatal hypoxic-ischemic encephalopathy (HIE) is associated with neonatal mortality, acute neurological injury, and long-term neurodevelopmental disabilities; however, the association between intrapartum factors and HIE remains unclear.

METHODS

This population-based cohort study used linked obstetrical and newborn data derived from the Nova Scotia Atlee Perinatal Database (NSAPD, 1988-2015) and the AC Allen Perinatal Follow-Up Program Database (2006-2015) for all pregnancies with live, non-anomalous newborns ≥35 weeks gestation, not delivered by pre-labour cesarean section. Temporal trends in HIE incidence were described, and logistic regression estimated odds ratios (OR) with 95% confidence intervals (CI) for the association of intrapartum factors with HIE.

RESULTS

The NSAPD identified 227 HIE cases in the population of 226 711 deliveries from 1988 to 2015. Women with clinical chorioamnionitis in labour (OR 8.0; 95% CI 3.9-16), emergency cesarean delivery (OR 10; 95% CI 7.6-14), shoulder dystocia (OR 3.5; 95% CI 2.1-5.7), placental abruption (OR 18; 95% CI 11-29), and cord prolapse (OR 30; 95% CI 15-61) were more likely to have newborns with HIE. Two-thirds of newborns with HIE had an abnormal intrapartum fetal heart rate tracing. The mortality rate among infants with HIE was 27% by 3 years of age. Neurodevelopmental outcomes in the surviving infants were normal in 43% and showed severe developmental delay in 40%.

CONCLUSION

Overall, the rate of HIE was low in infants born at ≥35 weeks gestation. The identification of associated intrapartum factors should promote increased surveillance in these clinical situations and emphasize the importance of careful management to optimize newborn outcomes.

The 3G Multigenerational Cohort of Nova Scotian women and their mothers and offspring

BACKGROUND

The negative impact of exposures such as maternal obesity, excessive gestational weight gain, and hypertension in pregnancy on the health of the next generation has been well studied. Evidence from animal studies suggests that the effects of in utero exposures may persist into the second generation, but the epidemiological literature on the influence of pregnancy-related exposures across three generations in humans is sparse.

OBJECTIVES

This cohort was established to investigate associations between antenatal and perinatal exposures and health outcomes in women and their offspring.

POPULATION

The cohort includes women who were born and subsequently had their own pregnancies in the Canadian province of Nova Scotia from 1980 onward.

DESIGN

Intergenerational linkage of data in the Nova Scotia Atlee Perinatal Database was used to establish a population-based dynamic retrospective cohort.

METHODS

The cohort has prospectively collected information on sociodemographics, maternal health and health behaviours, pregnancy health and complications, and obstetrical and neonatal outcomes for two generations of women and their offspring.

PRELIMINARY RESULTS

As of October 2018, the 3G cohort included 14 978 grandmothers (born 1939-1986), 16 766 mothers or cohort women (born 1981-2003), and 28 638 children (born 1996-2018). The cohort women were generally younger than Nova Scotian women born after 1980, and as a result, characteristics associated with pregnancy at a younger age were more frequently seen in the cohort women; sampling weights will be created to account for this design effect. The cohort will be updated annually to capture future deliveries to women who are already in the cohort and women who become eligible for inclusion when they deliver their first child.

CONCLUSIONS

The 3G Multigenerational Cohort is a population-based cohort of women and their mothers and offspring, spanning a time period of 38 years, and provides the opportunity to study inter- and transgenerational associations across the maternal line.

An improved cleaning system to reduce microbial contamination of poultry transport crates in the United Kingdom

AIM

Following previous research on improving the cleaning of crates used to transport broiler chickens from the farm to the abattoir, a demonstration project was undertaken to investigate improvements in crate washing on a commercial scale.

METHODS AND RESULTS

The soak tank of a conventional crate washing system was replaced with a high-performance washer fitted with high-volume, high-pressure nozzles. The wash water could be heated, and a greatly improved filtration system ensured that the nozzles did not lose performance or become blocked. Visual cleanliness scores and microbial counts were determined for naturally contaminated crates which had been randomly assigned to different cleaning protocols.

CONCLUSIONS

When a combination of mechanical energy, heat and chemicals (i.e. detergent and disinfectant) was used, the results showed significant improvements to crate cleaning. Reductions of up to 3·6 and 3·8 log₁₀ CFU per crate base were achieved for Campylobacter and Enterobacteriaceae, respectively, along with a marked improvement in visual cleanliness.

SIGNIFICANCE AND IMPACT OF THE STUDY

Broiler transport crates may become heavily contaminated with faeces and this may contribute to the spread of disease between farms. The results of this trial may be of use in reducing the spread of zoonotic pathogens in the poultry meat supply chain.

A Randomized Controlled Trial of the Safety and Immunogenicity of Tetanus, Diphtheria, and Acellular Pertussis Vaccine Immunization During Pregnancy and Subsequent Infant Immune Response

Background

Immunization of pregnant women with tetanus-diphtheria-acellular pertussis vaccine (Tdap) provides protection against pertussis to the newborn infant.

Methods

In a randomized, controlled, observer-blind, multicenter clinical trial, we measured the safety and immunogenicity of Tdap during pregnancy and the effect on the infant's immune response to primary vaccination at 2, 4, and 6 months and booster vaccination at 12 months of age. A total of 273 women received either Tdap or tetanus-diphtheria (Td) vaccine in the third trimester and provided information for the safety analysis and samples for the immunogenicity analyses; 261 infants provided serum for the immunogenicity analyses.

Results

Rates of adverse events were similar in both groups. Infants of Tdap recipients had cord blood levels that were 21% higher than maternal levels for pertussis toxoid (PT), 13% higher for filamentous hemagglutinin (FHA), 4% higher for pertactin (PRN), and 7% higher for fimbriae (FIM). These infants had significantly higher PT antibody levels at birth and at 2 months and significantly higher FHA, PRN, and FIM antibodies at birth and 2 and 4 months, but significantly lower PT and FHA antibody levels at 6 and 7 months and significantly lower PRN and FIM antibody levels at 7 months than infants whose mothers received Td. Differences persisted prebooster at 12 months for all antigens and postbooster 1 month later for PT, FHA, and FIM.

Conclusions

This study demonstrated that Tdap during pregnancy results in higher levels of antibodies early in infancy but lower levels after the primary vaccine series.

Clinical Trials Registration

NCT00553228.

No. 276-Management of Group B Streptococcal Bacteriuria in Pregnancy

OBJECTIVE

To provide information regarding the management of group B streptococcal (GBS) bacteriuria to midwives, nurses, and physicians who are providing obstetrical care.

OUTCOMES

The outcomes considered were neonatal GBS disease, preterm birth, pyelonephritis, chorioamnionitis, and recurrence of GBS colonization.

EVIDENCE

Medline, PubMed, and the Cochrane database were searched for articles published in English to December 2010 on the topic of GBS bacteriuria in pregnancy. Bacteriuria is defined in this clinical practice guideline as the presence of bacteria in urine, regardless of the number of colony-forming units per mL (CFU/mL). Low colony counts refer to <100 000 CFU/mL, and high (significant) colony counts refer to ≥100 000 CFU/mL. Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to February 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care (Table).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify pregnancies in which it is appropriate to treat GBS bacteriuria to optimize maternal and perinatal outcomes, to reduce the occurrences of antibiotic anaphylaxis, and to prevent increases in antibiotic resistance to GBS and non-GBS pathogens. No cost-benefit analysis is provided.

RECOMMENDATIONS

Comparison of logistic regression with machine learning methods for the prediction of fetal growth abnormalities: a retrospective cohort study

BACKGROUND

While there is increasing interest in identifying pregnancies at risk for adverse outcome, existing prediction models have not adequately assessed population-based risks, and have been based on conventional regression methods. The objective of the current study was to identify predictors of fetal growth abnormalities using logistic regression and machine learning methods, and compare diagnostic properties in a population-based sample of infants.

METHODS

Data for 30,705 singleton infants born between 2009 and 2014 to mothers resident in Nova Scotia, Canada was obtained from the Nova Scotia Atlee Perinatal Database. Primary outcomes were small (SGA) and large for gestational age (LGA). Maternal characteristics pre-pregnancy and at 26 weeks were studied as predictors. Logistic regression and select machine learning methods were used to build the models, stratified by parity. Area under the curve was used to compare the models; relative importance of predictors was compared qualitatively.

RESULTS

7.9% and 13.5% of infants were SGA and LGA, respectively; 48.6% of births were to primiparous women and 51.4% were to multiparous women. Prediction of SGA and LGA was poor to fair (area under the curve 60-75%) and improved with increasing parity and pregnancy information. Smoking, previous low birthweight infant, and gestational weight gain were important predictors for SGA; pre-pregnancy body mass index, gestational weight gain, and previous macrosomic infant were the strongest predictors for LGA.

CONCLUSIONS

The machine learning methods used in this study did not offer any advantage over logistic regression in the prediction of fetal growth abnormalities. Prediction accuracy for SGA and LGA based on maternal information is poor for primiparous women and fair for multiparous women.

The impact of analgesic intervention during the second stage of labour: a retrospective cohort study

PURPOSE

The incidence of epidural top-ups received in the second stage of labour in nulliparous women and the obstetrical and neonatal implications associated with these boluses are explored in this retrospective observational study. We hypothesized that an epidural top-up in the second stage of labour reduces operative deliveries by resolving inadequate analgesia.

METHODS

A population-based cohort analysis was performed using perinatal data from 1 January 2013 through 31 December 2014. An anesthesia database provided information to determine the top-up incidence. Women with or without a top-up for second-stage duration were compared for method of delivery and neonatal characteristics using descriptive statistics. Logistic regression identified predictive factors for method of delivery.

RESULTS

Of the 1,462 women with a second stage of labour > one hour who received epidural analgesia, 105 (7%) required a top-up during the second stage of labour. Women who received a top-up were more likely to have had induction of labour and/or augmentation (89% vs 76%; odds ratio [OR], 2.43; 95% confidence interval [CI], 1.32 to 4.49; P = 0.003), a longer second stage (303 min vs 171 min; mean difference, 132 min; 95% CI, 113 to 151; P < 0.001), and more assisted vaginal (41% vs 17%; OR, 3.35; 95% CI, 2.21 to 5.1; P < 0.001) or Cesarean deliveries (26% vs 11%; OR, 3.04; 95% CI, 1.91 to 4.8; P < 0.001) than women without a top-up.

CONCLUSION

Most women who received a top-up had a vaginal (spontaneous or assisted) delivery. Compared with women without a top-up, women requiring a top-up had more predictors of difficult labour and higher rates of assisted vaginal delivery and Cesarean delivery.

Factors Associated with Trial of Labour and Mode of Delivery in Robson Group 5: A Select Group of Women With Previous Caesarean Section

OBJECTIVE

To determine the proportion of women in Robson group 5 (RG5) who were eligible for a trial of labour after Caesarean (TOLAC) and, among eligible candidates, identify determinants of having a TOLAC and subsequent vaginal delivery (VD).

METHODS

This population-based cohort study used data derived from the Nova Scotia Atlee Perinatal Database. Deliveries from 1998-2014 to women in RG5 (≥1 previous CS with a singleton term cephalic fetus) were included. Eligibility for a TOLAC was based on SOGC criteria. Multivariable logistic regression was used to identify characteristics independently associated with TOLAC and VD. The characteristics associated with VD were used in a logistic model to predict the theoretical probability of VD in women who did not have a TOLAC.

RESULTS

Of the 15 111 deliveries in RG5, 75.3% were by CS. Of the 14 763 eligible women, 5488 (37.2%) had a TOLAC, of which 3739 (68.1%) resulted in VD. Predictors of VD included high area-level income and either a CS without labour or a spontaneous VD in the preceding pregnancy. While mode of previous delivery also predicted TOLAC among eligible women, high area-level income was associated with reduced odds of TOLAC. The probability of VD in women who did not undergo TOLAC was estimated to be 47.1%, and the lowest CS rate attainable in RG5 was estimated at 46.3%.

CONCLUSIONS

Sociodemographic factors such as income and previous mode of delivery were associated with the rates of TOLAC and subsequent VD in eligible women, and suggest that the Caesarean section rate in RG5 could be safely reduced.

Incidence and Carrier Frequency of CFTR Gene Mutations in Pregnancies With Echogenic Bowel in Nova Scotia and Prince Edward Island

OBJECTIVE

Fetal echogenic bowel (echogenic bowel) is associated with cystic fibrosis (CF), with a reported incidence ranging from 1% to 13%. Prenatal testing for CF in the setting of echogenic bowel can be done by screening parental or fetal samples for pathogenic CFTR variants. If only one pathogenic variant is identified, sequencing of the CFTR gene can be undertaken, to identify a second pathogenic variant not covered in the standard screening panel. Full gene sequencing, however, also introduces the potential to identify variants of uncertain significance (VUSs) that can create counselling challenges and cause parental anxiety. To provide accurate counselling for families in the study population, the incidence of CF associated with echogenic bowel and the carrier frequency of CFTR variants were investigated.

METHODS

All pregnancies for which CF testing was undertaken for the indication of echogenic bowel (from Nova Scotia and Prince Edward Island) were identified (January 2007-July 2017). The CFTR screening and sequencing results were reviewed, and fetal outcomes related to CF were assessed.

RESULTS

A total of 463 pregnancies with echogenic bowel were tested. Four were confirmed to be affected with CF, giving an incidence of 0.9% in this cohort. The carrier frequency of CF among all parents in the cohort was 5.0% (1 in 20); however, when excluding parents of affected fetuses, the carrier frequency for the population was estimated at 4.1% (1 in 25). CFTR gene sequencing identified an additional VUS in two samples.

CONCLUSION

The incidence of CF in pregnancies with echogenic bowel in Nova Scotia and Prince Edward Island is 0.9%, with an estimated population carrier frequency of 4.1%. These results provide the basis for improved counselling to assess the risk of CF in the pregnancy, after parental carrier screening, using Bayesian probability. Counselling regarding VUSs should be undertaken before gene sequencing.

Association Between Factor V Leiden Mutation, Small for Gestational Age, and Preterm Birth: A Systematic Review and Meta-Analysis

OBJECTIVE

To estimate the association of a maternal factor V Leiden (FVL) mutation with SGA and preterm birth.

DATA SOURCES

We performed a search of PubMed, Embase, Scopus, CINAHL, and the Cochrane Library from inception to April 2016 for cohort and case-control studies of women with FVL mutation and associated outcomes of SGA and preterm birth that included a reference group without FVL mutation. Additional studies were identified from reference lists of relevant research and review articles.

STUDY SELECTION

Two authors (JKB, AMO) independently examined the abstracts of the potentially eligible studies, and full texts of eligible studies were retrieved for further evaluation. Disagreements were resolved by consensus. We identified 42 studies suitable for inclusion in the meta-analysis.

DATA EXTRACTION

Thirty-two studies evaluated SGA, and 18 studies assessed preterm birth. Study quality was assessed using the Newcastle Ottawa Scale. A random effects model with inverse variance weighting was used to calculate pooled ORs and 95% CIs. Subgroup analyses were performed by study design.

DATA SYNTHESIS

The overall OR associating FVL mutation with SGA was significant (OR 1.40, 95% CI 1.18 to 1.67). Analysis of 13 cohort studies resulted in an OR of 1.20 (95% CI 1.03 to 1.41), and data from 19 case-control studies yielded an OR of 1.86 (95% CI 1.35 to 2.56). There was no significant association between FVL mutation and preterm birth (OR 1.17, 95% CI 1.00 to 1.37) when all groups were studied, but the association was significant for case-control studies alone (OR 1.40, 95% CI 1.05 to 1.86).

CONCLUSION

There is an increased risk for SGA in pregnancies complicated by FVL mutation in both cohort and case-control study designs. The risk of preterm birth with FVL mutation is less clear, although there is conflicting evidence from cohort and case-control studies regarding the risk of preterm birth associated with FVL mutation.

Adverse Perinatal Conditions Associated With Prenatally Detected Fetal Echogenic Bowel in Nova Scotia

OBJECTIVE

This study sought to estimate the association of adverse perinatal outcomes with pregnancies complicated by fetal echogenic bowel.

METHODS

Data for pregnancies complicated with echogenic bowel identified in the second trimester were derived from the tertiary referral IWK Health Centre (Halifax, NS) Viewpoint Ultrasound Database augmented by medical chart review. The study was undertaken between 2003 and 2014. Rates of positive cytomegalovirus and toxoplasmosis infection were determined using maternal serology and amniocentesis results. Rates of intrauterine growth restriction, abnormal karyotype, cystic fibrosis, antenatal bleeding, and bowel abnormalities were also determined. Neonatal information included newborn urine culture results and postnatal genetic testing. Univariate analyses compared rates of infection with isolated echogenic bowel and echogenic bowel with other ultrasound findings, with statistical significance set at P <0.05.

RESULTS

There were 422 pregnancies identified prenatally with echogenic bowel (82% had isolated echogenic bowel). Of these, 92 (22%) had at least one of the foregoing associated abnormalities. Three percent of women had serologic test results positive for cytomegalovirus or toxoplasmosis, with <1% documented newborn infections. Cystic fibrosis and other genetic diagnoses were observed in 8%, intrauterine growth restriction in 14%, antenatal bleeding in 19%, and bowel abnormalities in 3% of the cases of echogenic bowel. Pregnancies with isolated echogenic bowel had an 80% reduction in risk for these significant outcomes, in contrast to a four- to 11-fold increased risk of specific outcomes when additional ultrasound findings were present.

CONCLUSION

An overall rate of adverse conditions of 22% with prenatally detected echogenic bowel serves to inform women and health care providers and emphasizes the importance of careful screening fetal ultrasound studies and timely referral for comprehensive assessment with findings of echogenic bowel for evaluation for associated findings.

Prévention de l'infection néonatale à streptocoques du groupe B d'apparition précoce

OBJECTIF

Analyser les données issues de la littérature et formuler des recommandations sur la prise en charge des parturientes en vue de prévenir l'infection néonatale à streptocoques du groupe B d'apparition précoce. Parmi les révisions clés que renferme la présente directive clinique mise à jour, on trouve des modifications quant aux recommandations en ce qui concerne les schémas posologiques d'antibioprophylaxie, les épreuves de sensibilité et la prise en charge des femmes présentant une rupture prématurée des membranes.

ISSUES

Parmi les issues maternelles évaluées, on trouvait l'exposition aux antibiotiques au cours de la grossesse et du travail, ainsi que les complications associées à l'administration d'antibiotiques. Les issues néonatales associées aux taux d'infection néonatale à streptocoques du groupe B d'apparition précoce ont été évaluées. RéSULTATS: La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, CINAHL et The Cochrane Library entre janvier 1980 et juillet 2012, au moyen d'un vocabulaire contrôlé et de mots clés appropriés (« group B streptococcus », « antibiotic therapy », « infection », « prevention »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles. Aucune restriction n'a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en mai 2013. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales.

VALEURS

La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau 1). AVANTAGES, DéSAVANTAGES ET COûTS: Les recommandations que renferme la présente directive clinique sont conçues de façon à aider les cliniciens à identifier et à assurer la prise en charge des grossesses exposées à un risque d'infection néonatale à streptocoques du groupe B, en vue d'optimiser les issues maternelles et périnatales. Aucune analyse de rentabilité n'est fournie. DéCLARATION SOMMAIRE: Nous disposons de bonnes données (issues d'essais comparatifs randomisés) indiquant que, chez les femmes présentant une rupture prématurée des membranes à terme qui sont colonisées par des streptocoques du groupe B, le déclenchement du travail entraîne une baisse des taux d'infection néonatale. (I) Aucune donnée ne permet de soutenir que, dans une telle situation clinique, la prise en charge non interventionniste permet l'obtention de bonnes issues néonatales. RECOMMANDATIONS.

The Prevention of Early-Onset Neonatal Group B Streptococcal Disease

OBJECTIVE

To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes.

OUTCOMES

Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated.

EVIDENCE

Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided.

SUMMARY STATEMENT

There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour (I). There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation.

RECOMMENDATIONS

Anesthetic Management Guided by Transthoracic Echocardiography During Cesarean Delivery Complicated by Hypertrophic Cardiomyopathy

We describe the management of a parturient woman with hypertrophic cardiomyopathy who developed a symptomatic accelerated idioventricular rhythm who required an urgent cesarean delivery at 32 weeks. Transthoracic echocardiography helped guide anesthetic management, including epidural dosing, fluid management, and phenylephrine infusion rates. This case demonstrates the application of transthoracic echocardiography to guide anesthetic management in a parturient woman at risk for cardiovascular compromise.

Type of Labour in the First Pregnancy and Cumulative Perinatal Morbidity

OBJECTIVE

To estimate cumulative perinatal morbidity among infants delivered at term, according to the type of labour in the first pregnancy, when the first pregnancy was low risk.

METHODS

In a 26-year population-based cohort study (1988-2013) using the Nova Scotia Atlee Perinatal Database, we identified the type of labour in successive pregnancies in low-risk, nulliparous women at term in their first pregnancy (who had at least one subsequent pregnancy), and also identified perinatal outcomes in subsequent deliveries according to the type of labour in the first pregnancy.

RESULTS

A total of 37 756 pregnancies satisfied inclusion and exclusion criteria; of these, 1382 (3.7%) had a Caesarean section without labour in the first pregnancy. Rates of most adverse perinatal outcomes were low (≤ 1%). The risks for stillbirth were low in subsequent deliveries, including those that followed CS without labour in the first pregnancy, and the risks for the overall severe perinatal morbidity outcome were less than 10% for all subsequent deliveries.

CONCLUSION

The absolute risks for severe perinatal morbidity outcomes in a population of low-risk women (with up to four additional pregnancies) were small, regardless of type of labour in the first pregnancy. This finding provides important information on perinatal outcomes in subsequent pregnancies when considering type of labour in the first pregnancy.

Atonic Postpartum Hemorrhage: Blood Loss, Risk Factors, and Third Stage Management

OBJECTIVE

Atonic postpartum hemorrhage rates have increased in many industrialized countries in recent years. We examined the blood loss, risk factors, and management of the third stage of labour associated with atonic postpartum hemorrhage.

METHODS

We carried out a case-control study of patients in eight tertiary care hospitals in Canada between January 2011 and December 2013. Cases were defined as women with a diagnosis of atonic postpartum hemorrhage, and controls (without postpartum hemorrhage) were matched with cases by hospital and date of delivery. Estimated blood loss, risk factors, and management of the third stage labour were compared between cases and controls. Conditional logistic regression was used to adjust for confounding.

RESULTS

The study included 383 cases and 383 controls. Cases had significantly higher mean estimated blood loss than controls. However, 16.7% of cases who delivered vaginally and 34.1% of cases who delivered by Caesarean section (CS) had a blood loss of < 500 mL and < 1000 mL, respectively; 8.2% of controls who delivered vaginally and 6.7% of controls who delivered by CS had blood loss consistent with a diagnosis of postpartum hemorrhage. Factors associated with atonic postpartum hemorrhage included known protective factors (e.g., delivery by CS) and risk factors (e.g., nulliparity, vaginal birth after CS). Uterotonic use was more common in cases than in controls (97.6% vs. 92.9%, P < 0.001). Delayed cord clamping was only used among those who delivered vaginally (7.7% cases vs. 14.6% controls, P = 0.06).

CONCLUSION

There is substantial misclassification in the diagnosis of atonic postpartum hemorrhage, and this could potentially explain the observed temporal increase in postpartum hemorrhage rates.

An Algorithm for Predicting Neonatal Mortality in Threatened Very Preterm Birth

OBJECTIVE

To develop a prediction model for neonatal mortality using information readily available in the antenatal period.

METHODS

A multiple logistic regression model of a complete population-based geographically defined cohort of very preterm infants of 23+0 to 30+6 weeks' gestation was used to identify antenatal factors which were predictive of mortality in this population. Infants lt; 23 weeks and those with major anomalies were excluded.

RESULTS

Between 1996 and 2012, 1240 live born infants lt; 31 weeks' gestation were born to women residing in Nova Scotia. Decreasing gestational age strongly predicted an increased mortality rate. Other factors significantly contributing to increased mortality included classification as small for gestational age, oligohydramnios, maternal psychiatric disorders, antenatal antibiotic therapy, and monochorionic twins. Reduced neonatal mortality was associated with antenatal use of antihypertensive agents and use of corticosteroids of any duration of therapy given at least 24 hours before delivery. An algorithm was developed to estimate the risk of mortality without the need for a calculator.

CONCLUSION

Prediction of the probability of neonatal mortality is influenced by maternal and fetal factors. An algorithm to estimate the risk of mortality facilitates counselling and informs shared decision making regarding obstetric management.

Type of Labour in the First Pregnancy and Cumulative Maternal Morbidity

OBJECTIVE

To estimate cumulative maternal morbidity among women who delivered at term in their first pregnancy on the basis of type of labour in the first pregnancy.

METHODS

Using a 25-year population-based cohort (1988 to 2012) derived from the Nova Scotia Atlee Perinatal Database, we determined the type of labour in successive pregnancies in low-risk, nulliparous women at term in their first pregnancy (who had at least one subsequent pregnancy), and the maternal outcomes in subsequent deliveries based on the type of labour in the first pregnancy.

RESULTS

A total of 36 871 pregnancies satisfied inclusion and exclusion criteria, 1346 of which were delivered by Caesarean section without labour in the first pregnancy. Rates of most adverse maternal outcomes were low (≤1%). The type of labour in the first pregnancy influenced the subsequent risk of postpartum hemorrhage and blood transfusion, and the risks increased with successive deliveries when labours were spontaneous in onset or were induced. The risks for abnormal placentation were low with subsequent deliveries, including following CS without labour in the first pregnancy, and risks for overall severe maternal morbidity were less than 10% for all subsequent deliveries.

CONCLUSION

The absolute risks for severe maternal morbidity outcomes in a population of women without a high number of subsequent pregnancies were small (regardless of type of labour in the first pregnancy); this provides important information for women, families, and caregivers when considering pregnancy outcomes related to type of labour.

A longitudinal observational study of Salmonella shedding patterns by commercial turkeys during rearing and fattening, showing limitations of some control measures

1. The onset and progression of Salmonella infections was investigated in commercial turkey flocks from placement at 1 d old until slaughter in "brood and move" systems using a longitudinal observational approach based on faeces and environmental sampling with subsequent culture of Salmonella. 2. Persistent Salmonella Newport contamination was found within rearing houses and on their external concrete aprons after cleaning and disinfection between crops of heavily shedding young birds. 3. Salmonella shedding was often detected by 5 d of age and the frequency of positive samples peaked at 14-35 d. Thereafter Salmonella isolations declined, especially in the later (fattening) stages. Samples were still Salmonella-positive at low prevalence in half of the intensively sampled houses at slaughter age. 4. A number of management interventions to combat Salmonella infection of flocks, including sourcing policy, competitive exclusion cultures and cleaning and disinfection, were inadequate to prevent flock infection, although improved disinfection on one unit was associated with a delay in the onset of flock infection.

Influenza vaccination and fetal and neonatal outcomes

As pregnant women are considered a high-risk group for severe influenza illness, current recommendations advise vaccination of all pregnant women with inactivated influenza vaccine. Nevertheless, rates of maternal influenza vaccination have historically been low, possibly reflecting ongoing concerns about vaccine safety. Until recently, the majority of evidence concerning safety of influenza vaccination during pregnancy was limited to post-marketing pharmacovigilance studies; however, in the past 5 years, one randomized clinical trial and a number of observational studies reflecting seasonal trivalent inactivated influenza vaccines and monovalent H1N1 influenza vaccines have been published. This review summarizes the evidence pertaining to fetal and neonatal outcomes following influenza vaccination during pregnancy for comparative analytic studies published between 2008 and August 2013. Since the majority of these studies are observational in nature, issues related to study quality are also addressed.

Trends in the prevalence of cerebral palsy among very preterm infants (<31 weeks' gestational age)

BACKGROUND

The birth prevalence of cerebral palsy varies over time among very preterm infants, and the reasons are poorly understood.

OBJECTIVE

To describe the variation in the prevalence of cerebral palsy among very preterm infants over time, and to relate these differences to other maternal or neonatal factors.

METHODS

A population-based cohort of very preterm infants was evaluated over a 20-year period (1988 to 2007) divided into four equal epochs.

RESULTS

The prevalence of cerebral palsy peaked in the third epoch (1998 to 2002) while mortality rate peaked in the second epoch (1993 to 1997). Maternal anemia, tocolytic use and neonatal need for home oxygen were highest in the third epoch.

CONCLUSIONS

Lower mortality rates did not correlate well with the prevalence of cerebral palsy. Maternal risk factors, anemia and tocolytic use, and the newborn need for home oxygen were highest during the same epoch as the peak prevalence of cerebral palsy.

Understanding, teaching and assessing the elements of the CanMEDS Professional Role: canadian program directors' views

BACKGROUND

Physicians are required to maintain and sustain professional roles during their careers, making the Professional Role an important component of postgraduate education. Despite this, this role remains difficult to define, teach and assess.

OBJECTIVE

To (a) understand what program directors felt were key elements of the CanMEDS Professional Role and (b) identify the teaching and assessment methods they used.

METHODS

A two-step sequential mixed method design using a survey and semi-structured interviews with Canadian program directors.

RESULTS

Forty-six program directors (48% response rate) completed the questionnaire and 10 participated in interviews. Participants rated integrity and honesty as the most important elements of the Role (96%) but most difficult to teach. There was a lack of congruence between elements perceived to be most important and most frequently taught. Role modeling was the most common way of informally teaching professionalism (98%). Assessments were most often through direct feedback from faculty (98%) and feedback from other health professionals and residents (61%). Portfolios (24%) were the least used form of assessment, but they allowed residents to reflect and stimulated self-assessment.

CONCLUSION

Program directors believe elements of the Role are difficult to teach and assess. Providing faculty with skills for teaching/assessing the Role and evaluating effectiveness in changing attitudes/behaviors should be a priority in postgraduate programs.

Transversus abdominis plane block does not improve early or late pain outcomes after Cesarean delivery: a randomized controlled trial

OBJECTIVES

Cesarean delivery is a common surgical procedure with anticipated substantial postoperative pain. The addition of a transversus abdominis plane block (TAPB) to a multimodal analgesic regimen that includes intrathecal morphine may provide improved early pain outcomes and decrease the risk of chronic post-surgical pain. The purpose of this research was to assess the ability of an ultrasound-guided TAPB with low-dose ropivacaine to decrease early postoperative pain, opioid consumption, and risk of developing persistent pain when compared with a placebo block.

METHODS

Eighty-three women were randomly assigned to either a treatment (0.25% ropivacaine) or control group (0.9% saline) in this double-blind trial, and 74 women were included in the final analysis. Ultrasound-guided TAPBs were performed with an injection of 20 mL of study solution per side. The primary outcome measures of this study were: pain at rest and pain after movement measured with a numeric rating scale, results of the Quality of Recovery-40 (QoR-40) questionnaire, and opioid consumption at 24 hr. These were used with an a priori sample size calculation to detect a 30% reduction in pain scores, a 10% improvement in QoR-40 score, and a 50% reduction in opioid consumption. Health quality and physical functioning were assessed using the Short Form 36 (SF-36®) Health Survey at 30 days and six months.

RESULTS

Assessment at 24 hr after Cesarean delivery revealed no clinically important differences between groups in postoperative pain, QoR-40, or opioid consumption. There were no clinically important differences between groups regarding measures of nausea, pruritus, vomiting, urine retention (2, 24, and 48 hr postoperatively), 24-hr QoR-40 sub-dimensions, or the SF-36 Health Survey (30 days and six months postoperatively).

CONCLUSIONS

Ultrasound-guided TAPB did not improve postoperative pain, quality of recovery, or opioid consumption 24 hr following surgery. Similar health and functioning (SF-36) at 30 days and six months were reported by both groups. This trial was registered at ClinicalTrials.gov number: NCT01261637.

Effects of socioeconomic position and clinical risk factors on spontaneous and iatrogenic preterm birth

BACKGROUND

The literature shows a variable and inconsistent relationship between socioeconomic position and preterm birth. We examined risk factors for spontaneous and iatrogenic preterm birth, with a focus on socioeconomic position and clinical risk factors, in order to explain the observed inconsistency.

METHODS

We carried out a retrospective population-based cohort study of all singleton deliveries in Nova Scotia from 1988 to 2003. Data were obtained from the Nova Scotia Atlee Perinatal Database and the federal income tax T1 Family Files. Separate logistic models were used to quantify the association between socioeconomic position, clinical risk factors and spontaneous preterm birth and iatrogenic preterm birth.

RESULTS

The study population included 132,714 singleton deliveries and the rate of preterm birth was 5.5%. Preterm birth rates were significantly higher among the women in the lowest (versus the highest) family income group for spontaneous (rate ratio 1.14, 95% confidence interval (CI) 1.03, 1.25) but not iatrogenic preterm birth (rate ratio 0.95, 95% CI 0.75, 1.19). Adjustment for maternal characteristics attenuated the family income-spontaneous preterm birth relationship but strengthened the relationship with iatrogenic preterm birth. Clinical risk factors such as hypertension were differentially associated with spontaneous (rate ratio 3.92, 95% CI 3.47, 4.44) and iatrogenic preterm (rate ratio 14.1, 95% CI 11.4, 17.4) but factors such as diabetes mellitus were not (rate ratio 4.38, 95% CI 3.21, 5.99 for spontaneous and 4.02, 95% CI 2.07, 7.80 for iatrogenic preterm birth).

CONCLUSIONS

Socioeconomic position and clinical risk factors have different effects on spontaneous and iatrogenic preterm. Recent temporal increases in iatrogenic preterm birth appear to be responsible for the inconsistent relationship between socioeconomic position and preterm birth.

Magnitude of income-related disparities in adverse perinatal outcomes

BACKGROUND

To assess and compare multiple measurements of socioeconomic position (SEP) in order to determine the relationship with adverse perinatal outcomes across various contexts.

METHODS

A birth registry, the Nova Scotia Atlee Perinatal Database, was confidentially linked to income tax and related information for the year in which delivery occurred. Multiple logistic regression was used to examine odds ratios between multiple indicators of SEP and multiple adverse perinatal outcomes in 117734 singleton births between 1988 and 2003. Models for after tax family income were also adjusted for neighborhood deprivation to gauge the relative magnitude of effects related to SEP at both levels. Effects of SEP were stratified by single- versus multiple-parent family composition, and by urban versus rural location of residence.

RESULTS

The risk of small for gestational age and spontaneous preterm birth was higher across all the indicators of lower SEP, while risk for large for gestational age was lower across indicators of lower SEP. Higher risk of postneonatal death was demonstrated for several measures of lower SEP. Higher material deprivation in the neighborhood of residence was associated with increased risk for perinatal death, small for gestational age birth, and iatrogenic and spontaneous preterm birth. Family composition and urbanicity were shown to modify the association between income and some perinatal outcomes.

CONCLUSIONS

This study highlights the importance of understanding the definitions of SEP and the mechanisms that lead to the association between income and poor perinatal outcomes, and broadening the types of SEP measures used in some cases.

The prevention of early-onset neonatal group B streptococcal disease

OBJECTIVE

To review the evidence in the literature and to provide recommendations on the management of pregnant women in labour for the prevention of early-onset neonatal group B streptococcal disease. The key revisions in this updated guideline include changed recommendations for regimens for antibiotic prophylaxis, susceptibility testing, and management of women with pre-labour rupture of membranes.

OUTCOMES

Maternal outcomes evaluated included exposure to antibiotics in pregnancy and labour and complications related to antibiotic use. Neonatal outcomes of rates of early-onset group B streptococcal infections are evaluated.

EVIDENCE

Published literature was retrieved through searches of MEDLINE, CINAHL, and The Cochrane Library from January 1980 to July 2012 using appropriate controlled vocabulary and key words (group B streptococcus, antibiotic therapy, infection, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to May 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify and manage pregnancies at risk for neonatal group B streptococcal disease to optimize maternal and perinatal outcomes. No cost-benefit analysis is provided.

SUMMARY STATEMENT

There is good evidence based on randomized control trial data that in women with pre-labour rupture of membranes at term who are colonized with group B streptococcus, rates of neonatal infection are reduced with induction of labour. (I) There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation.

RECOMMENDATIONS

1. Offer all women screening for colonization with group B streptococcus at 35 to 37 weeks' gestation with culture taken from one swab first to the vagina and then to the rectum (through the anal sphincter). (II-1A) This includes women with planned Caesarean delivery because of their risk of labour or ruptured membranes earlier than the scheduled Caesarean delivery. (II-2B) 2. Because of the association of heavy colonization with early onset neonatal disease, provide intravenous antibiotic prophylaxis for group B streptococcus at the onset of labour or rupture of the membranes to: • any woman positive for group B streptococcus by vaginal/rectal swab culture screening done at 35 to 37 weeks' gestation (II-2B); • any woman with an infant previously infected with group B streptococcus (II-3B); • any woman with documented group B streptococcus bacteriuria (regardless of level of colony-forming units) in the current pregnancy. (II-2A) 3. Manage all women who are < 37 weeks' gestation and in labour or with rupture of membranes with intravenous group B streptococcus antibiotic prophylaxis for a minimum of 48 hours, unless there has been a negative vaginal/rectal swab culture or rapid nucleic acid-based test within the previous 5 weeks. (II-3A) 4. Treat all women with intrapartum fever and signs of chorioamnionitis with broad spectrum intravenous antibiotics targeting chorioamnionitis and including coverage for group B streptococcus, regardless of group B streptococcus status and gestational age. (II-2A) 5. Request antibiotic susceptibility testing on group B streptococcus-positive urine and vaginal/rectal swab cultures in women who are thought to have a significant risk of anaphylaxis from penicillin. (II-1A) 6. If a woman with pre-labour rupture of membranes at ≥ 37 weeks' gestation is positive for group B streptococcus by vaginal/rectal swab culture screening, has had group B streptococcus bacteriuria in the current pregnancy, or has had an infant previously affected by group B streptococcus disease, administer intravenous group B streptococcus antibiotic prophylaxis. Immediate obstetrical delivery (such as induction of labour) is indicated, as described in the Induction of Labour guideline published by the Society of Obstetricians and Gynaecologist in September 2013. (II-2B) 7. At ≥ 37 weeks' gestation, if group B streptococcus colonization status is unknown and the 35- to 37-week culture was not performed or the result is unavailable and the membranes have been ruptured for greater than 18 hours, administer intravenous group B streptococcus antibiotic prophylaxis. (II-2B) 8. If a woman with pre-labour rupture of membranes at < 37 weeks' gestation has an unknown or positive group B streptococcus culture status, administer intravenous group B streptococcus prophylaxis for 48 hours, as well as other antibiotics if indicated, while awaiting spontaneous or obstetrically indicated labour. (II-3B).