The effect of changing screening practices and demographics on the incidence of gestational diabetes in British Columbia, 2005-2019.

BACKGROUND: Rates of gestational diabetes are reported to be increasing in many jurisdictions, but the reasons for this are poorly understood. We sought to evaluate the relative contribution of screening practices for gestational diabetes (including completion and methods of screening) and population characteristics to risk of gestational diabetes in British Columbia, Canada, from 2005 to 2019. METHODS: We used a population-based cohort from a provincial registry of perinatal data, linked to laboratory billing records. We used data on screening completion, screening method (1-step 75-g glucose test or 2-step approach of 50-g glucose screening test, followed by a diagnostic test for patients who screen positive) and demographic risk factors. We modelled predicted annual risk for gestational diabetes, sequentially adjusted for screening completion, screening method and risk factors. RESULTS: We included 551 457 pregnancies in the study cohort. The incidence of gestational diabetes more than doubled over the study period, from 7.2% in 2005 to 14.7% in 2019. Screening completion increased from 87.2% in 2005 to 95.5% in 2019. Use of 1-step screening methods increased from 0.0% in 2005 to 39.5% in 2019 among those who were screened. Unadjusted models estimated a 2.04 (95% confidence interval [CI] 1.94-2.13) increased risk of gestational diabetes in 2019 (v. 2005). This increase was 1.89 (95% CI 1.81-1.98) after accounting for the rise in screening completion and 1.34 (95% CI 1.28-1.40) after accounting for changes in screening methods. Further accounting for demographic risk factors (e.g., age, body mass index, prenatal care) had a small impact (increase of 1.25, 95% CI 1.19-1.31). INTERPRETATION: Most of the observed increase in the incidence of gestational diabetes was attributable to changes in screening practices (primarily changes in screening methods) rather than changing population factors. Our findings highlight the importance of understanding variation in screening practices when monitoring incidence rates for gestational diabetes.

Trends in Gestational Diabetes Screening Practices in British Columbia from 2005-2019.

OBJECTIVES: To examine trends in the frequency and method (one-step vs. two-step) of gestational diabetes mellitus (GDM) screening in British Columbia (BC), Canada, across subgroups of pregnant individuals in the context of changing local and national clinical practice guidelines. METHODS: We conducted a retrospective cohort study using de-identified, linked perinatal and laboratory billing data. We included all pregnancies delivered in BC after 28 weeks gestation, with screening dates between June 2004 and May 2019. We calculated the prevalence of each screening method with 95% CI overall and over time, and we examined screening practices in subgroups and different geographic regions. In October 2010, BC began recommending a one-step method; therefore, we examined time periods relative to this and other Canadian guideline changes. RESULTS: Screening completion increased over the study period, from 88% in 2004 to 96% in 2019. After a guideline change in 2010, use of one-step screening increased sharply from 2.0% (95% CI 1.9-2.0) to 45.2% (95% CI 44.9-45.6). Following the 2013 Diabetes Canada guideline change, one-step screening decreased to 42.8% (95% CI 42.5-43.1). Of those receiving one-step screening, 18% were diagnosed with GDM compared to 9% with two-step screening. Use of one-step screening was higher in pregnant people with risk factors and in larger urban centres. CONCLUSION: GDM screening in BC demonstrated higher use of one-step screening among people with risk factors; however, there were strong regional disparities and considerable variation in screening practices over time and across subgroups.

No. 384-Management of Breech Presentation at Term.

OBJECTIVES: To discern the risks and benefits of planned vaginal breech birth versus planned Caesarean section and to recommend selection criteria, intrapartum management parameters, and delivery techniques for vaginal breech birth. OPTIONS: Planned vaginal breech birth or planned Caesarean section for women with a singleton breech fetus at term. OUTCOMES: Perinatal mortality, short- and long-term neonatal/infant morbidity, maternal mortality, and short- and long-term maternal morbidity. EVIDENCE: Medline was searched up to April, 2018 for randomized trials and cohort studies comparing outcomes after planned vaginal breech birth and planned Caesarean section and for cohort studies comparing vaginal breech birth techniques. Additional articles were identified through bibliography tracing. VALIDATION: This guideline was peer reviewed by international clinicians with expertise in vaginal breech birth and compared with the 2017 Royal College of Obstetricians and Gynaecologists Green Top Guideline 20b: Management of Breech Presentation. The content and recommendations were drafted and agreed upon by the principal authors. The Board of the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology framework. SPONSORS: The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: RECOMMENDATIONS: Labour Selection Criteria Labour Management Delivery Technique Setting and Consent.

No 384 - Prise en charge de la présentation du siège du fœtus à terme.

OBJECTIFS: Déterminer les risques et les avantages de l'accouchement du siège par voie vaginale planifié par rapport à la césarienne planifiée et recommander des critères de sélection, des paramètres de prise en charge intrapartum et des techniques d'accouchement du siège par voie vaginale. OPTIONS: Accouchement du siège par voie vaginale planifié ou césarienne planifiée en cas de grossesse monofœtale à terme. ISSUES: Mortalité périnatale, morbidité néonatale et infantile à court et à long terme, mortalité maternelle et morbidité maternelle à court et à long terme. DONNéES PROBANTES: Des recherches ont été effectuées dans la base de données Medline jusqu'à avril 2018 pour trouver des essais randomisés et des études de cohortes qui comparent les issues après l'accouchement du siège par voie vaginale planifié et la césarienne planifiée, ainsi que des études de cohortes qui comparent les techniques d'accouchement du siège par voie vaginale. Des articles supplémentaires ont été repérés dans les bibliographies. VALIDATION: L'évaluation par les pairs de la présente directive clinique a été réalisée par des cliniciens internationaux experts en accouchement du siège par voie vaginale; la directive a également été comparée à la ligne directrice du Royal College of Obstetricians and Gynecologists, Green-top Guideline No 20b : Management of Breech Presentation. Le contenu et les recommandations ont été rédigés et acceptés par les auteurs principaux. Le conseil d'administration de la Société des obstétriciens et gynécologues du Canada a approuvé la version définitive aux fins de publication. La qualité des données probantes utilisées dans le présent document a été évaluée au moyen des critères du cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). PROMOTEURS: Société des obstétriciens et gynécologues du Canada. DéCLARATIONS SOMMAIRES: RECOMMANDATIONS: Critères de sélection du travailPrise en charge du travailTechnique d'accouchementSituation et consentement.

Venous thromboembolism prophylaxis may cause more harm than benefit: an evidence-based analysis of Canadian and international guidelines.

A majority of deep vein thromboses identified in screening studies of hospitalized patients remain clinically insignificant. Guidelines based on these studies markedly overestimate the risk of clinical venous thromboembolism (VTE) and the benefit of heparin prophylaxis. Accordingly, in 2012, the American College of Chest Physicians (ACCP) removed screening studies from the 9th edition of its Antithrombotic and Thrombolytic Therapy guideline (AT9), and downgraded recommendations. Involvement of authors of the 8th edition (AT8) was restricted due to financial and intellectual conflicts of interest. However, the first author of AT8 subsequently wrote a "Getting Started Kit," widely distributed to help Canadian hospitals develop VTE protocols. Based on screening studies reporting asymptomatic VTE, it lacks estimates of the magnitudes of benefit or harm from low molecular weight heparin (LMWH), yet advises prophylaxis in almost all hospitalized patients. Most Canadian hospitals have implemented guidelines based on this kit. Guidelines from the U. K National Institute for Health and Care Excellence and the U.S. Agency for Healthcare Research and Quality recommend a similar approach. However, a critical review of evidence reveals that most hospitalized patients have a risk of clinical VTE equal to or lower than the bleeding risk from LMWH. Most hospitalized patients should not receive LMWH until and unless randomized trials show more benefit than harm. Guidelines recommending liberal LMWH prophylaxis in hospitalized patients are not evidence based and should be critically re-examined.

An evaluation of the guidelines of the Society of Obstetricians and Gynaecologists of Canada.

Clinical practice guidelines hope to offer unbiased, evidence-based guidance for clinicians. This paper examines levels of evidence contained within the guidelines of the Society of Obstetricians and Gynaecologists of Canada and compares classification of the recommendation (CoR) A/B/C/D/E/L (derived from evidence and consensus) versus quality of evidence assessment (QoEA) I-III. 1250 recommendations were analysed and 43% of recommendations were graded as "good" evidence, the highest grade of CoR, while just 24.6% of recommendations were based on the highest level of QoEA (level I). The paper discusses possible reasons for this discrepancy. The authors hope that this analysis promotes greater transparency in evidence-based medicine ultimately leading to using the best quality of evidence available yet taking into account any areas of scientific uncertainty. This will enhance respectful care of patients, while taking into account their autonomy and furthering the cause of patient centre care.

Two-step delivery may avoid shoulder dystocia: head-to-body delivery interval is less important than we think.

A belief that prolonged head-to-body delivery interval endangers the newborn underpins the common obstetrical practice of delivering the baby's trunk immediately after the head is born. Without intervention, however, birth typically occurs in two steps: once the fetal head is delivered there is usually a pause, and the rest of the infant is born with the next contraction. Allowing a two-step delivery does not increase the risk of fetal harm, and may lower the incidence of shoulder dystocia. A two-step approach to delivery should be considered physiologically normal. This has implications for the definition of shoulder dystocia.

L'opinion selon laquelle la vie du nouveau-né est mise en danger lorsque l'intervalle entre l'accouchement de la tête fœtale et celui du reste du corps est prolongé est à l'origine de la pratique obstétricale courante qui cherche à accoucher le tronc fœtal immédiatement après l'accouchement de la tête. Toutefois, en l'absence d'intervention, l'accouchement se déroule généralement en deux étapes : une pause suit habituellement l'accouchement de la tête, puis le reste du corps est accouché au moment de la contraction suivante. Le fait de permettre un tel accouchement en deux étapes ne donne pas lieu à une hausse des risques auxquels le fœtus est exposé et pourrait même abaisser l'incidence de la dystocie de l'épaule. L'approche en deux étapes envers l'accouchement devrait être considérée comme étant physiologiquement normale; il en résulte donc des répercussions pour ce qui est de la définition de la dystocie de l'épaule.

Weight gain in pregnancy and infant birthweight after the onset of the COVID-19 pandemic: an interrupted time series analysis.

BACKGROUND: Increased weight gain and decreased physical activity have been reported in some populations since the coronavirus disease 2019 (COVID-19) pandemic, but this has not been well characterized in pregnant populations. OBJECTIVES: Our objective was to characterize the impact of the COVID-19 pandemic and associated countermeasures on pregnancy weight gain and infant birthweight in a US cohort. METHODS: Washington State pregnancies and births (1 January, 2016 to 28 December, 2020) from a multihospital quality improvement organization were examined for pregnancy weight gain, pregnancy weight gain z-score adjusted for pregestational BMI and gestational age, and infant birthweight z-score, using an interrupted time series design that controls for underlying time trends. We used mixed-effect linear regression models, controlled for seasonality and clustered at the hospital level, to model the weekly time trends and changes on 23 March, 2020, the onset of local COVID-19 countermeasures. RESULTS: Our analysis included 77,411 pregnant people and 104,936 infants with complete outcome data. The mean pregnancy weight gain was 12.1 kg (z-score: -0.14) during the prepandemic time period (March to December 2019) and increased to 12.4 kg (z-score: -0.09) after the onset of the pandemic (March to December 2020). Our time series analysis found that after the pandemic onset, the mean weight gain increased by 0.49 kg (95% CI: 0.25, 0.73 kg) and weight gain z-score increased by 0.080 (95% CI: 0.03, 0.13), with no changes in the baseline yearly trend. Infant birthweight z-scores were unchanged (-0.004; 95% CI: -0.04, 0.03). Overall, the results were unchanged in analyses stratified by pregestational BMI categories. CONCLUSIONS: We observed a modest increase in weight gain after the onset of the pandemic among pregnant people but no changes in infant birthweights. This weight change could be more important in high BMI subgroups.

Quantifying VBAC risk: muddying the waters.

The Landon et al and the Crowther et al papers are both prospective trials comparing planned vaginal birth after a previous cesarean section (VBAC) with elective cesarean section in women eligible for a trial of labor. With 33,000 women, the cohort studied by Landon et al in conjunction with the National Institute of Child Health and Human Development (NICHHD) spawned multiple publications, giving estimates of VBAC risks and success relevant to women in a wide variety of clinical situations. Data abstraction was careful and outcomes were hard and verified. With 2,300 women, the study by Crowther et al, was 6 percent the size of the Landon-NICHHD study. Although it claimed "increased risk of both fetal death or liveborn infant death prior to discharge or serious infant outcome," there were only 2 perinatal deaths-both stillbirths prior to 39 weeks' gestation and unrelated to mode of delivery. Of the 28 infants with "serious neonatal morbidity," only three could have resulted from uterine rupture; prior experience with this outcome indicates all three will likely escape long-term morbidity. Pseudorandomization and erroneous adherence to an intention-to-treat principle seriously hinder the study's internal validity, attributing outcomes for one quarter of women undergoing elective cesarean section to the planned VBAC group. The study by Landon and NICHHD is over 10 times larger and of much higher quality than the study by Crowther et al. The Landon-NICHHD publications should be used to help women make decisions about planned mode of delivery after cesarean.

Roundtable discussion: "no one can condemn you to a C-section!".

The stories in this Roundtable Discussion are related by two women whose babies were born recently in Canadian hospitals. Each woman had undergone a cesarean delivery for her first child, and whereas Sophia delivered her second baby by vaginal birth after a cesarean (VBAC), Marie was unable to find a practitioner or hospital that would allow her to have a VBAC for her second birth. The women describe how they feel about their choices and experiences. Their two accounts and the issues that they raise are discussed in commentaries by a family physician, midwife, doula, and obstetrician.

Vaginal delivery of breech presentation.

OBJECTIVES: To review the physiology of breech birth; to discern the risks and benefits of a trial of labour versus planned Caesarean section; and to recommend to obstetricians, family physicians, midwives, obstetrical nurses, anaesthesiologists, pediatricians, and other health care providers selection criteria, intrapartum management parameters, and delivery techniques for a trial of vaginal breech birth. OPTIONS: Trial of labour in an appropriate setting or delivery by pre-emptive Caesarean section for women with a singleton breech fetus at term. OUTCOMES: Reduced perinatal mortality, short-term neonatal morbidity, long-term infant morbidity, and short- and long-term maternal morbidity and mortality. EVIDENCE: Medline was searched for randomized trials, prospective cohort studies, and selected retrospective cohort studies comparing planned Caesarean section with a planned trial of labour; selected epidemiological studies comparing delivery by Caesarean section with vaginal breech delivery; and studies comparing long-term outcomes in breech infants born vaginally or by Caesarean section. Additional articles were identified through bibliography tracing up to June 1, 2008. VALUES: The evidence collected was reviewed by the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the criteria and classifications of the Canadian Task Force on Preventive Health Care. VALIDATION: This guideline was compared with the 2006 American College of Obstetrician's Committee Opinion on the mode of term singleton breech delivery and with the 2006 Royal College of Obstetrician and Gynaecologists Green Top Guideline: The Management of Breech Presentation. The document was reviewed by Canadian and International clinicians with particular expertise in breech vaginal delivery. SPONSORS: The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENTS: 1. Vaginal breech birth can be associated with a higher risk of perinatal mortality and short-term neonatal morbidity than elective Caesarean section. (I) 2. Careful case selection and labour management in a modern obstetrical setting may achieve a level of safety similar to elective Caesarean section. (II-1) 3. Planned vaginal delivery is reasonable in selected women with a term singleton breech fetus. (I) 4. With careful case selection and labour management, perinatal mortality occurs in approximately 2 per 1000 births and serious short-term neonatal morbidity in approximately 2% of breech infants. Many recent retrospective and prospective reports of vaginal breech delivery that follow specific protocols have noted excellent neonatal outcomes. (II-1) 5. Long-term neurological infant outcomes do not differ by planned mode of delivery even in the presence of serious short-term neonatal morbidity. (I) RECOMMENDATIONS: LABOUR SELECTION CRITERIA: 1. For a woman with suspected breech presentation, pre- or early labour ultrasound should be performed to assess type of breech presentation, fetal growth and estimated weight, and attitude of fetal head. If ultrasound is not available, Caesarean section is recommended. (II-1A) 2. Contraindications to labour include a. Cord presentation (II-3A) b. Fetal growth restriction or macrosomia (I-A) c. Any presentation other than a frank or complete breech with a flexed or neutral head attitude (III-B) d. Clinically inadequate maternal pelvis (III-B) e. Fetal anomaly incompatible with vaginal delivery (III-B) 3. Vaginal breech delivery can be offered when the estimated fetal weight is between 2500 g and 4000 g. (II-2B) LABOUR MANAGEMENT: 4. Clinical pelvic examination should be performed to rule out pathological pelvic contraction. Radiologic pelvimetry is not necessary for a safe trial of labour; good progress in labour is the best indicator of adequate fetal-pelvic proportions. (III-B) 5. Continuous electronic fetal heart monitoring is preferable in the first stage and mandatory in the second stage of labour. (I-A) When membranes rupture, immediate vaginal examination is recommended to rule out prolapsed cord. (III-B) 6. In the absence of adequate progress in labour, Caesarean section is advised. (II-1A) 7. Induction of labour is not recommended for breech presentation. (II-3B) Oxytocin augmentation is acceptable in the presence of uterine dystocia. (II-1A) 8. A passive second stage without active pushing may last up to 90 minutes, allowing the breech to descend well into the pelvis. Once active pushing commences, if delivery is not imminent after 60 minutes, Caesarean section is recommended. (I-A) 9. The active second stage of labour should take place in or near an operating room with equipment and personnel available to perform a timely Caesarean section if necessary. (III-A) 10. A health care professional skilled in neonatal resuscitation should be in attendance at the time of delivery. (III-A) DELIVERY TECHNIQUE: 11. The health care provider for a planned vaginal breech delivery needs to possess the requisite skills and experience. (II-1A) 12. An experienced obstetrician-gynaecologist comfortable in the performance of vaginal breech delivery should be present at the delivery to supervise other health care providers, including a trainee. (I-A) 13. The requirements for emergency Caesarean section, including availability of the hospital operating room team and the approximate 30-minute timeline to commence a laparotomy, must be in accordance with the recommendations of the SOGC Policy Statement, "Attendance at Labour and Delivery" (CPG No. 89; update in press, 2009). (III-A) 14. The health care provider should have rehearsed a plan of action and should be prepared to act promptly in the rare circumstance of a trapped after-coming head or irreducible nuchal arms: symphysiotomy or emergency abdominal rescue can be life saving. (III-B) 15. Total breech extraction is inappropriate for term singleton breech delivery. (II-2A) 16. Effective maternal pushing efforts are essential to safe delivery and should be encouraged. (II-1A) 17. At the time of delivery of the after-coming head, an assistant should be present to apply suprapubic pressure to favour flexion and engagement of the fetal head. (II-3B) 18. Spontaneous or assisted breech delivery is acceptable. Fetal traction should be avoided, and fetal manipulation must be applied only after spontaneous delivery to the level of the umbilicus. (III-A) 19. Nuchal arms may be reduced by the Løvset or Bickenbach manoeuvres. (III-B) 20. The fetal head may deliver spontaneously, with the assistance of suprapubic pressure, by Mauriceau-Smellie-Veit manoeuvre, or with the assistance of Piper forceps. (III-B) SETTING AND CONSENT: 21. In the absence of a contraindication to vaginal delivery, a woman with a breech presentation should be informed of the risks and benefits of a trial of labour and elective Caesarean section, and informed consent should be obtained. A woman's choice of delivery mode should be respected. (III-A) 22. The consent discussion and chosen plan should be well documented and communicated to labour-room staff. (III-B) 23. Hospitals offering a trial of labour should have a written protocol for eligibility and intrapartum management. (III-B) 24. Women with a contraindication to a trial of labour should be advised to have a Caesarean section. Women choosing to labour despite this recommendation have a right to do so and should not be abandoned. They should be provided the best possible in-hospital care. (III-A) 25. The Society of Obstetricians and Gynaecologists of Canada (SOGC), in collaboration with the Association of Professors of Obstetrics and Gynaecology (APOG), The College of Family Physicians of Canada (CFPC), and The Canadian Association of Midwives (CAM) should revise the training requirements at the undergraduate and postgraduate levels. SOGC will continue to promote training of current health care providers through the MOREOB, ALARM (Advances in Labour and Risk Management), and other courses. (III-A) 26. Theoretical and hands-on breech birth training simulation should be part of basic obstetrical skills training programs such as ALARM, ALSO (Advanced Life Support Training in Obstetrics), and MOREOB to prepare health care providers for unexpected vaginal breech births. (III-B).