Grandmaternal pre-pregnancy body mass index and infant birthweight: a mediation analysis of maternal pre-pregnancy body mass index.

The objectives of this study were to examine the total effect of grandmaternal [G0] pre-pregnancy body mass index (BMI) on infant [G2] birthweight z-score and to quantify the mediation role of maternal [G1] pre-pregnancy BMI. Data were extracted from the Nova Scotia 3G Multigenerational Cohort. The association between G0 pre-pregnancy BMI and G2 birthweight z-score and the mediated effect by G1 pre-pregnancy BMI were estimated using g-computation with adjustment for confounders identified using a directed acyclic graph and accounting for intermediate confounding. 20822 G1-G2 dyads from 18450 G0 were included. Relative to G0 normal weight, G0 underweight decreased mean G2 birthweight z-score (-0.11, 95% confidence interval (CI) -0.20, -0.030), while G0 overweight and obesity increased mean G2 birthweight z-score (0.091 [95% CI 0.034, 0.15] and 0.22 [95% CI 0.11, 0.33]). G1 pre-pregnancy BMI partly mediated the association, with the largest effect size observed for G0 obesity (0.11, 95% CI 0.080, 0.14). Estimates of the direct effect were close to the null. In conclusion, grandmaternal pre-pregnancy BMI was associated with infant birthweight z-score. Maternal pre-pregnancy BMI partly mediated the association, suggesting that factors related to BMI may play an important role in the transmission of weight across the maternal line.

Antenatal Corticosteroid Prophylaxis at Late Preterm Gestation: Clinical Guidelines Versus Clinical Practice.

OBJECTIVE: 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 U.S. from 2007 to 2020. Antenatal corticosteroids (ACS) administration within specific categories of gestational age was assessed by calculating rates per 100 live births, and temporal changes were quantified using odds ratio (OR) and 95% confidence intervals (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.

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.

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.

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.

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.

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.

Directive clinique no 425a : Le cannabis aux différentes périodes de la vie des femmes - Partie 1 : Fertilité, contraception, ménopause et douleur pelvienne.

OBJECTIF: Fournir aux fournisseurs de soins de santé les meilleures données probantes sur l'utilisation de cannabis et la santé des femmes. Les domaines d'intérêt sont : les profils généraux d'utilisation du cannabis ainsi que la sécurité de la consommation; les soins aux femmes qui utilisent le cannabis; la stigmatisation; le dépistage, l'intervention brève et l'orientation vers le traitement; les effets sur la régulation hormonale; la santé reproductive, y compris la contraception et la fertilité; la fonction sexuelle; les effets sur les symptômes périménopausiques et postménopausiques; et l'utilisation dans le traitement des syndromes de douleur pelvienne chronique. POPULATION CIBLE: La population cible comprend toutes les femmes qui consomment ou utilisent du cannabis ou qui envisagent de le faire. RéSULTATS: Un dialogue ouvert et fondé sur des données probantes relativement à l'utilisation et la consommation de cannabis, dialogue qui mènera à l'amélioration des soins aux patientes. BéNéFICES, RISQUES ET COûTS: L'exploration de l'utilisation et de la consommation de cannabis par une approche basée sur la connaissance des traumatismes donne l'occasion au fournisseur de soins et à la patiente de créer une solide alliance thérapeutique collaborative. Cette alliance permet aux femmes de faire des choix éclairés sur leurs propres soins. Elle facilite également le diagnostic et le traitement possible des troubles de l'usage du cannabis. Il ne faut pas stigmatiser la consommation, car la stigmatisation nuit à l'alliance thérapeutique (c'est-à-dire le partenariat entre la patiente et le fournisseur de soins). Plusieurs effets indésirables de la consommation de cannabis peuvent être confondus avec d'autres problèmes de santé. À l'heure actuelle, l'utilisation du cannabis pour traiter les problèmes de santé féminine n'est pas financée par le secteur public; par conséquent, les utilisatrices doivent assumer les coûts directs. Les coûts indirects de l'utilisation de cannabis sont inconnus. Ainsi, les fournisseurs de soins et les patientes doivent comprendre le rôle du cannabis dans les problèmes de santé féminine de sorte que les femmes puissent prendre des décisions éclairées. DONNéES PROBANTES: Des recherches ont été effectuées dans PubMed, Embase et la littérature grise pour recenser des études publiées entre le 1er janvier 2018 et le 18 février 2021 concernant l'utilisation du cannabis et ses effets sur l'infertilité, la contraception, les symptômes périménopausiques et postménopausiques et la douleur pelvienne. Toutes les publications des types suivants ont été incluses : essais cliniques, études observationnelles, revues (y compris les revues systématiques et les méta-analyses), directives cliniques et déclarations de conférences de consensus. Un survol des publications a été effectué pour en confirmer la pertinence. Les termes de recherche ont été définis à l'aide des termes MeSH (Medical Subject Headings) et mots clés (et variantes) suivants : cannabis, cannabinoids, marijuana, dexanabinol, dronabinol et tetrahydrocannabinol. À ces termes ont été combinés les termes suivants afin de cerner la santé des femmes : estrogen, estradiol, medroxyprogesterone acetate, vaginal contraception, oral contraceptives, fertilization, amenorrhea, oligomenorrhea, pelvic pain, dysmenorrhea, endometriosis, interstitial cystitis, vulvodynia et menopause. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant l'approche d'évaluation, de développement et d'évaluation (GRADE). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins de santé qui prodiguent des soins aux femmes. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

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.

Directive clinique no 425b : Le cannabis aux différentes périodes de la vie des femmes - Partie 2 : Grossesse, période postnatale et allaitement.

OBJECTIF: Fournir aux fournisseurs de soins les meilleures données probantes sur l'utilisation de cannabis et la santé des femmes. Les domaines d'intérêt sont le dépistage, la dépendance et le sevrage; la communication et la tenue de dossier; la grossesse (y compris les issues fœtales et maternelles); la gestion de la douleur maternelle; les soins postnataux (y compris la fumée secondaire et la parentalité); et l'allaitement. POPULATION CIBLE: Femmes enceintes, allaitantes ou qui planifient une grossesse. BéNéFICES, RISQUES ET COûTS: Discuter de l'utilisation de cannabis avec les femmes enceintes, allaitantes ou qui planifient une grossesse les aide à faire des choix éclairés. D'après des données probantes limitées, il faut éviter l'utilisation de cannabis pendant la grossesse ou l'allaitement, ou réduire la consommation au maximum si l'abstention n'est pas un objectif atteignable, étant donné l'absence de données sur l'innocuité et le suivi à long terme des grossesses et nourrissons exposés au cannabis. DONNéES PROBANTES: Les auteurs ont interrogé les bases de données PubMed et Cochrane Library pour extraire des articles sur l'utilisation de cannabis pendant la grossesse et l'allaitement publiés entre le 1er janvier 2018 et le 5 février 2021. Les termes de recherche ont été déterminés à partir de termes de recherche MeSH, de mots clés et de leurs variantes : cannabis, cannabinoids, cannabidiol, CBD, THC, marijuana, edible, pregnancy, pregnant, prenatal, perinatal, postnatal, breastfeed, breastfed, lactation, nursing, fetus, fetal, neonatal, newborn et child. Les auteurs ont inclus toutes les publications des types suivants : essais cliniques, études observationnelles, revues (y compris les revues systématiques et les méta-analyses), directives cliniques et déclarations de conférences de consensus. Les principaux critères d'inclusion étaient les femmes enceintes et allaitantes, comme population cible, et l'exposition au cannabis, comme intervention d'intérêt. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique d'évaluation, de développement et d'évaluation (GRADE). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins de santé qui prodiguent des soins aux femmes en âge de procréer. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

The Effect of Fetal Trisomy 21 on Adverse Perinatal Obstetrical Outcomes in Nova Scotia, 2000-2019.

OBJECTIVE: To understand the risks associated with trisomy 21 in pregnancy in order to inform obstetrical care and improve outcomes. METHODS: A population-based retrospective cohort study was undertaken of all pregnancies involving a fetus with trisomy 21 in Nova Scotia, Canada, from 2000 to 2019. Cases were identified from the provincial laboratory genetics database, linked to the Nova Scotia Atlee Perinatal Database for pregnancy outcomes, and compared with the general obstetrical population. RESULTS: A total of 350 pregnancies were identified, of which 23% were ongoing pregnancies in which trisomy 21 was diagnosed prenatally and 24% involved diagnoses made after delivery. Compared with the general obstetrical population, women with ongoing pregnancies affected by trisomy 21 were more likely to be older (mean age 34 vs. 29 y), multiparous (67% vs. 55%), and in a relationship (79% vs. 68%). Trisomy 21 was associated with a significantly increased risk of preterm birth (<37 weeks; 24.1% vs. 8.3%); small for gestational age (<10th percentile; 21.7% vs. 8.2%); cesarean delivery (31.5% vs. 27.1%); and combined perinatal/neonatal mortality (8.0% vs. 0.8%) (P < 0.001 for all). CONCLUSION: Trisomy 21 is associated with significant adverse perinatal and neonatal risks. Population screening to identify trisomy 21 can be used to optimize perinatal outcomes with appropriate fetal surveillance in these pregnancies.

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.

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.

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.

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.

No. 298-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.

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.

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.