Kirsten Grabowska

Vaginal delivery of breech presentation

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.

The Use of Progesterone for Prevention of Preterm Birth

OBJECTIVE To introduce new information on the use of progesterone to prevent premature labour and to provide guidance to obstetrical caregivers who counsel women on the merits of this choice OPTIONS This discussion is limited to progesterone therapy for prevention of preterm labour (PTL) in women at increased risk of PTL. EVIDENCE A search of both Medline and the Cochrane Library identified the most relevant medical evidence. This document represents an abstraction of the evidence rather than a methodological review. The level of evidence and quality of recommendations are described using the criteria and classifications of the Canadian Task Force on Preventive Health Care (Table 1). VALUES This update is the consensus of the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC). BENEFITS, HARMS, AND COSTS Counselling the patient at increased risk for PTL should include consideration of the potential benefits of progesterone use and our lack of/limited knowledge of many neonatal outcomes and optimal dosing.

Guidelines for the Management of Vasa Previa

OBJECTIVES To describe the etiology of vasa previa and the risk factors and associated condition, to identify the various clinical presentations of vasa previa, to describe the ultrasound tools used in its diagnosis, and to describe the management of vasa previa. OUTCOMES Reduction of perinatal mortality, short-term neonatal morbidity, long-term infant morbidity, and short-term and long-term maternal morbidity and mortality. EVIDENCE Published literature on randomized trials, prospective cohort studies, and selected retrospective cohort studies was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library, using appropriate controlled vocabulary (e.g., selected epidemiological studies comparing delivery by Caesarean section with vaginal delivery; studies comparing outcomes when vasa previa is diagnosed antenatally vs. intrapartum) and key words (e.g., vasa previa). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline to October 1, 2008. 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 from national and international medical specialty societies. VALUES The evidence collected was reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS The benefit expected from this guideline is facilitation of optimal and uniform care for pregnancies complicated by vasa previa. SPONSORS The Society of Obstetricians and Gynaecologists of Canada. SUMMARY STATEMENT A comparison of women who were diagnosed antenatally and those who were not shows respective neonatal survival rates of 97% and 44%, and neonatal blood transfusion rates of 3.4% and 58.5%, respectively. Vasa previa can be diagnosed antenatally, using combined abdominal and transvaginal ultrasound and colour flow mapping; however, many cases are not diagnosed, and not making such a diagnosis is still acceptable. Even under the best circumstances the false positive rate is extremely low. (II-2). RECOMMENDATIONS 1. If the placenta is found to be low lying at the routine second trimester ultrasound examination, further evaluation for placental cord insertion should be performed. (II-2B) 2. Transvaginal ultrasound may be considered for all women at high risk for vasa previa, including those with low or velamentous insertion of the cord, bilobate or succenturiate placenta, or for those having vaginal bleeding, in order to evaluate the internal cervical os. (II-2B) 3. If vasa previa is suspected, transvaginal ultrasound colour Doppler may be used to facilitate the diagnosis. Even with the use of transvaginal ultrasound colour Doppler, vasa previa may be missed. (II-2B) 4. When vasa previa is diagnosed antenatally, an elective Caesarean section should be offered prior to the onset of labour. (II-1A) 5. In cases of vasa previa, premature delivery is most likely; therefore, consideration should be given to administration of corticosteroids at 28 to 32 weeks to promote fetal lung maturation and to hospitalization at about 30 to 32 weeks. (II-2B) 6. In a woman with an antenatal diagnosis of vasa previa, when there has been bleeding or premature rupture of membranes, the woman should be offered delivery in a birthing unit with continuous electronic fetal heart rate monitoring and, if time permits, a rapid biochemical test for fetal hemoglobin, to be done as soon as possible; if any of the above tests are abnormal, an urgent Caesarean section should be performed. (III-B) 7. Women admitted with diagnosed vasa previa should ideally be transferred for delivery in a tertiary facility where a pediatrician and blood for neonatal transfusion are immediately available in case aggressive resuscitation of the neonate is necessary. (II-3B) 8. Women admitted to a tertiary care unit with a diagnosis of vasa previa should have this diagnosis clearly identified on the chart, and all health care providers should be made aware of the potential need for immediate delivery by Caesarean section if vaginal bleeding occurs. (III-B).

Delivery by Caesarean Section in Super-Obese Women: Beyond Pfannenstiel

J Obstet Gynaecol Can 2012;34(5):472–474 P in women who are super-obese, defined by body mass index over 50 kg/m2, has risen relentlessly across North America during the past decade. Currently 2% of deliveries are affected by super-obesity in parts of the southern United States, where young women of AfricanAmerican and Hispanic descent constitute the fastest growing segments of the population.1 In Canada, obstetricians are caring for increasing numbers of very overweight women from a variety of backgrounds. All obstetricians providing labour and delivery services to such women need to be prepared for delivery by Caesarean section (CS) because of the surgical challenges, especially since the risk of having to perform CS in labour may exceed 50%.2 Elective CS, often performed because of suspected macrosomia, may best serve many women in this BMI category. Increasingly such women are concentrated in focused antenatal clinics where preoperative discussions lead to elective daytime surgery performed by experienced personnel. Nevertheless, superobese women do begin labour spontaneously or may have labour induced, and thus the on-call labour and delivery obstetrician will face significant delivery challenges. What advice is available to assist on-call staff when performing CS in these women? Current editions of two leading textbooks offer no guidance on the approach to CS in super-obese women.3,4 By contrast, the online resource tool “UpToDate” devotes a section to this subject5 with the following advice: first, while elevation of the pannus may permit access to the abdomen through a traditional Pfannenstiel incision, the risk of wound infection may be reduced by weight-adjusted prophylactic pre-incision administration of intravenous antibiotics, minimal fat layer disturbance on entry, and closure of this layer on exit with skin staples to permit seroma drainage. This resource warns that postoperative wound complications should be anticipated in up to 25% of these patients and that the patients may require extended follow-up after initial discharge because the presentation is often delayed. If technically possible, a Pfannenstiel incision for entry beneath the pannus has important benefits, provided the surgeon can anticipate having easy access to a presenting fetal pole in the lower uterine segment. The skin incision should ideally be placed in healthy skin at least 2 cm above the natural crease. Modest use of the Trendelenberg position helps to keep the plane of surgery horizontal. Insertion of a self-retaining Mobius retractor (CooperSurgical, Inc., Trumbull CT), followed by lateral abdominal wet packs, gives optimal exposure and allows the operation to proceed with only one assistant. Before the surgery, the surgeon should become familiar with interior ring insertion and exterior ring rolling to maximize exposure.6 The uterus is closed in situ with this approach.