Impact of maternal pulmonary insufficiency on fetal growth in pregnancy.

Rationale: It is known that fetal growth is usually proportional to left-sided cardiac output (CO), which parallels the right-sided CO and that congenital right-sided lesions are usually associated with better perinatal outcomes than left-sided lesions.Objective: Our objective was to document whether newborns from mothers with severe residual pulmonary valve insufficiency (PI) after surgical tetralogy of Fallot (TOF) or pulmonary valve stenosis (PS) correction have lower birth weight (BW) than newborns from mothers with absent, mild, or moderate PI.Methods: This is a retrospective cohort study of women affected with repaired TOF and corrected PS with varied severity of residual PI. Exclusion criteria were: left ventricular dysfunction, left-sided valvular heart disease, other right-sided structural heart disease, chronic hypertension, substance addiction, and incomplete follow-up. Pregnancies were divided into three groups: absent or mild PI, moderate PI, and severe PI. A generalized linear model with normal dependent variable distribution was built and the parameter estimation made with Generalized Estimation Equations (GEE) to take into account repeated mother in data. Variables such as gestational age at birth, maternal age, smoking, and body mass index were tested with bivariate analyses to assess their effect on BW. Only gestational age remained in the adjusted model.Results: A total of 45 patients were included (33 TOF and 12 PS) and 97 pregnancies were reported: 22 miscarriages (22.7%) (15 TOF, 7 PS) and 75 successful pregnancies (57 TOF, 18 PS). The patients were divided into three groups: 1) absent or mild PI, 2) moderate PI, and 3) severe PI groups, which comprised, respectively, 29 (15 TOF, 4 PS), 20 (10 TOF, 1 PS), and 26 successful pregnancies (8 TOF, 7 PS). Using three levels of PI (absent or mild, moderate, and severe), the unadjusted model showed a significant effect of level of PI on BW (p = .0118), as well as the adjusted model (p = .0263) with gestational age as a covariate. The estimated mean newborn's BW was 3055.8 g in the severe PI group, 3151.0 g in the moderate PI group, and 3376.4 g in the absent or mild group when adjusted for gestational age. Hence, we estimated that the mean newborn's BW is 321 g lower in the severe PI group compared with absent or mild PI group ((CI: 572.3; -68.9), p = .0087).Conclusions: Pregnancy is usually well tolerated in repaired TOF and corrected PS. Severe PI either from repaired TOF or PS is at higher risk of lower newborn's BW. Special attention must be paid to the severity of PI. Fetal growth surveillance in the third trimester is warranted.

Obstetric and cardiac outcomes in women with Marfan syndrome and an aortic root diameter ≤ 45mm.

OBJECTIVE: To assess obstetric and aortic outcomes in women with Marfan Syndrome according to aortic root diameter, in view of recommendations for caesarean delivery when the aortic root diameter is ≥40 mm in the 2010 American guidelines versus >45 mm in the 2011 European guidelines. STUDY DESIGN: In this retrospective cohort study conducted at Sainte-Justine Mother and Child Tertiary Hospital, 27 pregnancies in 20 women with Marfan Syndrome as defined by the international criteria, were followed prospectively between 1994 and 2017, after excluding women with prior aortic surgery. Obstetric and aortic outcomes were compared in 2 groups according to aortic root diameter: < 40 mm (21 pregnancies) and 40-45 mm (6 pregnancies). RESULTS: 21/27 women had a vaginal delivery. The caesarean section rate was 23.8% and 16.7% in women with diameter <40 mm and 40-45 mm respectively (p-value = 1), and perinatal outcome was similar across groups. Two women with a prepregnancy aortic root diameter <40 mm developed an acute type B dissection during the third trimester. Both had a family history of aortic dissection. CONCLUSIONS: Vaginal delivery with rigorous pain control and avoidance of Valsalva maneuver may be safely considered in women with Marfan Syndrome and an aortic root diameter ≤45 mm. The risk of type B aortic dissection during pregnancy is hard to predict. Other factors such as family history of dissection and descending aorta size may play an important role, and this may modify our counselling.

Oxidized low-density lipoproteins in cord blood from neonates with intra-uterine growth restriction.

OBJECTIVE: We verified whether oxidative stress indices (oxidized low-density lipoproteins and malondialdehyde) and inflammatory biomarkers (circulating C-reactive protein, interleukin-6, tumour necrosis factor-α, serum amyloid A and soluble intercellular vascular cell adhesion molecule) are increased in the umbilical vein of placental insufficiency induced intra-uterine growth restricted neonates. STUDY DESIGN: The prospective cohort study, involving 3 tertiary care centers, consists of 200 consecutively recruited pregnant women carrying twins. We chose the twin pregnancy model because both fetuses share the same maternal environment, thereby avoiding potential confounding factors when comparing oxidative stress and inflammation biomarkers. We analysed only twin pairs with one with intra-uterine growth restriction (N=38) defined as fetal growth<10th percentile with abnormal Doppler of the umbilical artery. Blood samples were taken at birth from the umbilical vein. Intra-pair comparisons on the biomarkers were performed using the Student paired t-test. RESULTS: We observed increased cord blood levels of oxidized low-density lipoproteins, (2.394 ± .412 vs 1.296 ± .204, p=.003) but not of malondialdehyde in growth restricted neonates when compared to their normal counterparts. Although indices of inflammation tended to be increased in cord blood from growth restricted newborns, the difference did not reach statistical significance. CONCLUSION: In the twin model, intra-uterine growth restriction is associated with low-density lipoprotein oxidation without apparent dysregulation of inflammation biomarkers. CONDENSATION: Increased oxidized low-density lipoproteins are observed in growth restricted twins compared to their co-twins with normal growth at birth.

An international trial of antioxidants in the prevention of preeclampsia (INTAPP).

OBJECTIVE: We sought to investigate whether prenatal vitamin C and E supplementation reduces the incidence of gestational hypertension (GH) and its adverse conditions among high- and low-risk women. STUDY DESIGN: In a multicenter randomized controlled trial, women were stratified by the risk status and assigned to daily treatment (1 g vitamin C and 400 IU vitamin E) or placebo. The primary outcome was GH and its adverse conditions. RESULTS: Of the 2647 women randomized, 2363 were included in the analysis. There was no difference in the risk of GH and its adverse conditions between groups (relative risk, 0.99; 95% confidence interval, 0.78-1.26). However, vitamins C and E increased the risk of fetal loss or perinatal death (nonprespecified) as well as preterm prelabor rupture of membranes. CONCLUSION: Vitamin C and E supplementation did not reduce the rate of preeclampsia or GH, but increased the risk of fetal loss or perinatal death and preterm prelabor rupture of membranes.

Fetal programming of atherosclerosis: possible role of the mitochondria.

Growing evidence indicates that being small size at birth from malnutrition is associated with an increased risk of developing type 2 diabetes (T2D), metabolic syndrome and cardiovascular disease in adulthood. Atherosclerosis is common to these aforementioned disorders, and oxidative stress and chronic inflammation are now considered as initiating events in its development, with endothelial cell dysfunction being an early, fundamental step. According to the fetal programming hypothesis, growth-restricted neonates exposed to placental insufficiency exhibit endothelial cell dysfunction very early in life that later on predisposes them to atherosclerosis. Although many investigations have reported early alterations in vascular function in children and adolescents with low birth weight, the mechanisms of such fetal programming of atherosclerosis remain largely unknown. Experimental studies have demonstrated that low birth weight infants are prenatally subjected to conditions of oxidative stress and inflammation that might be involved in the later occurrence of atherosclerosis. Arterial endothelial dysfunction has been encountered in term infants, children and young adults with low birth weight. The loss of appropriate endothelium function with decreased nitric oxide production or activity, manifested as impaired vasodilatation, is considered a basic step in atherosclerosis development and progression. Several lines of evidence indicate that mitochondrial damage is central to this process and that reactive oxygen species (ROS) may act as a double-edged sword. On the one hand, it is well-accepted that the mitochondria are a major source of chronic ROS production under physiological conditions. On the other hand, it is known that ROS generation damages lipids, proteins and mitochondrial DNA, leading to dysregulated mitochondrial function. Elevated mitochondrial ROS production is associated with endothelial cell dysfunction as well as vascular smooth muscle cell proliferation and apoptosis. Smoking, obesity, insulin-resistant T2D, hypercholesterolemia, hyperglycaemia and hypertriglyceridaemia, major, traditional precursors of atherosclerosis, are all linked to mitochondrial dysfunction. This review focuses on proof of in utero programming resulting from chronic exposure to oxidative stress and inflammation as a cause of atherosclerosis. Endothelial cell dysfunction may be the initial injury arising from adverse antenatal conditions and responsible for the early changes in vascular function seen in children. After considering the critical role of the mitochondria in atherogenesis through endothelial function abnormalities, we propose that placental mitochondrial dysfunction is present in cases of placental insufficiency and may be critical in fetal programming of atherosclerosis.

Canadian Consensus on cardiac transplantation in pediatric and adult congenital heart disease patients 2004: executive summary.

Cardiac transplantation is an acceptable therapeutic option for the pediatric age group and for adult patients with congenital heart disease. There are a myriad of clinical diagnoses in these two patient populations. Survival has continued to improve, with graft half-lives of 14 years and greater in pediatric heart transplantation patients. There are issues unique to these patient populations in relation to heart transplantation for which the present document summarizes the relevant literature and presents management guidelines. Donor availability remains a major limiting factor in organ transplantation at present. Efforts need to be made to increase organ donor awareness, identify potential donors and aggressively manage marginal donors. Indications for transplantation and determination of timing of listing continue to be challenging due to a lack of evidence-based guidelines specifically for prognostic indices of outcome and pretransplant survival. The current status system for listing patients for transplantation does not necessarily reflect the typical clinical course of deterioration experienced by these two patient populations; therefore, consideration needs to be given to a parallel listing strategy. Evidence is accumulating pointing to an advantage to performing transplantations in patients in early infancy. ABO-incompatible heart transplantation has lead to a reduction in waiting time and waiting list mortality. Care of children after heart transplantation must take into consideration physical growth and multisystem development; stage of immunological maturation; intellectual, emotional and social maturation; educational activities; and other pediatric quality of life parameters. Post-transplantation issues are somewhat different, including rejection, coronary artery disease, malignancies and infections. Efforts need to be made to support multicentre trials to determine optimal treatment protocols.

Embolic myocardial infarction in a pregnant woman with a mechanical heart valve on low molecular weight heparin.

Even with continuing technical improvements in prosthesis design and the development of less thrombogenic materials, mechanical valve prostheses still carry a thromboembolic risk significant enough to warrant long-term anticoagulation therapy. Optimal anticoagulation is especially crucial during pregnancy due to the hypercoagulable state that rapidly develops after conception. Conventional anticoagulation therapy with coumarin derivatives is associated with risks of teratogenicity and hemorrhage for the fetus, and thromboembolic and hemorrhagic complications for the mother. As a result, other forms of anticoagulation, such as unfractionated or low molecular weight heparin, have been advocated as an alternative in selected cases. The present report describes a case of embolic myocardial infarction occurring in a pregnant woman with an aortic bileaflet mechanical valve prosthesis while on therapeutic low molecular weight heparin after only one dose was withheld before amniocentesis.

Prevention of Rh alloimmunization.

OBJECTIVE: To provide guidelines on use of anti-D prophylaxis to optimize prevention of rhesus (Rh) alloimmunization in Canadian women. OUTCOMES: Decreased incidence of Rh alloimmunization and minimized practice variation with regards to immunoprophylaxis strategies. EVIDENCE: The Cochrane Library and MEDLINE were searched for English-language articles from 1968 to 2001, relating to the prevention of Rh alloimmunization. Search terms included: Rho(D) immune globulin, Rh iso- or allo-immunization, anti-D, anti-Rh, WinRho, Rhogam, and pregnancy. Additional publications were identified from the bibliographies of these articles. All study types were reviewed. Randomized controlled trials were considered evidence of highest quality, followed by cohort studies. Key individual studies on which the principal recommendations are based are referenced. Supporting data for each recommendation is briefly summarized with evaluative comments and referenced. VALUES: The evidence collected was reviewed by the Maternal-Fetal Medicine and Genetics Committees 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 Exam. RECOMMENDATIONS: 1. Anti-D Ig 300 microg IM or IV should be given within 72 hours of delivery to a postpartum nonsensitized Rh-negative woman delivering an Rh-positive infant. Additional anti-D Ig may be required for fetomaternal hemorrhage (FMH) greater than 15 mL of fetal red blood cells (about 30 mL of fetal blood). Alternatively, anti-D Ig 120 microg IM or IV may be given within 72 hours of delivery, with testing and additional anti-D Ig given for FMH over 6 mL of fetal red blood cells (12 mL fetal blood). (I-A) 2. If anti-D is not given within 72 hours of delivery or other potentially sensitizing event, anti-D should be given as soon as the need is recognized, for up to 28 days after delivery or other potentially sensitizing event. (III-B) 3. There is poor evidence regarding inclusion or exclusion of routine testing for postpartum FMH, as the cost-benefit of such testing in Rh mothers at risk has not been determined. (III-C) 4. Anti-D Ig 300 microg should be given routinely to all Rh-negative nonsensitized women at 28 weeks' gestation when fetal blood type is unknown or known to be Rh-positive. Alternatively, 2 doses of 100-120 microg may be given (120 microg being the lowest currently available dose in Canada): one at 28 weeks and one at 34 weeks. (I-A) 5. All pregnant women (D-negative or D-positive) should be typed and screened for alloantibodies with an indirect antiglobulin test at the first prenatal visit and again at 28 weeks. (III-C) 6. When paternity is certain, Rh testing of the baby's father may be offered to all Rh-negative pregnant women to eliminate unnecessary blood product administration. (III-C) 7. A woman with "weak D" (also known as Du-positive) should not receive anti-D. (III-D) 8. A repeat antepartum dose of Rh immune globulin is generally not required at 40 weeks, provided that the antepartum injection was given no earlier than 28 weeks' gestation. (III-C) 9. After miscarriage or threatened abortion or induced abortion during the first 12 weeks of gestation, nonsensitized D-negative women should be given a minimum anti-D of 120 microg. After 12 weeks' gestation, they should be given 300 microg. (II-3B) 10. At abortion, blood type and antibody screen should be done unless results of blood type and antibody screen during the pregnancy are available, in which case antibody screening need not be repeated. (III-B) 11. Anti-D should be given to nonsensitized D-negative women following ectopic pregnancy. A minimum of 120 microg should be given before 12 weeks' gestation and 300 microg after 12 weeks' gestation. (III-B) 12. Anti-D should be given to nonsensitized D-negative women following molar pregnancy because of the possibility of partial mole. Anti-D may be withheld if the diagnosis of complete mole is certain. (III-B) 13. At amniocentesis, anti-D 300 microg should be given to nonsensitized D-negativeesis, anti-D 300 microg should be given to nonsensitized D-negative women. (II-3B) 14. Anti-D should be given to nonsensitized D-negative women following chorionic villous sampling, at a minimum dose of 120 microg during the first 12 weeks' gestation, and at a dose of 300 microg after 12 weeks' gestation. (II-B) 15. Following cordocentesis, anti-D Ig 300 microg should be given to nonsensitized D-negative women. (II-3B) 16. Quantitative testing for FMH may be considered following events potentially associated with placental trauma and disruption of the fetomaternal interface (e.g., placental abruption, blunt trauma to the abdomen, cordocentesis, placenta previa with bleeding). There is a substantial risk of FMH over 30 mL with such events, especially with blunt trauma to the abdomen. (III-B) 17. Anti-D 120 microg or 300 microg is recommended in association with testing to quantitate FMH following conditions potentially associated with placental trauma and disruption of the fetomaternal interface (e.g., placental abruption, external cephalic version, blunt trauma to the abdomen, placenta previa with bleeding). If FMH is in excess of the amount covered by the dose given (6 mL or 15 mL fetal RBC), 10 microg additional anti-D should be given for every additional 0.5 mL fetal red blood cells. There is a risk of excess FMH, especially when there has been blunt trauma to the abdomen. (III-B) 18. Verbal or written informed consent must be obtained prior to administration of the blood product Rh immune globulin. (III-C) VALIDATION: These guidelines have been reviewed by the Maternal-Fetal Medicine Committee and the Genetics Committee, with input from the Rh Program of Nova Scotia. Final approval has been given by the Executive and Council of the Society of Obstetricians and Gynaecologists of Canada.

RETIRED: Screening for gestational diabetes mellitus.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

RETIRED: Cystic fibrosis carrier testing in pregnancy in Canada.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.