Philip Wyatt

Association of neural tube defects and folic acid food fortification in Canada

Many women do not receive folic acid supplements before conception. In response, most of Canadas cereal grain products were being fortified with folic acid by January, 1998, thereby providing an additional 0.1-0.2 mg per day of dietary folate to the Canadian population. We assessed the effect of supplementation on prevalence of open neural tube defects in the province of Ontario. Among 336 963 women who underwent maternal serum screening over 77 months, the prevalence of open neural tube defects declined from 1.13 per 1000 pregnancies before fortification to 0.58 per 1000 pregnancies thereafter (prevalence ratio 0.52, 95% CI 0.40-0.67, p<0.0001). At a population level, folic acid food fortification is associated with a pronounced reduction in open neural tube defects.

Pre-conceptional Vitamin/Folic Acid Supplementation 2007: The Use of Folic Acid in Combination With a Multivitamin Supplement for the Prevention of Neural Tube Defects and Other Congenital Anomalies

OBJECTIVE To provide information regarding the use of folic acid in combination with a multivitamin supplement for the prevention of neural tube defects and other congenital anomalies, so that physicians, midwives, nurses, and other health care workers can assist in the education of women in the pre-conception phase of their health care. OPTION: Supplementation with folic acid and vitamins is problematic, since 50% of pregnancies are unplanned, and womens health status may not be optimal when they conceive. OUTCOMES Folic acid in combination with a multivitamin supplement has been associated with a decrease in specific birth defects. EVIDENCE Medline, PubMed, and Cochrane Database were searched for relevant English language articles published between 1985 and 2007. The previous Society of Obstetricians and Gynaecologists of Canada (SOGC) Policy Statement of November 1993 and statements from the American College of Obstetrics and Gynecology and Canadian College of Medical Geneticists were also reviewed in developing this clinical practice guideline. VALUES The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS Promoting the use of folic acid and a multivitamin supplement among women of reproductive age will reduce the incidence of birth defects. The costs are those of daily vitamin supplementation and eating a healthy diet. RECOMMENDATIONS 1. Women in the reproductive age group should be advised about the benefits of folic acid in addition to a multivitamin supplement during wellness visits (birth control renewal, Pap testing, yearly examination) especially if pregnancy is contemplated. (III-A) 2. Women should be advised to maintain a healthy diet, as recommended in Eating Well With Canadas Food Guide (Health Canada). Foods containing excellent to good sources of folic acid are fortified grains, spinach, lentils, chick peas, asparagus, broccoli, peas, Brussels sprouts, corn, and oranges. However, it is unlikely that diet alone can provide levels similar to folate-multivitamin supplementation. (III-A) 3. Women taking a multivitamin containing folic acid should be advised not to take more than one daily dose of vitamin supplement, as indicated on the product label. (II-2-A) 4. Folic acid and multivitamin supplements should be widely available without financial or other barriers for women planning pregnancy to ensure the extra level of supplementation. (III-B) 5. Folic acid 5 mg supplementation will not mask vitamin B12 deficiency (pernicious anemia), and investigations (examination or laboratory) are not required prior to initiating supplementation. (II-2-A) 6. The recommended strategy to prevent recurrence of a congenital anomaly (anencephaly, myelomeningocele, meningocele, oral facial cleft, structural heart disease, limb defect, urinary tract anomaly, hydrocephalus) that has been reported to have a decreased incidence following preconception / first trimester folic acid +/- multivitamin oral supplementation is planned pregnancy +/- supplementation compliance. A folate-supplemented diet with additional daily supplementation of multivitamins with 5 mg folic acid should begin at least three months before conception and continue until 10 to 12 weeks post conception. From 12 weeks post-conception and continuing throughout pregnancy and the postpartum period (4-6 weeks or as long as breastfeeding continues), supplementation should consist of a multivitamin with folic acid (0.4-1.0 mg). (I-A) 7. The recommended strategy(ies) for primary prevention or to decrease the incidence of fetal congenital anomalies will include a number of options or treatment approaches depending on patient age, ethnicity, compliance, and genetic congenital anomaly risk status. OPTION A: Patients with no personal health risks, planned pregnancy, and good compliance require a good diet of folate-rich foods and daily supplementation with a multivitamin with folic acid (0.4-1.0 mg) for at least two to three months before conception and throughout pregnancy and the postpartum period (4-6 weeks and as long as breastfeeding continues). (II-2-A) OPTION B: Patients with health risks, including epilepsy, insulin dependent diabetes, obesity with BMI >35 kg/m2, family history of neural tube defect, belonging to a high-risk ethnic group (e.g., Sikh) require increased dietary intake of folate-rich foods and daily supplementation, with multivitamins with 5 mg folic acid, beginning at least three months before conception and continuing until 10 to 12 weeks post conception. From 12 weeks post-conception and continuing throughout pregnancy and the postpartum period (4-6 weeks or as long as breastfeeding continues), supplementation should consist of a multivitamin with folic acid (0.4-1.0 mg). (II-2-A) OPTION C: Patients who have a history of poor compliance with medications and additional lifestyle issues of variable diet, no consistent birth control, and possible teratogenic substance use (alcohol, tobacco, recreational non-prescription drugs) require counselling about the prevention of birth defects and health problems with folic acid and multivitamin supplementation. The higher dose folic acid strategy (5 mg) with multivitamin should be used, as it may obtain a more adequate serum red blood cell folate level with irregular vitamin / folic acid intake but with a minimal additional health risk. (III-B) 8. The Canadian Federal Government could consider an evaluation process for the benefit/risk of increasing the level of national folic acid flour fortification to 300 mg/100 g (present level 140 mg/100 g). (III-B) 9. The Canadian Federal Government could consider an evaluation process for the benefit/risk of additional flour fortification with multivitamins other than folic acid. (III-B) 10. The Society of Obstetricians and Gynaecologists of Canada will explore the possibility of a Canadian Consensus conference on the use of folic acid and multivitamins for the primary prevention of specific congenital anomalies. The conference would include Health Canada/Congenital Anomalies Surveillance, Canadian College of Medical Geneticists, Canadian Paediatric Society, Motherisk, and pharmaceutical industry representatives. VALIDATION This is a revision of a previous guideline and information from other consensus reviews from medical and government publications has been used. SPONSOR The Society of Obstetricians and Gynaecologists of Canada.

Pregnancy Outcomes After Assisted Reproductive Technology

OBJECTIVE To review the effect of assisted reproductive technology (ART) on perinatal outcomes, to provide guidelines to optimize obstetrical management and counselling of Canadian women using ART, and to identify areas specific to birth outcomes and ART requiring further research. OPTIONS Perinatal outcomes of ART pregnancies in subfertile women are compared with those of spontaneously conceived pregnancies. Perinatal outcomes are compared between different types of ART. OUTCOMES This guideline discusses the adverse outcomes that have been recorded in association with ART, including obstetrical complications, adverse perinatal outcomes, multiple gestations, structural congenital abnormalities, chromosomal abnormalities, imprinting disorders, and childhood cancer. EVIDENCE The Cochrane Library and MEDLINE were searched for English-language articles from 1990 to February 2005, relating to assisted reproduction and perinatal outcomes. Search terms included assisted reproduction, assisted reproductive technology, ovulation induction, intracytoplasmic sperm injection (ICSI), embryo transfer, and in vitro fertilization (IVF). Additional publications were identified from the bibliographies of these articles as well as the Science Citation Index. Studies assessing gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) were excluded since they are rarely used in Canada. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key studies and supporting data for each recommendation are summarized with evaluative comments and referenced. VALUES The evidence collected was reviewed by the Genetics Committee and the Reproductive Endocrinology Infertility 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 the Periodic Health Examination. BENEFITS, HARMS, AND COSTS The type and magnitude of benefits, harms, and costs expected for patients from guideline implementation. This guideline has been reviewed by the Genetics Committee and the Reproductive Endocrinology and Infertility Committee, and approved by the Executive and Council of the Society of Obstetricians and Gynaecologists of Canada and the Board of the Canadian Fertility and Andrology Society. RECOMMENDATIONS 1. Spontaneous pregnancies in untreated infertile women may be at higher risk for obstetrical complications and perinatal mortality than spontaneous pregnancies in fertile women. Further research is required to clarify the contribution of infertility itself to adverse obstetrical and perinatal outcomes. (II-2A) 2. All men with severe oligozoospermia or azoospermia should be offered genetic/clinical counselling for informed consent and offered karyotyping for chromosomal abnormalities before attempting IVF-ICSI. They should be made aware of the availability of tests for Y chromosome microdeletion. Some patients may consider the option of donor insemination. (II-3B) 3. Couples exploring IVF-ICSI when the man has obstructive azoospermia should be offered genetic/clinical counselling for informed consent and offered genetic testing for alterations in genes associated with cystic fibrosis (CF) before attempting IVF-ICSI. (II-2A) 4. Pregnancies achieved by ovarian stimulation with gonadotropins and intrauterine insemination are at higher risk for perinatal complications, and close surveillance during pregnancy should be considered. It remains unclear if these increased risks are attributable to the underlying infertility, characteristics of the infertile couple, or use of assisted reproductive techniques. Multiple gestations remain a significant risk of gonadotropin treatment. (II-2A) 5. Pregnancies achieved by IVF with or without ICSI are at higher risk for obstetrical and perinatal complications than spontaneous pregnancies, and close surveillance during pregnancy should be considered. It remains unclear if these increased risks are attributable to the underlying infertility, characteristics of the infertile couple, or use of assisted reproductive techniques. (II-2A) 6. Women undergoing ART should be informed about the increased rate of obstetrical interventions such as induced labour and elective Caesarean delivery. (II-2A) 7. Couples suffering from infertility who are exploring treatment options should be made aware of the psychosocial implications of ART. Further research into the psychosocial impact of ART is needed. (II-2A) 8. Singleton pregnancies achieved by assisted reproduction are at higher risk than spontaneous pregnancies for adverse perinatal outcomes, including perinatal mortality, preterm delivery, and low birth weight, and close surveillance during pregnancy should be available as needed. (II-2A) 9. A significant risk of ART is multiple pregnancies. Infertile couples need to be informed of the increased risks of multifetal pregnancies. Although dichorionic twins are most common, the incidence of monochorionic twins is also increased. Risks of multiple pregnancies include higher rates of perinatal mortality, preterm birth, low birth weight, gestational hypertension, placental abruption, and placenta previa. Perinatal mortality in assisted conception twin pregnancies appears to be lower than in spontaneously conceived twin pregnancies. (II-2A) 10. When multifetal reduction is being considered for high-order multiple pregnancies, psychosocial counselling should be readily available. Careful surveillance for fetal growth problems should be undertaken after multifetal reduction. (II-2A) 11. To reduce the risks of multiple pregnancies associated with ART and to optimize pregnancy rates, national guidelines should be developed on the number of embryos replaced according to characteristics such as patients age and grade of embryos. (II-2A) 12. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks to childhood and long-term growth and development associated with ART. (II-2A) 13. Discussion of options for prenatal screening for congenital structural abnormalities in pregnancies achieved by ART is recommended, including appropriate use of biochemical and sonographic screening. (II-2A) 14. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks of congenital abnormalities associated with ART. (II-2A) 15. Couples considering IVF-ICSI for male-factor infertility should receive information, and if necessary formal genetic counselling, about the increased risk of de novo chromosomal abnormalities (mainly sex chromosomal anomalies) associated with their condition. Prenatal diagnosis by chorionic villus sampling (CVS) or amniocentesis should be offered to these couples if they conceive. (II-2A) 16. Further epidemiologic and basic science research is needed to help determine the etiology and extent of the increased risks of chromosomal abnormalities associated with ART. (II-2A) 17. Discussion of options for prenatal screening and testing for aneuploidy in pregnancies achieved by ART, adapted for maternal age and number of fetuses, is recommended, including appropriate use of biochemical and sonographic screening. (II-2A) 18. The precise risks of imprinting and childhood cancer from ART remain unclear but cannot be ignored. Further clinical research, including long-term follow-up, is urgently required to evaluate the prevalence of imprinting disorders and cancers associated with ART. (II-2A) 19. The clinical application of preimplantation genetic diagnosis must balance the benefits of avoiding disease transmission with the medical risks and financial burden of in vitro fertilization. Further ethical discussion and clinical research is required to evaluate appropriate indications for preimplantation genetic diagnosis. (III-B).

Obstetrical complications associated with abnormal maternal serum markers analytes.

OBJECTIVE To review the obstetrical outcomes associated with abnormally elevated or decreased level of one or more of the most frequently measured maternal serum marker analytes used in screening for aneuploidy. To provide guidance to facilitate the management of pregnancies that have abnormal levels of one of more markers and to assess the usefulness of these markers as a screening test. OPTIONS Perinatal outcomes associated with abnormal levels of maternal serum markers analytes are compared with the outcomes of pregnancies with normal levels of the same analytes or the general population. EVIDENCE The Cochrane Library and Medline were searched for English-language articles published from 1966 to February 2007, relating to maternal serum markers and perinatal outcomes. Search terms included PAPP-A (pregnancy associated plasma protein A), AFP (alphafetoprotein), hCG (human chorionic gonadotropin), estriol, unconjugated estriol, inhibin, inhibin-A, maternal serum screen, triple marker screen, quadruple screen, integrated prenatal screen, first trimester screen, and combined prenatal screen. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key individual studies on which the recommendations are based are referenced. Supporting data for each recommendation are summarized with evaluative comments and references. The evidence was evaluated using the guidelines developed by the Canadian Task Force on Preventive Health Care. VALUES The evidence collected was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada. BENEFITS, HARMS, AND COSTS The benefit expected from this guideline is to facilitate early detection of potential adverse pregnancy outcomes when risks are identified at the time of a maternal serum screen. It will help further stratification of risk and provide options for pregnancy management to minimize the impact of pregnancy complications. The potential harms resulting from such practice are associated with the so called false positive (i.e., uncomplicated pregnancies labelled at increased risk for adverse perinatal outcomes), the potential stress associated with such a label, and the investigations performed for surveillance in this situation. No cost-benefit analysis is available to assess costs and savings associated with this guideline. SUMMARY STATEMENTS: 1. An unexplained level of a maternal serum marker analyte is defined as an abnormal level after confirmation of gestational age by ultrasound and exclusion of maternal, fetal, or placental causes for the abnormal level. (III) 2. Abnormally elevated levels of serum markers are associated with adverse pregnancy outcomes in twin pregnancies, after correction for the number of fetuses. Spontaneous or planned mutifetal reductions may result in abnormal elevations of serum markers. (II-2) RECOMMENDATIONS: 1. In the first trimester, an unexplained low PAPP-A (< 0.4 MoM) and/or a low hCG (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) In the second trimester, an unexplained elevation of maternal serum AFP (> 2.5 MoM), hCG (> 3.0 MoM), and/or inhibin-A (> or =2.0 MoM) or a decreased level of maternal serum AFP (< 0.25 MoM) and/or unconjugated estriol (< 0.5 MoM) are associated with an increased frequency of adverse obstetrical outcomes, and, at present, no specific protocol for treatment is available. (II-2A) 2. Pregnant woman with an unexplained elevated PAPP-A or hCG in the first trimester and an unexplained low hCG or inhibin-A and an unexplained elevated unconjugated estriol in the second trimester should receive normal antenatal care, as this pattern of analytes is not associated with adverse perinatal outcomes. (II-2A) 3. The combination of second or third trimester placenta previa and an unexplained elevated maternal serum AFP should increase the index of suspicion for placenta accreta, increta, or percreta. (II-2B) An assessment (ultrasound, MRI) of the placental-uterine interface should be performed. Abnormal invasion should be strongly suspected, and the planning of delivery location and technique should be done accordingly. (III-C) 4. A prenatal consultation with the medical genetics department is recommended for low unconjugated estriol levels (<0.3 MoM), as this analyte pattern can be associated with genetic conditions. (II-2B) 5. The clinical management protocol for identification of potential adverse obstetrical outcomes should be guided by one or more abnormal maternal serum marker analyte value rather than the false positive screening results for the trisomy 21 and/or the trisomy 18 screen. (II-2B) 6. Pregnant woman who are undergoing renal dialysis or who have had a renal transplant should be offered maternal serum screening, but interpretation of the result is difficult as the level of serum hCG is not reliable. (II-2A) 7. Abnormal maternal uterine artery Doppler in association with elevated maternal serum AFP, hCG, or inhibin-A or decreased PAPP-A identifies a group of women at greater risk of IUGR and gestational hypertension with proteinuria. Uterine artery Doppler measurements may be used in the evaluation of an unexplained abnormal level of either of these markers. (II-2B) 8. Further research is recommended to identify the best protocol for pregnancy management and surveillance in women identified at increased risk of adverse pregnancy outcomes based on an abnormality of a maternal serum screening analyte. (III-A) 9. In the absence of evidence supporting any specific surveillance protocol, an obstetrician should be consulted in order to establish a fetal surveillance plan specific to the increased obstetrical risks (maternal and fetal) identified. This plan may include enhanced patient education on signs and symptoms of the most common complications, increased frequency of antenatal visits, increased ultrasound (fetal growth, amniotic fluid levels), and fetal surveillance (biophysical profile, arterial and venous Doppler), and cervical length assessment. (III-A) 10. Limited information suggests that, in women with elevated hCG in the second trimester and/or abnormal uterine artery Doppler (at 22-24 weeks), low-dose aspirin (60-81 mg daily) is associated with higher birthweight and lower incidence of gestational hypertension with proteinuria. This therapy may be used in women who are at risk. (II-2B) 11. Further studies are recommended in order to assess the benefits of low-dose aspirin, low molecular weight heparin, or other therapeutic options in pregnancies determined to be at increased risk on the basis of an abnormal maternal serum screening analyte. (III-A) 12. Multiple maternal serum markers screening should not be used at present as a population-based screening method for adverse pregnancy outcomes (such as preeclampsia, placental abruption, and stillbirth) outside an established research protocol, as sensitivity is low, false positive rates are high, and no management protocol has been shown to clearly improve outcomes. (II-2D) When maternal serum screening is performed for the usual clinical indication (fetal aneuploidy and/or neural tube defect), abnormal analyte results can be utilized for the identification of pregnancies at risk and to direct their clinical management. (II-2B) Further studies are recommended to determine the optimal screening method for poor maternal and/or perinatal outcomes. (III-A).

Vitamin B12 and the risk of neural tube defects in a folic-acid-fortified population.

Background: Low maternal vitamin B12 status may be a risk factor for neural tube defects (NTDs). Prior studies used relatively insensitive measures of B12, did not adjust for folate levels, and were conducted in countries without folic acid food fortification. In Canada, flour has been fortified with folic acid since mid-1997. Methods: We completed a population-based case–control study in Ontario. We measured serum holotranscobalamin (holoTC), a sensitive indicator of B12 status, at 15 to 20 weeks’ gestation. There were 89 women with an NTD and 422 unaffected pregnant controls. A low serum holoTC was defined as less than 55.3 pmol/L, the bottom quartile value in the controls. Results: The geometric mean serum holoTC levels were 67.8 pmol/L in cases and 81.2 pmol/L in controls. There was a trend of increasing risk with lower levels of holoTC, reaching an adjusted odds ratio of 2.9 (95% confidence interval = 1.2–6.9) when comparing the lowest versus highest quartile. Conclusions: There was almost a tripling in the risk for NTD in the presence of low maternal B12 status, measured by holoTC. The benefits of adding synthetic B12 to current recommendations for periconceptional folic acid tablet supplements or folic-acid-fortified foods need to be considered. It remains to be determined what fraction of NTD cases in a universally folate-fortified environment might be prevented by higher periconceptional intake of B12.

RARE TRISOMY MOSAICISM DIAGNOSED IN AMNIOCYTES, INVOLVING AN AUTOSOME OTHER THAN CHROMOSOMES 13, 18, 20, AND 21: KARYOTYPE/PHENOTYPE CORRELATIONS

In order to determine the significance of trisomy mosaicism of an autosome other than chromosomes 13, 18, 20, and 21, 151 such cases diagnosed prenatally through amniocentesis were reviewed. These rare trisomy mosaicism cases include 54 from 17 cytogenetic laboratories, 34 from a previous North American mosaicism survey, and 63 from published reports. All were cases of true mosaicism with information available on pregnancy outcome, and with no evidence of biased ascertainment. There were 11 cases of 46/47,+2; 2 of 46/47,+3; 2 of 46/47,+4; 5 of 46/47,+5; 3 of 46/47,+6; 8 of 46/47,+7; 14 of 46/47,+8; 25 of 46/47,+9; 2 of 46/47,+11; 23 of 46/47,+12; 5 of 46/47,+14; 11 of 46/47,+15; 21 of 46/47,+16; 7 of 46/47,+17; 1 of 46/47,+19; and 11 of 46/47,+22. As to the risk of an abnormal outcome, the data showed a very high risk (>60 per cent) for 46/47,+2, 46/47,+16, and 46/47,+22; a high risk (40–59 per cent) for 46/47,+5, 46/47,+9, 46/47,+14, and 46/47,+15; a moderately high risk (20–39 per cent) for 46/47,+12; a moderate risk (up to 19 per cent) for 46/47,+7 and 46/47,+8; a low risk for 46/47,+17; and an undetermined risk, due to lack of cases, for the remaining autosomal trisomy mosaics. Most cases were evaluated at birth or at termination, so subtle abnormalities may have escaped detection and developmental retardation was not evaluated at all. Comparison of the phenotypes of prenatally diagnosed abnormal cases and postnatally diagnosed cases with the same diagnosis showed considerable concordance. Since the majority of anomalies noted are prenatally detectable with ultrasound, an ultrasound examination should be performed in all prenatally diagnosed cases. In cytogenetic confirmation studies, the data showed much higher confirmation rates in cases with abnormal outcomes than in cases with normal outcomes [81 per cent vs. 55 per cent for fibroblasts (from skin, fetal tissue, and/or cord); 88 per cent vs. 46 per cent for placental cells; 22 per cent vs. 10 per cent for blood cells]. The confirmation rate reached 85 per cent when both fibroblasts and placental tissues were studied in the same case (with trisomic cells found in one or the other, or both). Therefore, one must emphasize that both fibroblasts and placental tissues should be studied. Except for 46/47,+8 and 46/47,+9, PUBS is of limited value for prenatal diagnosis of rare trisomy mosaicism. DNA studies for UPD are suggested for certain chromosomes with established imprinting effects, such as chromosomes 7, 11, 14, and 15, and perhaps for chromosomes 2 and 16, where imprinting effects are likely.

Greater maternal weight and the ongoing risk of neural tube defects after folic acid flour fortification.

OBJECTIVE: Maternal obesity is likely a risk factor for neural tube defects (NTDs). By late 1997, it became mandatory in Canada that all refined wheat flour be fortified with folic acid. Because overweight women may consume greater quantities of refined wheat flour, we questioned whether their risk of NTD changed after flour fortification. METHODS: A retrospective population-based study was conducted between 1994 and late 2000. We included all Ontarian women who underwent antenatal maternal screening at 15 to 20 weeks of gestation. Self-declared maternal date of birth, ethnicity, current weight, and the presence of pregestational diabetes mellitus were recorded in a standardized fashion on the maternal screening requisition sheet. The presence of NTDs was systematically detected both antenatally and postnatally. The risk of open NTD was evaluated across maternal weight quartiles and deciles, and an interaction between greater maternal weight and the presence of flour fortification was tested using multiple logistic regression analysis. RESULTS: A total of 292 open NTDs were detected among 420,362 women. The adjusted odds ratio (OR) for NTD was 1.2 (95% confidence interval [CI] 1.1–1.3) per 10-kg incremental rise in maternal weight. Comparing the highest with the lowest quartile of maternal weight, the adjusted OR for NTD was 2.6 (95% CI 1.8–4.0). A similar finding was observed for the highest compared with lowest weight deciles (adjusted OR 3.3, 95% CI 1.7–6.2). The interaction between elevated maternal weight and the presence of folic acid flour fortification was of borderline significance (P = .09). Before fortification, greater maternal weight was associated with a modestly increased risk of NTD (adjusted OR 1.4, 95% CI 1.0–1.8); after flour fortification, this effect was more pronounced (adjusted OR 2.8, 95% CI 1.2–6.6). CONCLUSION: These data emphasize the higher risk of NTD associated with increased maternal weight, even after universal folic acid flour fortification. Beyond periconceptional folic acid use, consideration should be given to testing whether prepregnancy weight reduction is an independent means of preventing NTD. LEVEL OF EVIDENCE: II-2

Teratogenicity Associated With Pre-Existing and Gestational Diabete

OBJECTIVE To review the teratogenesis associated with pre-existing and gestational diabetes, to provide guidelines to optimize prevention and diagnosis of fetal abnormalities in women with diabetes, and to identify areas specific to fetal abnormalities and diabetes requiring further research. OPTIONS Pre-conception counselling, pre-conception and first trimester folic acid supplementation, and glycemic control. OUTCOMES Increased awareness of fetal abnormalities associated with pre-existing and gestational diabetes. EVIDENCE The Cochrane Library and Medline were searched for English-language articles, published from 1990 to February 2005, relating to pre-existing and gestational diabetes and fetal abnormalities. Search terms included pregnancy, diabetes mellitus, pre-existing diabetes, type 1 diabetes, type 2 diabetes, insulin dependent diabetes, gestational diabetes, impaired glucose tolerance, congenital anomalies, malformations, and stillbirth. Additional publications were identified from the bibliographies of these articles as well as the Science Citation Index. All study types were reviewed. Randomized controlled trials were considered evidence of the highest quality, followed by cohort studies. Key studies and supporting data for each recommendation are summarized with evaluative comments and referenced. VALUES The evidence collected was reviewed by the Genetics and Maternal Fetal Medicine Committees 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. RECOMMENDATIONS 1. Experimental studies suggest that hyperglycemia is the major teratogen in diabetic pregnancies, but other diabetes-related factors may also affect fetal outcomes. Further research using animal models is required to clarify the teratogenic factors associated with pre-existing and gestational diabetes. (II-3C) 2. Prospective and retrospective cohort studies have demonstrated an increased risk of congenital abnormalities with pre-existing diabetes. Further studies that include outcomes from first and second trimester pregnancy terminations, account for potential confounding variables, and use appropriate control groups are required. (II-2A) 3. Prospective and retrospective cohort studies have demonstrated an increased risk of congenital abnormalities with gestational diabetes. This observation is probably related to the inclusion of women with unrecognized type 2 diabetes. Clarification of the relationship between gestational diabetes and congenital abnormalities by studies that include outcomes from first and second trimester pregnancy terminations, account for potential confounding variables, and use appropriate control groups are required. (II-2A) 4. In some women, type 2 diabetes may be identified for the first time in pregnancy. Pre-conception recognition of women at high risk for type 2 diabetes and optimal glycemic control may reduce the risk of congenital anomalies. (II-2A) 5. Second generation sulfonylureas have not been associated with congenital abnormalities in human studies. The use of biguanides may be associated with other adverse perinatal outcomes. The use of other oral antihyperglycemic agents is not recommended in pregnancy. (II-2A) 6. The risk of congenital anomalies is increased in the offspring of obese women with diabetes. A healthy diet and regular exercise may help optimize pre-pregnancy weight and reduce the risk of congenital anomalies. (II-2A) 7. Accurate determination of gestational age is required in women with diabetes. Given the increased risk of congenital abnormalities, they should be offered appropriate biochemical and ultrasonographic screening and a detailed evaluation of fetal cardiac structures. (II-2A) 8. Women with diabetes should be offered pre-conception counselling with a multidisciplinary team to optimize general health and glycemic control and to review the risks of congenital anomalies. (II-2A) 9. A careful history should be obtained to identify other factors, such as a positive family history or advanced maternal age, that may further increase the risk of congenital structural or chromosomal abnormalities. (II-2A) 10. Pregnancy in women with diabetes should be planned. Good contraceptive advice and pre-pregnancy counselling are essential. Euglycemia should be maintained before and during pregnancy. (II-2A) 11. All women with diabetes should be counselled regarding intake of foods high in folic acid, folate-fortified foods, and appropriate folic acid supplementation of 4 to 5 mg per day pre-conceptionally and in the first 12 weeks of gestation. (II-2A) 12. A substantial number of women with diabetes do not access pre-conception care programs. Strategies are needed to improve access to such programs and to maximize interventions associated with improved pregnancy outcomes, such as folic acid use. (II-2A) VALIDATION: These guidelines have been reviewed by the Genetics Committee and the Maternal Fetal Medicine Committee of the SOGC. Final approval has been given by the Executive and Council of the Society of Obstetricians and Gynaecologists of Canada.

Association between folic acid food fortification and congenital orofacial clefts

By January 1998, most of Canadas cereal grain products were being fortified with folic acid. Among 336963 women who underwent antenatal maternal serum screening, the prevalence of orofacial clefts did not change from before (1.15 per 1000) to after (1.21 per 1000) food fortification (prevalence ratio, 1.06; 95% confidence interval, 0.86-1.30).

Evaluation of Prenatally Diagnosed Structural Congenital Anomalies

OBJECTIVE To provide information to genetic counsellors, midwives, nurses, and physicians who are involved in the prenatal care of women dealing with prenatally diagnosed isolated or multiple structural congenital anomalies. OUTCOMES To provide better counselling for women and families who are dealing with the diagnosis of a fetal structural anomaly. EVIDENCE Published literature was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library for relevant articles using appropriate controlled vocabulary (e.g., structural congenital anomalies, prenatal ultrasound diagnosis of congenital anomalies, invasive testing results, and diagnosis of genetic syndromes; soft markers of aneuploidy were not included in this search) and key words. 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 material from between 1985 and 2008 incorporated in 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. VALUES The evidence obtained was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC). Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS Findings of isolated or multiple fetal anomalies on prenatal ultrasound examination always lead to stressful times for women and families. Although a proportion of such anomalies can be explained by chromosomal abnormalities (aneuploidy, unbalanced translocation, deletions, or duplications), others may represent recognizable syndromes with another genetic basis (microdeletion or autosomal dominant, recessive, or X-linked inheritance). Providing accurate information and relevant reproductive genetic counselling to these women and families will allow them to make informed decisions. This is not easily accomplished because of the limited information available prenatally. This document does not provide an extensive description of every syndrome but rather a framework of reference. No cost-benefit analysis is provided. RECOMMENDATIONS 1. When a fetal structural anomaly is identified, the pregnant woman should be offered a timely consultation with a trained genetic counsellor and with a maternal-fetal medicine specialist and/or a medical geneticist. The counselling should be unbiased and respectful of the patients choice, culture, religion, and beliefs. (III-A) 2. Patients should be informed that prenatal ultrasound at 18 to 20 weeks can detect major structural anomalies in approximately 60% of such cases. (II-2A) 3. When a fetal structural anomaly is suspected or identified, a referral to a tertiary ultrasound unit should be made as soon as possible to optimize therapeutic options. (II-2A) 4. In ongoing pregnancies with fetal structural anomalies, ultrasound examination should be repeated (at a frequency depending on the anomaly) to assess the evolution of the anomaly and attempt to detect other anomalies not previously identified, as this may influence the counselling as well as the obstetrical or perinatal management. (II-2B) 5. Once a fetal structural anomaly is identified by 2-D ultrasound, other imaging techniques such as fetal echocardiography, 3-D obstetrical ultrasound, ultrafast fetal MRI, and, occasionally, fetal X-ray and fetal CT scan (using a low-dose protocol) may be helpful in specific cases. (II-2A) 6. Parental imaging should be considered in specific cases, depending on the fetal anomaly identified (e.g., potential dominant inheritance). (III-A) 7. Parental blood testing and invasive prenatal testing may also be required to clarify the diagnosis for a fetus with isolated or multiple structural anomalies. (II-2A) 8. Women should receive information regarding the abnormal ultrasound findings in a clear, sympathetic, and timely fashion, and in a supportive environment that ensures privacy. Referral to the appropriate pediatric or surgical subspecialist(s) should be considered to provide the most accurate information possible concerning the anomaly or anomalies and the associated prognosis. (II-2 B) 9. Parents should be informed that major or minor fetal structural anomalies, whether isolated or multiple, may be part of a genetic syndrome, sequence, or association, despite a normal fetal karyotype. (III-A) 10. If early or urgent postnatal management may be required, delivery at a centre that can provide the appropriate neonatal care should be considered. (III-A) 11. When any congenital structural anomaly has been identified prenatally, a comprehensive newborn assessment is essential for diagnosis and counselling on the etiology, prognosis, and recurrence risk for future pregnancies, especially when the etiology has not been clearly identified prenatally. (III-A) 12. In cases of termination of pregnancy, stillbirth, or neonatal death, the health professional should encourage the performance of a complete autopsy by a perinatal or pediatric pathologist to provide maximum information on the diagnosis and etiology of the structural fetal anomaly or anomalies. When a complete autopsy is refused, the health professional should encourage the performance of at least a partial or external autopsy (including X-rays and photographs). (III-A) VALIDATION: This committee opinion has been prepared by the Genetics Committee of the SOGC and approved by the Executive of the SOGC.