Lynda Hudon

Obesity in Pregnancy

OBJECTIVE To review the evidence and provide recommendations for the counselling and management of obese parturients. OUTCOMES Outcomes evaluated include the impact of maternal obesity on the provision of antenatal and intrapartum care, maternal morbidity and mortality, and perinatal morbidity and mortality. EVIDENCE Literature was retrieved through searches of Statistics Canada, Medline, and The Cochrane Library on the impact of obesity in pregnancy on antepartum and intrapartum care, maternal morbidity and mortality, obstetrical anaesthesia, and perinatal morbidity and mortality. Results were restricted to systematic reviews, randomized controlled 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 April 2009. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice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 The evidence obtained was reviewed and evaluated by the Maternal Fetal Medicine and Clinical Practice Obstetric Committees of the SOGC under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS Implementation of the recommendations in this guideline should increase recognition of the issues clinicians need to be aware of when managing obese women in pregnancy, improve communication and consultation amongst the obstetrical care team, and encourage federal and provincial agencies to educate Canadians about the values of entering pregnancy with as healthy a weight as possible. RECOMMENDATIONS 1. Periodic health examinations and other appointments for gynaecologic care prior to pregnancy offer ideal opportunities to raise the issue of weight loss before conception. Women should be encouraged to enter pregnancy with a BMI < 30 kg/m(2), and ideally < 25 kg/m(2). (III-B). 2. BMI should be calculated from pre-pregnancy height and weight. Those with a pre-pregnancy BMI > 30 kg/m(2) are considered obese. This information can be helpful in counselling women about pregnancy risks associated with obesity. (II-2B). 3. Obese pregnant women should receive counselling about weight gain, nutrition, and food choices. (II-2B). 4. Obese women should be advised that they are at risk for medical complications such as cardiac disease, pulmonary disease, gestational hypertension, gestational diabetes, and obstructive sleep apnea. Regular exercise during pregnancy may help to reduce some of these risks. (II-2B). 5. Obese women should be advised that their fetus is at an increased risk of congenital abnormalities, and appropriate screening should be done. (II-2B). 6. Obstetric care providers should take BMI into consideration when arranging for fetal anatomic assessment in the second trimester. Anatomic assessment at 20 to 22 weeks may be a better choice for the obese pregnant patient. (II-2B). 7. Obese pregnant women have an increased risk of Caesarean section, and the success of vaginal birth after Caesarean section is decreased. (II-2B). 8. Antenatal consultation with an anaesthesiologist should be considered to review analgesic options and to ensure a plan is in place should a regional anaesthetic be chosen. (III-B). 9. The risk of venous thromboembolism for each obese woman should be evaluated. In some clinical situations, consideration for thromboprophylaxis should be individualized. (III-B).

Substance Use in Pregnancy

OBJECTIVE To improve awareness and knowledge of problematic substance use in pregnancy and to provide evidence-based recommendations for the management of this challenging clinical issue for all health care providers. OPTIONS This guideline reviews the use of screening tools, general approach to care, and recommendations for clinical management of problematic substance use in pregnancy. OUTCOMES Evidence-based recommendations for screening and management of problematic substance use during pregnancy and lactation. EVIDENCE Medline, PubMed, CINAHL, and The Cochrane Library were searched for articles published from 1950 using the following key words: substance-related disorders, mass screening, pregnancy complications, pregnancy, prenatal care, cocaine, cannabis, methadone, opioid, tobacco, nicotine, solvents, hallucinogens, and amphetamines. Results were initially restricted to systematic reviews and randomized control trials/controlled clinical trials. A subsequent search for observational studies was also conducted because there are few RCTs in this field of study. Articles were restricted to human studies published in English. Additional articles were located by hand searching through article reference lists. Searches were updated on a regular basis and incorporated in the guideline up to December 2009. Grey (unpublished) literature was also 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 The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on the Preventive Health Care. Recommendations for practice were ranked according to the method described in that report (Table 1). BENEFITS, HARMS, AND COSTS This guideline is intended to increase the knowledge and comfort level of health care providers caring for pregnant women who have substance use disorders. Improved access to health care and assistance with appropriate addiction care leads to reduced health care costs and decreased maternal and neonatal morbidity and mortality. RECOMMENDATIONS 1. All pregnant women and women of childbearing age should be screened periodically for alcohol, tobacco, and prescription and illicit drug use. (III-A) 2. When testing for substance use is clinically indicated, urine drug screening is the preferred method. (II-2A) Informed consent should be obtained from the woman before maternal drug toxicology testing is ordered. (III-B) 3. Policies and legal requirements with respect to drug testing of newborns may vary by jurisdiction, and caregivers should be familiar with the regulations in their region. (III-A) 4. Health care providers should employ a flexible approach to the care of women who have substance use problems, and they should encourage the use of all available community resources. (II-2B) 5. Women should be counselled about the risks of periconception, antepartum, and postpartum drug use. (III-B) 6. Smoking cessation counselling should be considered as a first-line intervention for pregnant smokers. (I-A) Nicotine replacement therapy and/or pharmacotherapy can be considered if counselling is not successful. (I-A) 7. Methadone maintenance treatment should be standard of care for opioid-dependent women during pregnancy. (II-IA) Other slow-release opioid preparations may be considered if methadone is not available. (II-2B) 8. Opioid detoxification should be reserved for selected women because of the high risk of relapse to opioids. (II-2B) 9. Opiate-dependent women should be informed that neonates exposed to heroin, prescription opioids, methadone, or buprenorphine during pregnancy are monitored closely for symptoms and signs of neonatal withdrawal (neonatal abstinence syndrome). (II-2B) Hospitals providing obstetric care should develop a protocol for assessment and management of neonates exposed to opiates during pregnancy. (III-B) 10. Antenatal planning for intrapartum and postpartum analgesia may be offered for all women in consultation with appropriate health care providers. (III-B) 11. The risks and benefits of breastfeeding should be weighed on an individual basis because methadone maintenance therapy is not a contraindication to breastfeeding. (II-3B).

Intrauterine Growth Restriction: Screening, Diagnosis, and Management

BACKGROUND Intrauterine growth restriction (IUGR) is an obstetrical complication, which by definition would screen in 10% of fetuses in the general population. The challenge is to identify the subset of pregnancies affected with pathological growth restriction in order to allow intervention that would decrease morbidity and mortality. OBJECTIVE The purpose of this guideline is to provide summary statements and recommendations and to establish a framework for screening, diagnosis, and management of pregnancies affected with IUGR. METHODS Affected pregnancies are compared with pregnancies in which the fetus is at an appropriate weight for its gestational age. History, physical examination, and laboratory investigations including biochemical markers and ultrasound characteristics of IUGR are reviewed, and a management strategy is suggested. EVIDENCE Published literature in English was retrieved through searches of PubMed or MEDLINE, CINAHL, and The Cochrane Library in January 2013 using appropriate controlled vocabulary via MeSH terms (fetal growth restriction and small for gestational age) and key words (fetal growth, restriction, growth retardation, IUGR, low birth weight, small for gestational age). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. 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). BENEFITS, HARMS, AND COSTS Implementation of the recommendations in this guideline should increase clinician recognition of IUGR and guide intervention where appropriate. Optimal long-term follow-up of neonates diagnosed as IUGR may improve their long-term health.

Cytomegalovirus Infection in Pregnancy

OBJECTIVES To review the principles of prenatal diagnosis of congenital cytomegalovirus (CMV) infection and to describe the outcomes of the affected pregnancies. OUTCOMES Effective management of fetal infection following primary and secondary maternal CMV infection during pregnancy. Neonatal signs include intrauterine growth restriction (IUGR), microcephaly, hepatosplenomegaly, petechiae, jaundice, chorioretinitis, thrombocytopenia and anemia, and long-term sequelae consist of sensorineural hearing loss, mental retardation, delay of psychomotor development, and visual impairment. These guidelines provide a framework for diagnosis and management of suspected CMV infections. EVIDENCE Medline was searched for articles published in English from 1966 to 2009, using appropriate controlled vocabulary (congenital CMV infection) and key words (intrauterine growth restriction, microcephaly). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline. 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. RECOMMENDATIONS The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1). 1. Diagnosis of primary maternal cytomegalovirus (CMV) infection in pregnancy should be based on de-novo appearance of virus-specific IgG in the serum of a pregnant woman who was previously seronegative, or on detection of specific IgM antibody associated with low IgG avidity. (II-2A) 2. In case of primary maternal infection, parents should be informed about a 30% to 40% risk for intrauterine transmission and fetal infection, and a risk of 20% to 25% for development of sequelae postnatally if the fetus is infected. (II-2A) 3. The prenatal diagnosis of fetal CMV infection should be based on amniocentesis, which should be done at least 7 weeks after presumed time of maternal infection and after 21 weeks of gestation. This interval is important because it takes 5 to 7 weeks following fetal infection and subsequent replication of the virus in the kidney for a detectable quantity of the virus to be secreted to the amniotic fluid. (II-2A) 4. The diagnosis of secondary infection should be based on a significant rise of IgG antibody titre with or without the presence of IgM and high IgG avidity. In cases of proven secondary infection, amniocentesis may be considered, but the risk-benefit ratio is different because of the low transmission rate. (III-C) 5. Following a diagnosis of fetal CMV infection, serial ultrasound examinations should be performed every 2 to 4 weeks to detect sonographic abnormalities, which may aid in determining the prognosis of the fetus, although it is important to be aware that the absence of sonographic findings does not guarantee a normal outcome. (II-2B) 6. Quantitative determination of CMV DNA in the amniotic fluid may assist in predicting the fetal outcome. (II-3B) 7. Routine screening of pregnant women for CMV by serology testing is currently not recommended. (III-B) 8. Serologic testing for CMV may be considered for women who develop influenza-like illness during pregnancy or following detection of sonographic findings suggestive of CMV infection. (III-B) 9. Seronegative health care and child care workers may be offered serologic monitoring during pregnancy. Monitoring may also be considered for seronegative pregnant women who have a young child in day care. (III-B).

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.

Ultrasonographic Cervical Length Assessment in Predicting Preterm Birth in Singleton Pregnancies

OBJECTIVES To review (1) the use of ultrasonographic-derived cervical length measurement in predicting preterm birth and (2) interventions associated with a short cervical length. OUTCOMES Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions. EVIDENCE Published literature was retrieved through searches of PubMed and The Cochrane Library up to December 2009, using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, incompetent cervix, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. 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 The evidence and this guideline were reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made according to the guidelines developed by The Canadian Task Force on Preventive Health Care (Table 1). BENEFITS, HARMS, AND COSTS Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the ultrasonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth. SPONSORS The Society of Obstetricians and Gynaecologists of Canada.

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).

Management of Varicella Infection (Chickenpox) in Pregnancy

OBJECTIVE To review the existing data regarding varicella zoster virus infection (chickenpox) in pregnancy, interventions to reduce maternal complications and fetal infection, and antepartum and peripartum management. METHODS The maternal and fetal outcomes in varicella zoster infection were reviewed, as well as the benefit of the different treatment modalities in altering maternal and fetal sequelae. EVIDENCE Medline was searched for articles and clinical guidelines published in English between January 1970 and November 2010. VALUES The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. Recommendations for practice were ranked according to the method described in that report (Table). RECOMMENDATIONS 1. Varicella immunization is recommended for all non-immune women as part of pre-pregnancy and postpartum care. (II-3B) 2. Varicella vaccination should not be administered in pregnancy. However, termination of pregnancy should not be advised because of inadvertent vaccination during pregnancy. (II-3D) 3. The antenatal varicella immunity status of all pregnant women should be documented by history of previous infection, varicella vaccination, or varicella zoster immunoglobulin G serology. (III-C) 4. All non-immune pregnant women should be informed of the risk of varicella infection to themselves and their fetuses. They should be instructed to seek medical help following any contact with a person who may have been contagious. (II-3B) 5. In the case of a possible exposure to varicella in a pregnant woman with unknown immune status, serum testing should be performed. If the serum results are negative or unavailable within 96 hours from exposure, varicella zoster immunoglobulin should be administered. (III-C) 6. Women who develop varicella infection in pregnancy need to be made aware of the potential adverse maternal and fetal sequelae, the risk of transmission to the fetus, and the options available for prenatal diagnosis. (II-3C) 7. Detailed ultrasound and appropriate follow-up is recommended for all women who develop varicella in pregnancy to screen for fetal consequences of infection. (III-B) 8. Women with significant (e.g., pneumonitis) varicella infection in pregnancy should be treated with oral antiviral agents (e.g., acyclovir 800 mg 5 times daily). In cases of progression to varicella pneumonitis, maternal admission to hospital should be seriously considered. Intravenous acyclovir can be considered for severe complications in pregnancy (oral forms have poor bioavailability). The dose is usually 10 to 15 mg/kg of BW or 500 mg/m² IV every 8 h for 5 to 10 days for varicella pneumonitis, and it should be started within 24 to 72 h of the onset of rash. (III-C) 9. Neonatal health care providers should be informed of peripartum varicella exposure in order to optimize early neonatal care with varicella zoster immunoglobulin and immunization. (III-C) Varicella zoster immunoglobulin should be administered to neonates whenever the onset of maternal disease is between 5 days before and 2 days after delivery. (III-C).

Classification of Caesarean Sections in Canada: The Modified Robson Criteria

OBJECTIVE To advocate for the use of a common classification system for Caesarean section across Canada. OPTIONS A variety of clinical parameters for classification were considered. OUTCOMES Consideration of a common system for classifying Caesarean section. EVIDENCE Studies published in English from 1976 to December 2011 were retrieved through searches of Medline and PubMed, using appropriate controlled vocabulary and key words (Caesarean section, vaginal birth after Caesarean, classification). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Grey (unpublished) literature was identified through searching the web sites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and the web sites of national and international medical specialty societies. VALUES The studies reviewed were classified according to criteria described by the Canadian Task Force on Preventive Health Care, and the recommendation for practice ranked according to this classification (Table 1). SPONSORS The Society of Obstetricians and Gynaecologists of Canada. Recommendation Modified Robson criteria should be used to enable comparison of Caesarean section rates and indications. (III-B).