Michiel C. Van den Hof

Neonatal outcomes with placenta previa

OBJECTIVE To identify neonatal complications associated with placenta previa. METHODS This was a population-based, retrospective cohort study involving all singleton deliveries in Nova Scotia from 1988 to 1995. The study group consisted of all completed singleton pregnancies complicated by placenta previa; all other singleton pregnancies were considered controls. Patient information was collected from the Nova Scotia Atlee perinatal database. Neonatal complications were evaluated while controlling for potential confounders. The data were analyzed using chi2, Fisher exact test, and multiple logistic regression. RESULTS Among 92,983 pregnancies delivered during the study period, 305 cases of placenta previa were identified (0.33%). After controlling for potential confounders, neonatal complications significantly associated with placenta previa included major congenital anomalies (odds ratio [OR] 2.48), respiratory distress syndrome (OR 4.94), and anemia (OR 2.65). The perinatal mortality rate associated with placenta previa was 2.30% (compared with 0.78% in controls) and was explained by gestational age at delivery, occurrence of congenital anomalies, and maternal age. Although there was a higher rate of preterm births in the placenta previa group (46.56% versus 7.27%), there was no difference in birth weights between groups after controlling for gestational age at delivery. CONCLUSION Neonatal complications of placenta previa included preterm birth, congenital anomalies, respiratory distress syndrome, and anemia. There was no increased occurrence of fetal growth restriction.

Association Between Maternal Chronic Conditions and Congenital Heart Defects A Population-Based Cohort Study

Background— This study quantifies the association between maternal medical conditions/illnesses and congenital heart defects (CHDs) among infants. Methods and Results— We carried out a population-based study of all mother-infant pairs (n=2 278 838) in Canada (excluding Quebec) from 2002 to 2010 using data from the Canadian Institute for Health Information. CHDs among infants were classified phenotypically through a hierarchical grouping of International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Canada codes. Maternal conditions such as multifetal pregnancy, diabetes mellitus, hypertension, and congenital heart disease were defined by use of diagnosis codes. The association between maternal conditions and CHDs and its subtypes was modeled using logistic regression with adjustment for maternal age, parity, residence, and other factors. There were 26 488 infants diagnosed with CHDs at birth or at rehospitalization in infancy; the overall CHD prevalence was 116.2 per 10 000 live births, of which the severe CHD rate was 22.3 per 10 000. Risk factors for CHD included maternal age ≥40 years (adjusted odds ratio [aOR], 1.48; 95% confidence interval [CI], 1.39–1.58), multifetal pregnancy (aOR, 4.53; 95% CI, 4.28–4.80), diabetes mellitus (type 1: aOR, 4.65; 95% CI, 4.13–5.24; type 2: aOR, 4.12; 95% CI, 3.69–4.60), hypertension (aOR, 1.81; 95% CI, 1.61–2.03), thyroid disorders (aOR, 1.45; 95% CI, 1.26–1.67), congenital heart disease (aOR, 9.92; 95% CI, 8.36–11.8), systemic connective tissue disorders (aOR, 3.01; 95% CI, 2.23–4.06), and epilepsy and mood disorders (aOR, 1.41; 95% CI, 1.16–1.72). Specific CHD subtypes were associated with different maternal risk factors. Conclusions— Several chronic maternal medical conditions, including diabetes mellitus, hypertension, connective tissue disorders, and congenital heart disease, confer an increased risk of CHD in the offspring.

Spina bifida before and after folic acid fortification in Canada.

BACKGROUND In 1998, fortification of a large variety of cereal products with folic acid became mandatory in Canada. A multicentric study was carried out to assess the impact of this policy on the frequency of NTDs. The present analysis focused on spina bifida. METHODS The study population included approximately 2 million livebirths, stillbirths, and terminations of pregnancies because of fetal anomalies among women residing in seven Canadian provinces, from 1993 to 2002. Spina bifida cases were divided according to the upper limit of the defect: upper (cranial, cervical, or thoracic) and lower (lumbar or sacral) defects. Based on published results of red blood cell folate tests, the study period was divided into prefortification, partial fortification, and full fortification periods. RESULTS A total of 1,286 spina bifida cases were identified: 51% livebirths, 3% stillbirths, and 46% terminations. Prevalence decreased from 0.86/1,000 in the prefortification to 0.40 in the full fortification period, while the proportion of upper defects decreased from 32% to 13%. Following fortification, regional variations in the prevalence and distribution of sites almost disappeared. CONCLUSIONS Results confirmed the etiologic heterogeneity of spina bifida and the more pronounced effect of folic acid in decreasing the risk of the more severe clinical presentations.

Single umbilical artery risk factors and pregnancy outcomes.

OBJECTIVE: To identify risk factors for fetuses and neonates with single umbilical artery and isolated single umbilical artery (single umbilical artery in the absence of chromosomal abnormalities and structural abnormalities) and to assess whether there is an increased risk for complications during pregnancy, labor, and delivery, and for perinatal morbidity and mortality. METHODS: A population-based retrospective cohort analysis of deliveries in Nova Scotia, Canada, between 1980 and 2002 was conducted using the Nova Scotia Atlee Perinatal Database. Risk factors and outcomes for single umbilical artery and isolated single umbilical artery pregnancies were compared with three-vessel-cord pregnancies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each outcome using multiple logistic regression to adjust for confounding factors. Separate models were run for single umbilical artery and isolated single umbilical artery. RESULTS: There were 203,240 fetuses and neonates available for analysis, with 885 (0.44%) having single umbilical artery and 725 (0.37%) having isolated single umbilical artery. Single umbilical artery fetuses and neonates had a 6.77 times greater risk of congenital anomalies and 15.35 times greater risk of chromosomal abnormalities. The most common congenital anomalies in chromosomally normal fetuses and neonates were genitourinary (6.48%), followed by cardiovascular (6.25%) and musculoskeletal (5.44%). For isolated single umbilical artery, placental abnormalities (OR 3.63, 95% CI 3.01–4.39), hydramnios (OR 2.80, 95% CI 1.42–5.49), and amniocentesis (OR 2.52, 95% CI 1.82–3.51) occurred more frequently than with three vessel cords. Neonates with single umbilical artery and isolated single umbilical artery had increased rates of prematurity, growth restriction, and adverse neonatal outcomes. CONCLUSION: Fetuses and neonates with single umbilical artery and isolated single umbilical artery are at increased risk for adverse outcomes. Identification of single umbilical artery is important for prenatal diagnosis of congenital anomalies and aneuploidy. Increased surveillance with isolated single umbilical artery may improve pregnancy outcomes. LEVEL OF EVIDENCE: II

Effect of Folic Acid Food Fortification in Canada on Congenital Heart Disease Subtypes

Background: Previous studies have yielded inconsistent results for the effects of periconceptional multivitamins containing folic acid and of folic acid food fortification on congenital heart defects (CHDs). Methods: We carried out a population-based cohort study (N=5 901 701) of all live births and stillbirths (including late-pregnancy terminations) delivered at ≥20 weeks’ gestation in Canada (except Québec and Manitoba) from 1990 to 2011. CHD cases were diagnosed at birth and in infancy (n=72 591). We compared prevalence rates and temporal trends in CHD subtypes before and after 1998 (the year that fortification was mandated). An ecological study based on 22 calendar years, 14 geographic areas, and Poisson regression analysis was used to quantify the effect of folic acid food fortification on nonchromosomal CHD subtypes (n=66 980) after controlling for changes in maternal age, prepregnancy diabetes mellitus, preterm preeclampsia, multiple birth, and termination of pregnancy. Results: The overall birth prevalence rate of CHDs was 12.3 per 1000 total births. Rates of most CHD subtypes decreased between 1990 and 2011 except for atrial septal defects, which increased significantly. Folic acid food fortification was associated with lower rates of conotruncal defects (adjusted rate ratio [aRR], 0.73, 95% confidence interval [CI], 0.62–0.85), coarctation of the aorta (aRR, 0.77; 95% CI, 0.61–0.96), ventricular septal defects (aRR, 0.85; 95% CI, 0.75–0.96), and atrial septal defects (aRR, 0.82; 95% CI, 0.69–0.95) but not severe nonconotruncal heart defects (aRR, 0.81; 95% CI, 0.65–1.03) and other heart or circulatory system abnormalities (aRR, 0.98; 95% CI, 0.89–1.11). ConclusionS: The association between food fortification with folic acid and a reduction in the birth prevalence of specific CHDs provides modest evidence for additional benefit from this intervention.

Fetal Sex Determination and Disclosure

The Supreme Court of Canada (McInerney v. MacDonald 1992) concluded that a patient is entitled to examine and copy from his or her medical record all information the physician considered in administering advice or treatment.2 The physician must justify denying access to that record on the basis that doing so would not be in the patient’s best interest. On the basis of this ruling, it is legally difficult to defend nondisclosure. Disclosure of fetal sex upon request respects a woman’s rightful autonomy over personal health information. Those who oppose fetal sex determination and disclosure have concerns about risk for error, the time involved in making a determination of fetal sex, and that the information may lead women to abort pregnancies when the fetus is not the wanted sex. The risk for error is estimated to be less than 3%, but prospective parents should be made aware of this possibility with disclosure.3 There is no evidence that fetal sex determination during a complete obstetric ultrasound will extend the examination time.3 A small number of pregnant women may consider abortion when the fetus is the unwanted sex; however, this is best addressed by the health professionals who are providing care for these women. Diagnostic imaging units that prefer to maintain a policy of nondisclosure of fetal sex should include the information in their reports. This would allow the referring physicians or midwives to disclose the fetal sex at their patients’ request. In summary, SOGC recommends that fetal genitalia be examined as a part of the routine second trimester obstetric ultrasound and that this examination not be prolonged or repeated if no abnormalities are seen but sex determination is inconclusive. If fetal sex has been determined, a patient’s request for disclosure should be respected, either directly or in a report to the referring health professional.

Mobile remote-presence devices for point-of-care health care delivery

Timely access to effective medical care is a substantial challenge common to both developed and developing countries. In industrialized nations, barriers to medical care caused by distance and lack of adequate health care infrastructure and medical expertise have a negative impact on the provision

Joint SOGC/CAR Policy Statement on Non-medical Use of Fetal Ultrasound

This document reflects emerging clinical and scientific advances on the date issued and is subject to change. The information should not be construed as dictating an exclusive course of treatment or procedure to be followed. Local institutions can dictate amendments to these opinions. They should be well documented if modified at the local level. None of these contents may be reproduced in any form without prior written permission of the SOGC. This joint policy statement has been prepared by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada and the Point of Care Ultrasound Working Group of the Canadian Association of Radiologists and approved by the Executive and Council of the Society of Obstetrics and Gynaecology of Canada and the Board of Directors of the Canadian Association of Radiologists.

Peripartum Factors Predicting the Need for Increased Doses of Postpartum Rhesus Immune Globulin

OBJECTIVE To evaluate the need for increased doses of postpartum rhesus immune globulin in a woman at risk for rhesus alloimmunization. METHODS Using data from the Nova Scotia Atlee Perinatal Database (NSAPD) and the Rh Program of Nova Scotia Database, Rh negative women delivering infants with a birth weight greater than 500 grams and gestational age greater than 20 weeks at the IWK Health Centre from 1998 to 2007 were identified. Within this population, Rh(D) negative women who received both antepartum and postpartum anti-D prophylaxis were identified. Logistic regression was used to estimate peripartum predictive factors for elevated postpartum Kleihauer and the need for administration of additional rhesus immune globulin. RESULTS The NSAPD and Rh Program Database identified 4323 Rh negative women who received both antepartum and postpartum prophylaxis from 1998 and 2007. Following logistic regression, a postpartum Kleihauer value of > 0.2% was found to be predicted by multiparity (OR 1.47; 95% CI 1.03 to 2.08), multiple gestation (OR 3.03; 95% CI 1.61 to 5.70), antepartum risks for fetomaternal hemorrhage (OR 63.6; 95% CI 30.2 to 134), and Caesarean section (OR 2.03; 95% CI 1.42 to 2.91). A postpartum Kleihauer value of > 0.5% was found to be predicted by antepartum risks for fetomaternal hemorrhage (OR 29.1; 95% CI 12.9 to 65.5), and Caesarean section (OR 2.01; 95% CI 1.18 to 3.42). CONCLUSION While there are recognized events that increase the risk for Rh(D) alloimmunization, multiparity, multiple gestation, and Caesarean section should be additional factors for consideration, especially with rising rates of CS. Adequate postpartum prophylaxis may be optimized by conducting routine screening for fetomaternal hemorrhage, especially when lower doses of Rh(D) immune globulin are administered.

Utilisation non médicale de l’échographie fœtale

La présente déclaration de principe commune a été rédigée par le comité d’imagerie diagnostique de la Société des obstétriciens et gynécologues du Canada, et le Groupe de travail sur l’échographie au point de service de l’Association canadienne des radiologistes, et approuvée par le comité exécutif et le Conseil de la Société des obstétriciens et gynécologues du Canada, et le conseil d’administration de l’Association canadienne des radiologistes.