Differential impact of maternal and paternal ethnicity on the pattern of fat distribution in infants at age 3 months

BACKGROUND

As ethnicity is typically recorded as a single demographic variable in clinical studies, little is known about the relative impact of maternal vs. paternal ethnicity on fat distribution.

OBJECTIVES

The objective of this study was to determine whether there is a differential impact of maternal and paternal ethnicity on infant adiposity.

METHODS

Three hundred fifty-five infants underwent anthropometric assessment at age 3 months, including skin-fold thickness (SFT) measurement at subscapular, suprailiac and triceps. Maternal (M) and paternal (P) ethnicity were classified as white (M = 241, P = 252), Asian (M = 50, P = 42) or other (M = 64, P = 61).

RESULTS

Infants with either Asian mother (compared with white) or Asian father (compared with white) had increased subscapular, suprailiac and triceps SFT (all P < 0.05). On logistic regression analysis, however, only maternal Asian ethnicity (compared with white) independently predicted the likelihood of an infant being in the highest tertile for SFT at subscapular (odds ratio [OR] = 2.72, 95% confidence interval 1.17-6.34, P = 0.02), suprailiac (OR = 3.56, 1.51-8.42, P = 0.004) and triceps (OR = 3.26, 1.40-7.55, P = 0.005). In contrast, paternal Asian ethnicity was independently associated with sum of SFT only (OR = 2.46, 1.02-5.97, P = 0.04).

CONCLUSION

Maternal and paternal Asian ethnicity have differential effects on infant fat distribution. Future clinical studies on obesity and fat composition should consider the distinct contributions of both parents to the ethnic classification of participants.

Effect of maternal gestational diabetes on the cardiovascular risk factor profile of infants at 1 year of age

BACKGROUND AND AIM

Offspring of women with gestational diabetes (GDM) exhibit an adverse cardiovascular risk factor profile by as early as age 5 years. Recently, maternal glycemia has been associated with epigenetic modification of genes on the fetal side of the placenta, including those encoding emerging risk factors (adiponectin, leptin), suggesting that vascular differences may emerge even earlier in life. Thus, we sought to evaluate cardiovascular risk factors and determinants thereof in 1-year-old infants of women with and without GDM.

METHODS AND RESULTS

Traditional (glucose, lipids) and emerging (C-reactive protein (CRP), adiponectin, leptin) risk factors were assessed in pregnancy in 104 women with (n = 36) and without GDM (n = 68), and at age 1-year in their offspring. In pregnancy, women with GDM had higher triglycerides (2.49 vs 2.10 mmol/L, p = 0.04) and CRP (5.3 vs 3.6 mg/L, p = 0.03), and lower adiponectin (7.3 vs 8.5 μg/mL, p = 0.04) than did their peers. At age 1-year, however, there were no differences in cardiovascular risk factors (including adiponectin) between the infants of women with and without GDM. Of note, maternal and infant adiponectin levels were associated in the non-GDM group (r = 0.39, p = 0.001) but not in the GDM group (r = 0.07, p = 0.67). Furthermore, on multiple linear regression analyses, maternal adiponectin emerged as an independent predictor of infant adiponectin in the non-GDM group only (beta = 776.1, p = 0.0065).

CONCLUSION

Infants of women with and without GDM have a similar cardiovascular risk factor profile at age 1-year. However, there are differences in their early-life determinants of adiponectin that may be relevant to the subsequent vascular risk of GDM offspring.

Maternal pregravid weight is the primary determinant of serum leptin and its metabolic associations in pregnancy, irrespective of gestational glucose tolerance status

CONTEXT

Several previous studies have investigated circulating levels of the adipokine leptin in relation to gestational diabetes mellitus (GDM). However, these studies have yielded markedly conflicting results, including increased, decreased, and unchanged leptin levels in women with GDM as compared with their peers.

OBJECTIVE

We sought to evaluate the metabolic determinants of serum leptin in a well-characterized cohort reflecting the full spectrum of glucose intolerance in pregnancy.

DESIGN, SETTING, AND PARTICIPANTS

Metabolic characterization, including oral glucose tolerance test (OGTT) and measurement of serum leptin, insulin, lipids, adiponectin, and C-reactive protein, was performed in 817 pregnant women. The OGTT identified 198 women with GDM, 142 with gestational impaired glucose tolerance, and 477 with normal glucose tolerance.

RESULTS

Median leptin (ng/ml) did not differ between the normal glucose tolerance (33.7), gestational impaired glucose tolerance (36.3), and GDM (36.4) groups (P = 0.085). On univariate correlation analysis, leptin was most strongly associated with prepregnancy body mass index (BMI) (r = 0.54, P < 0.0001), fasting insulin (r = 0.60, P < 0.0001), and C-reactive protein (r = 0.38, P < 0.0001) but only weakly associated with area under the glucose curve (AUC(glucose)) on the OGTT (r = 0.10, P = 0.0066). On multiple linear regression analysis, the strongest independent determinant of leptin was prepregnancy BMI (t = 11.55, P < 0.0001), whereas AUC(glucose) was not a significant predictor (t = -0.95, P = 0.34). Furthermore, although its respective associations with fasting insulin, triglycerides, and adiponectin varied across tertiles of prepregnancy BMI, leptin was not significantly associated with AUC(glucose) in any BMI tertile.

CONCLUSIONS

Pregravid BMI, rather than gestational glucose tolerance, is the primary determinant of serum leptin concentration in pregnancy.

The postpartum cardiovascular risk factor profile of women with isolated hyperglycemia at 1-hour on the oral glucose tolerance test in pregnancy

BACKGROUND AND AIMS

Women with gestational diabetes mellitus (GDM) have an enhanced cardiovascular risk factor profile at 3-months postpartum and an elevated risk of future cardiovascular disease, as compared to their peers. Recently, it has emerged that even mild dysglycemia on antepartum oral glucose tolerance test (OGTT) predicts an increased risk of future cardiovascular disease, although it is not known whether there exists an identifiable high-risk subgroup within this patient population. Since gestational impaired glucose tolerance (GIGT) due to isolated hyperglycemia at 1-h during the OGTT (1-h GIGT) bears metabolic similarity to GDM, we hypothesized that, like GDM, 1-h GIGT may predict a high-risk postpartum cardiovascular phenotype.

METHODS AND RESULTS

In this prospective cohort study, 485 women underwent antepartum OGTT, followed by cardiovascular risk factor assessment at 3-months postpartum. The antepartum OGTT identified 4 gestational glucose tolerance groups: GDM (n = 137); 1-h GIGT (n = 39); GIGT at 2- or 3-h (2/3-h GIGT)(n = 50); and normal glucose tolerance (NGT)(n = 259). After adjustment for age, ethnicity, breastfeeding and waist circumference, mean levels of the following cardiovascular risk factors progressively increased from NGT to 2/3-h GIGT to 1-h GIGT to GDM: LDL cholesterol (p = 0.0026); total cholesterol:HDL (p = 0.0030); apolipoprotein B (p = 0.004); apolipoprotein B:apolipoprotein A1 (p = 0.026); leptin (p = 0.018); and C-reactive protein (p = 0.011).

CONCLUSIONS

Amongst women without GDM, 1-h GIGT predicts an enhanced postpartum cardiovascular risk factor profile. It thus emerges, that amongst young women with mild dysglycemia in pregnancy, those with 1-h GIGT may comprise an unrecognized patient population at risk for future cardiovascular disease.

Low adiponectin concentration during pregnancy predicts postpartum insulin resistance, beta cell dysfunction and fasting glycaemia

AIMS/HYPOTHESIS

The postpartum phase following gestational diabetes (GDM) is characterised by subtle metabolic defects, including the beta cell dysfunction that is believed to mediate the increased future risk of type 2 diabetes in this patient population. Low circulating levels of adiponectin and increased leptin and C-reactive protein (CRP) have recently emerged as novel diabetic risk factors, although their relevance to GDM and subsequent diabetes has not been characterised. Thus, we sought to determine whether adiponectin, leptin and CRP levels during pregnancy relate to the postpartum metabolic defects linking GDM with type 2 diabetes.

METHODS

Metabolic characterisation, including oral glucose tolerance testing, was undertaken in 487 women during pregnancy and at 3 months postpartum. Based on the antepartum OGTT, there were 137 women with GDM, 91 with gestational impaired glucose tolerance and 259 with normal glucose tolerance.

RESULTS

Adiponectin levels were lowest (p < 0.0001) and CRP levels highest (p = 0.0008) in women with GDM. Leptin did not differ between the glucose tolerance groups (p = 0.4483). Adiponectin (r = 0.41, p < 0.0001), leptin (r = -0.36, p < 0.0001) and CRP (r = -0.30, p < 0.0001) during pregnancy were all associated with postpartum insulin sensitivity (determined using the insulin sensitivity index of Matsuda and DeFronzo [IS(OGTT)]). Intriguingly, adiponectin levels were also related to postpartum beta cell function (insulinogenic index/HOMA of insulin resistance; r = 0.16, p = 0.0009). Indeed, on multiple linear regression analyses, adiponectin levels during pregnancy independently predicted both postpartum insulin sensitivity (t = 3.97, p < 0.0001) and beta cell function (t = 2.37, p = 0.0181), even after adjustment for GDM. Furthermore, adiponectin emerged as a significant negative independent determinant of postpartum fasting glucose (t = -3.01, p = 0.0027).

CONCLUSIONS/INTERPRETATION

Hypoadiponectinaemia during pregnancy predicts postpartum insulin resistance, beta cell dysfunction and fasting glycaemia, and hence may be relevant to the pathophysiology relating GDM with type 2 diabetes.

Decreased high-molecular-weight adiponectin in gestational diabetes: implications for the pathophysiology of Type 2 diabetes

AIMS

Low serum concentrations of the insulin-sensitizing protein adiponectin predict the development of incident Type 2 diabetes (T2DM). It has recently emerged that the anti-diabetic activity of adiponectin may be mediated by its high-molecular-weight (HMW) isoform, circulating levels of which are decreased in T2DM. The relevance of decreased HMW adiponectin to incident T2DM, however, has not been assessed. Since gestational diabetes (GDM) identifies a population of young women at high risk of future T2DM (i.e. representing an early stage in the natural history of the disease), we sought to determine if decreased HMW adiponectin is a feature of GDM.

METHODS

HMW and total adiponectin were measured in 121 women at the time of oral glucose tolerance testing (OGTT) in late pregnancy, following an abnormal glucose challenge test. Based on the OGTT, there were 41 women with and 80 without GDM.

RESULTS

Median HMW adiponectin concentration was lower in women with GDM (3.5 microg/ml) than in those without GDM (5.5 microg/ml) (P < 0.0001). After full adjustment for covariates, mean HMW adiponectin remained significantly lower in women with GDM compared with their peers (3.6 vs. 5.3 microg/ml, P = 0.0035). HMW adiponectin was positively associated with insulin sensitivity (IS(OGTT)) (r = 0.38, P < 0.0001) and pancreatic B-cell function [insulin secretion-sensitivity index (ISSI)] (r = 0.33, P = 0.0002) and inversely related to blood glucose levels, including area-under-the-glucose-curve during the OGTT (AUC(glucose)) (r = -0.31, P = 0.0007). On separate multiple linear regression analyses, HMW adiponectin emerged as an independent determinant of AUC(glucose), IS(OGTT) and ISSI, respectively, mirroring the relationships of total adiponectin.

CONCLUSIONS

HMW adiponectin is significantly decreased in women with GDM. Deficiency of HMW adiponectin may be an early event in the natural history of T2DM.

Adiponectin and beta cell dysfunction in gestational diabetes: pathophysiological implications

AIMS/HYPOTHESIS

Gestational diabetes mellitus (GDM) identifies a population of young women at high risk of developing type 2 diabetes and thus provides an excellent model for studying early events in the natural history of this disease. Adiponectin, a novel adipocyte-derived protein with insulin-sensitising properties, has been proposed as a factor linking insulin resistance and beta cell dysfunction in the pathogenesis of type 2 diabetes. We conducted the current investigation to determine whether adiponectin is associated with beta cell dysfunction in GDM.

METHODS

We studied 180 women undergoing OGTT in late pregnancy. Based on the OGTT results, participants were stratified into three groups: (1) NGT (n=93); (2) IGT (n=39); and (3) GDM (n=48). First-phase insulin secretion was determined using a validated index previously proposed by Stumvoll. Insulin sensitivity was assessed using the validated OGTT insulin sensitivity index of Matsuda and DeFronzo (IS(OGTT)).

RESULTS

To evaluate beta cell function in relation to ambient insulin sensitivity, an insulin secretion-sensitivity index (ISSI) was derived from the product of the Stumvoll index and the IS(OGTT), based on the existence of the predicted hyperbolic relationship between these two measures. Mean ISSI was highest in the NGT group (6,731), followed by that in the IGT group (4,976) and then that in the GDM group (3,300) (overall p<0.0001), compatible with the notion of declining beta cell function across these glucose tolerance groups. Importantly, adiponectin was significantly correlated with ISSI (r=0.34, p<0.0001), with a stepwise increase in mean ISSI observed per tertile of adiponectin concentration (trend p<0.0001). In multivariate linear regression analysis, ISSI was positively correlated with adiponectin and negatively correlated with GDM, IGT and C-reactive protein (r(2)=0.54).

CONCLUSIONS/INTERPRETATION

Adiponectin concentration is an independent correlate of beta cell function in late pregnancy. As such, adiponectin may play a key role in mediating insulin resistance and beta cell dysfunction in the pathogenesis of diabetes.

Hypoadiponectinaemia in South Asian women during pregnancy: evidence of ethnic variation in adiponectin concentration

AIMS

People of South Asian descent face an increased risk of Type 2 diabetes mellitus (DM) and coronary artery disease (CAD) compared with other ethnic groups. One candidate factor underlying this risk may be adiponectin, as circulating levels of this adipocyte-derived protein are reduced in both Type 2 DM and CAD. In a recent study, we assessed the relationship between adiponectin and gestational diabetes (GDM), a potential model of early events in the natural history of Type 2 DM. Here, we report the impact of ethnicity on plasma adiponectin concentration in that study.

METHODS

A cross-sectional study was performed in 180 women undergoing oral glucose tolerance testing in late second or early third trimester to investigate the relationship between adiponectin and glucose tolerance in pregnancy. Based on self-reported ethnicity, participants were stratified into three groups: (i) Caucasian (n = 116), (ii) South Asian (n = 31), and (iii) Asian (n = 28).

RESULTS

Median adiponectin concentration was much lower in the South Asian group (9.7 micro g/ml) than in Caucasians (15.8 micro g/ml) or Asians (16.1 micro g/ml) (overall P < 0.0001). With adjustment for age, prepregnancy body mass index, weight gain in pregnancy, previous history of GDM, family history of DM, fasting insulin and glucose intolerance, mean adiponectin remained significantly lower among South Asians compared with either Caucasians (P < 0.0001) or Asians (P = 0.0034).

CONCLUSIONS

Women of South Asian descent exhibit significantly reduced plasma concentrations of adiponectin in pregnancy compared with Caucasian and Asian counterparts. This observation raises the possibility of hypoadiponectinaemia as a potential factor contributing to the increased risk of diabetes and cardiovascular disease in South Asians.

Prospective multicenter study of pregnancy outcomes in women with heart disease

BACKGROUND

The maternal and neonatal risks associated with pregnancy in women with heart disease receiving comprehensive prenatal care have not been well defined.

METHODS AND RESULTS

We prospectively enrolled 562 consecutive pregnant women with heart disease and determined the outcomes of 599 pregnancies not ending in miscarriage. Pulmonary edema, arrhythmia, stroke, or cardiac death complicated 13% of pregnancies. Prior cardiac events or arrhythmia, poor functional class or cyanosis, left heart obstruction, and left ventricular systolic dysfunction independently predicted maternal cardiac complications; the cardiac event rate can be predicted using a risk index incorporating these predictors. Neonatal complications (20% of pregnancies) were associated with poor functional class or cyanosis, left heart obstruction, anticoagulation, smoking, and multiple gestations.

CONCLUSIONS

Pregnancy in women with heart disease is associated with significant cardiac and neonatal complications, despite state-of-the-art obstetric and cardiac care. Maternal cardiac risk can be predicted with the use of a risk index.

Congenital heart disease in pregnancy

Care of pregnant patients with congenital heart disease requires understanding of the specific congenital defect, the nature of previous surgical correction, and the residua and sequelae. General risks and principles can be adduced in management decisions. In addition, lesion- and patient-specific details are important. There are only a few conditions that place patients at a high enough risk to advise that pregnancy be avoided under all circumstances (pulmonary vascular obstructive disease, Marfan syndrome with dilated aortic root, severe aortic stenosis, and severe systemic ventricular dysfunction). Preconception counseling, optimization of status, and meticulous multidisciplinary management during pregnancy and the postpartum period will improve outcomes.

Obstetric outcome of adolescent pregnancies

Background: To determine if adolescent pregnancies are at increased risk of poor obstetrical outcome compared with a general obstetrical population.Methods: A five-year retrospective review of the Toronto Hospital for Sick Children's Teenage Pregnancy Unit was carried out. Information was available on 209 patients < 19 years age between January 1994 and December 1998. This was compared to information available from a database of all women delivering at the same hospital, The Toronto Hospital General Division, during the same time period (n = 13,557). The Chi-square test of independence was used to compare the data and is reported as adolescent group vs. hospital group.Results: Labour was induced in 25.5% vs. 21.8% (p = 0. 20). Epidural anaesthesia was received by 63.5% vs. 53% (p < 0.05). The incidence of preterm delivery (<37 wks) was 13.5% vs. 8.1% (p < 0.05), low-birth-weight babies (< 2500 g) 13.4% vs. 8.6% (p < 0.05) and small-for-gestational-age babies (<2 SD) 1.9%. The incidence of post-term delivery (>41 wks) was 12.5% vs. 4.3% (p < 0.001), macrosomia (>4000 g) 1.9% vs. 9.2% (p < 0.001) and large-for-gestational-age babies (>2 SD) 0.5%. Operative delivery (forceps or vacuum) occurred in 19.7% vs. 19.9% (p = 0.94) and caesarian section in 6.2% vs. 20.1% (p < 0.001). APGARs <7 at five minutes were found in 2.4% vs. 3.1% (p = 0.60). 12.0% of infants were admitted to the neonatal nursery. There were no stillbirths. Conclusions: Both preterm deliveries and low-birth-weight babies were more frequent in the adolescent group although the incidence of SGA babies was low. The low caesarian section rate also likely reflects these findings. Postterm delivery was also more common, yet macrosomia occurred less frequently.

Successful twin pregnancy in a dual-transplant couple resulting from in-vitro fertilization and intracytoplasmic sperm injection: case report

There are numerous reports of successful pregnancy following liver transplantation. Little information is available regarding the incidence and management of infertility in transplant recipients, particularly the use of artificial reproductive technologies. We present a case of a successful twin pregnancy resulting from in-vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) in a liver transplant recipient, whose partner was a renal transplant recipient with severe oligozoospermia. With careful evaluation and monitoring, and the involvement of appropriate consultants, artificial reproductive technologies can be safely used in transplant recipient couples experiencing infertility.

Prenatal detection of cerebral lesions in a fetus with tuberous sclerosis

We report a newborn, diagnosed prenatally with both cardiac rhabdomyomas and a brain tumor. To the best of our knowledge, this is the first report of central nervous system (CNS) lesions detected prenatally in a child with tuberous sclerosis with term follow-up. At 36 months, the child has normal growth and is developing appropriately. Thus the finding of CNS tumors on fetal ultrasound examination can help in the prenatal diagnosis of tuberous sclerosis but does not necessarily indicate a poor prognosis.

RhD status of a fetus at risk for haemolytic disease with a discrepant maternal DNA-based RhD genotype

The cloning of the RHD gene has made it possible to determine the RhD status of fetuses at risk for haemolytic disease due to RhD iso-immunization using amniotic fluid or chorionic villi-derived DNA and the polymerase chain reaction. However, some Rh haplotypes are associated with false-positive or negative DNA-based results with the potential for an adverse outcome. We determined the RhD status of a fetus using amniotic fluid-derived DNA for an anti-D iso-immunized woman. Initially, we obtained the ethnic background and the complete RhD and RhCcEe phenotypes of both parents. The mother was RhD negative (Cde/cde) but her DNA was positive for exon 10 of the RHD gene. The fetus was positive for both exons 4 5 and exon 10. Southern analysis confirmed that the maternal DNA contained a portion of the RHD gene with a restriction pattern that was similar to RhD-positive individuals. This report illustrates that, in addition to fetal DNA genotyping, the same PCR assays, complete with RhD and RhCcEe phenotypes, and ethnic background of the parents should be obtained to alert the molecular diagnostic laboratory to the presence of rare Rh haplotypes that are associated with DNA genotyping errors.

The Toronto Tri-Hospital Gestational Diabetes Project. A preliminary review

In this study, we assessed maternal-fetal outcomes in untreated patients with increasing carbohydrate intolerance not meeting the current criteria for the diagnosis of gestational diabetes mellitus (GDM), examined the relationship between birth weight and mode of delivery among women with untreated borderline GDM, treated overt GDM, and normoglycemia, and established more efficient screening strategies for detection of GDM. This was a prospective analytic cohort study in which nondiabetic women aged > or = 24 years were eligible for enrollment. A 50-g glucose challenge test (GCT) and a 100-g oral glucose tolerance test (OGTT) were administered at 26 and 28 weeks gestational age, respectively. Risk factors for unfavorable maternal-fetal outcomes were recorded. Time since the last meal prior to the screening test was recorded, as well. Caregivers and patients were blinded to glucose values except when test results met the National Diabetes Data Group criteria for GDM. Maternal and fetal outcomes, including the mode of the delivery, were recorded in the postpartum period. Of 4,274 patients screened, 3,836 (90%) continued to the diagnostic oral glucose tolerance test. GDM was seen in 145 women. Increasing carbohydrate intolerance in women without overt gestational diabetes was associated with a significantly increased incidence of cesarean section, preeclampsia, macrosomia, and need for phototherapy, as well as an increased length of maternal and neonatal hospital stay. Multivariate analysis showed that increasing carbohydrate intolerance remained an independent predictor for various unfavorable outcomes, but the strength of the associations was diminished. Compared with normoglycemic control subjects, the untreated borderline GDM group had increased rates of macrosomia (28.7 vs. 13.7%, P < 0.001) and cesarean delivery (29.6 vs. 20.2%, P = 0.03). Usual care of known GDM patients normalized birth weights, but the cesarean delivery rate was about 33%, whether macrosomia was present or absent. An increased risk of cesarean delivery among treated patients compared with normoglycemic control subjects persisted after adjustment for multiple maternal risk factors. As for the screening tests, time since the last meal had a marked effect on mean plasma glucose. Receiver operating characteristic curve analysis allowed the selection of the most efficient cut points for the GCT based on the time since the last meal. These cut points were 8.2, 7.9, and 8.3 mmol/l (1 mmol/l = 18.015 mg/dl) for elapsed postprandial time of < 2, 2-3, and > 3 h, respectively. With this change from the current threshold of 7.8 mmol/l, the number of patients with a positive screening test dropped from 18.5 to 13.7%. There was an increase in positive predictive value from 14.4 to 18.7%. The overall rate of patient misclassification fell from 18.0 to 13.1%. In conclusion, increasing maternal carbohydrate intolerance in pregnant women without GDM is associated with a graded increase in adverse maternal and fetal outcomes. Infant macrosomia is an important factor in high cesarean delivery rates for women with untreated borderline GDM. Although detection and treatment of GDM normalizes birth weights, rates of cesarean delivery remain inexplicably high. Recognition of GDM may lead to a lower threshold for surgical delivery. The efficiency of screening for GDM can be enhanced by adjusting the current GCT threshold of 7.8 mmol/l to new values related to time since the last meal before screening. Further analyses are underway to elucidate whether maternal risk factors can be used to achieve additional efficiency gains in screening.

Selective screening for gestational diabetes mellitus. Toronto Trihospital Gestational Diabetes Project Investigators

BACKGROUND

The usual approach to detecting gestational diabetes mellitus is to screen all pregnant women by measuring their plasma glucose after a 50-g oral glucose load at 24 to 28 weeks' gestation. Women are referred for an oral glucose-tolerance test if the plasma glucose concentration one hour later is > or = 140 mg per deciliter (7.8 mmol per liter). We hypothesized that the efficiency of screening could be enhanced by considering women's risks of gestational diabetes on the basis of their clinical characteristics.

METHODS

We studied 3131 pregnant women who underwent both the screening and the diagnostic tests. We randomly selected data on half the women and used them to derive new screening strategies. We categorized each woman's risk of gestational diabetes mellitus on the basis of her age, body-mass index before pregnancy, and race. We developed strategies that entailed no screening for low-risk women, usual care for intermediate-risk women, and universal screening with lower thresholds -- plasma glucose values of 130 mg per deciliter (7.2 mmol per liter) or 128 mg per deciliter (7.1 mmol per liter) -- for high-risk women. The strategies were validated with data on the other half of the women.

RESULTS

The new strategies allowed a 34.6 percent reduction in the number of screening tests performed (95 percent confidence interval, 32.3 to 37.0) and detected 81.2 to 82.6 percent of the women with gestational diabetes as compared with the 78.3 percent detected through usual care. The percentage of false positive screening tests was significantly reduced, from 17.9 percent with usual care to 16.0 per cent (P=0.02) or 15.4 percent (P<0.001) with the new strategies, depending on the threshold values for high-risk women.

CONCLUSIONS

Consideration of women's clinical characteristics allows efficient selective screening for gestational diabetes.

Risk and predictors for pregnancy-related complications in women with heart disease

BACKGROUND

The physiological changes of pregnancy can result in cardiovascular complications in the mother, which in turn may have fetal implications. Prior studies have focused on specific cardiac lesions or identified univariate predictors. There is a need to refine the risk stratification of women with heart disease so they can receive appropriate obstetrical counseling and care.

METHODS AND RESULTS

We examined the outcomes of 221 women with heart disease who underwent 276 pregnancies and received their obstetrical care at three Toronto hospitals from 1986 through 1994. Those who underwent therapeutic abortions were excluded. Among the study participants, there were 24 miscarriages and 252 completed pregnancies (pregnancies not ending in miscarriage). Maternal heart failure, arrhythmia, or stroke occurred in 45 completed pregnancies (18%). There were no maternal deaths. Poor maternal functional class or cyanosis, myocardial dysfunction, left heart obstruction, prior arrhythmia, and prior cardiac events were predictive of maternal cardiac complications. These predictors were incorporated into a point score that can be used to estimate the probability of a cardiac complication in the mother. The rate of cardiac complications for a patient with 0, 1, and >1 of the above factors was 3%, 30%, and 66%, respectively. Neonatal complications occurred in 42 completed pregnancies (17%). Neonatal events included death (2), respiratory distress syndrome (16), intraventricular hemorrhage (2), premature birth (35), and small-for-gestational-age birth weight (14). Poor maternal functional class or cyanosis was predictive of neonatal events.

CONCLUSIONS

Despite low maternal and neonatal mortality, pregnancy in women with heart disease is associated with significant cardiac and neonatal morbidity. The probability of maternal cardiac or neonatal events can be predicted from baseline characteristics of the mother.

Omphalocele in Miller-Dieker syndrome: expanding the phenotype

We report on a patient prenatally diagnosed with omphalocele, mild cerebral ventriculomegaly, nuchal fold thickening, and cystic changes in the umbilical cord who was found postnatally to have lissencephaly type I. Prenatal chromosome analysis showed a normal male karyotype; however, postnatal high resolution banding and FISH analysis, using a probe for locus D17S379 in chromosome region 17p13.3, demonstrated a deletion at 17p13.3 consistent with Miller-Dieker syndrome (MDS). A review documented four more cases with MDS/isolated lissencephaly/17p-, with omphalocele. Because MDS is a contiguous gene disorder, we speculate that a gene or genes in this region have a major role in the closure of the lateral folds or the return of the midgut from the body stalk to the abdomen at 5-11 weeks of gestation. Prenatal diagnosis of omphalocele with mild ventriculomegaly should prompt FISH analysis for a deletion in 17p13.3.

Systemic lupus erythematosus and pulmonary hypertension during pregnancy: report of a case fatality

The case of a 25-year-old pregnant woman with systemic lupus erythematosus and severe pulmonary hypertension is presented. The pregnancy was complicated by worsening right heart failure and pre-eclampsia, requiring a caesarian section at 29 weeks' gestation. On the fourth day postpartum, the patient's respiratory status worsened and she was transferred to the coronary care unit where she soon died from combined right heart failure and respiratory arrest. The presumed pathogenesis and etiology of lupus-related pulmonary hypertension are discussed, in addition to noninvasive tests and proposed management. Given that the mortality rate is very high during pregnancy and therapy is of limited value, women with lupus-associated pulmonary hypertension should avoid conceiving. Those who choose to become pregnant must be carefully managed by a multidisciplinary team.

Cesarean delivery in relation to birth weight and gestational glucose tolerance: pathophysiology or practice style? Toronto Trihospital Gestational Diabetes Investigators

OBJECTIVES

To examine the relationship between birth weight and mode of delivery among women with untreated borderline gestational diabetes mellitus (GDM), treated overt GDM, and normoglycemia.

DESIGN

Prospective cohort study.

SETTING

Three Toronto, Ontario teaching hospitals.

PATIENTS

A total of 3778 volunteers aged 24 years or older.

INTERVENTIONS

Subjects underwent a 3-hour long, 100-g oral glucose tolerance test at 28 weeks' gestation, regardless of screening test results. Usual care was provided to 143 women who met the National Diabetes Data Group criteria for GDM. Physicians were blinded to glucose tolerance test results for all others, including 115 untreated women with borderline GDM by the broader criteria of Carpenter and Coustan.

MAIN OUTCOME MEASURES

Crude and adjusted rates of cesarean delivery and neonatal macrosomia (birth weight >4000 g).

RESULTS

Compared with normoglycemic controls, the untreated borderline GDM group had increased rates of macrosomia (28.7% vs 13.7%, P<.001) and cesarean delivery (29.6% vs 20.2%, P=.02). Cesarean delivery in this subgroup was associated with macrosomia (45.5% vs 23.5%, P=.03). Usual care of known GDM normalized birth weights, but the cesarean delivery rate was about 33% whether macrosomia was present or absent. A clearly increased risk of cesarean delivery among treated patients compared with normoglycemic controls persisted after adjustment for multiple maternal risk factors (adjusted odds ratio, 2.1; 95% confidence interval, 1.3 to 3.6).

CONCLUSIONS

Infant macrosomia was a mediating factor in high cesarean delivery rates for women with untreated borderline GDM. While detection and treatment of GDM normalized birth weights, rates of cesarean delivery remained inexplicably high. Recognition of GDM may lead to a lower threshold for surgical delivery that mitigates the potential benefits of treatment.

Pregnancy after the fontan procedure for tricuspid atresia. A case report

BACKGROUND

Pregnancy is contraindicated in uncorrected tricuspid atresia. Even following palliative surgery with the Fontan procedure, only four pregnancies have been reported.

CASE

A 32-year-old female presented at 8 weeks' gestation in her first pregnancy with a history of the Fontan procedure performed seven years earlier for cardiac decompensation despite two previous palliative procedures for tricuspid atresia. She remained class I with no deterioration and required no medication throughout the pregnancy. Amniocentesis for positive maternal alpha-fetoprotein screening was normal. The pregnancy was complicated by antepartum hemorrhage at 29 weeks and premature rupture of membranes at 33 weeks, resulting in preterm labor and delivery of a 2.5-kg infant five days later. Apart from postpartum hemorrhage, the puerperium was uneventful, and the patient was well 20 weeks after delivery.

CONCLUSION

Five similar pregnancies, including this one, have been reported. Although all were successful, three infants were preterm and two growth retarded. This observation suggests that for these patients, pregnancy must be monitored closely even though the mothers may be hemodynamically stable.

The prognostic factors in the prenatal diagnosis of the echogenic fetal lung

The prenatal diagnosis of an echogenic fetal lung (EFL) is now often made in the early second trimester using high-resolution ultrasound. This ultrasound appearance is usually caused by a congenital cystic adenomatoid lung malformation (CCAM), an intrapulmonary lung sequestration or obstruction of a major airway. In order to provide prognostic guidelines to parents who may be considering termination of a fetus with these findings, we have analysed a series of 11 cases diagnosed in our centre over the past 2 years in conjunction with 60 cases from major published series. The data suggest that in the absence of non-immune hydrops fetalis (NIHF) or other anomalies, the outcome for the fetuses is excellent, with over 90 per cent survival. Neither early diagnosis (24 weeks) nor the presence of mediastinal shift is a poor prognostic indicator. In addition, it appears that if NIHF is absent at diagnosis, the chance that it will develop as the pregnancy continues is small (6 per cent). Furthermore, there is a significant (up to 30 per cent) chance that this ultrasound finding will resolve in utero. The development of in utero fetal surgical techniques may be the only hope for those hydropic fetuses who appear to have a dismal prognosis.

Impact of increasing carbohydrate intolerance on maternal-fetal outcomes in 3637 women without gestational diabetes. The Toronto Tri-Hospital Gestational Diabetes Project

OBJECTIVE

Our purpose was to assess maternal-fetal outcomes in patients with increasing carbohydrate intolerance not meeting the current criteria for the diagnosis of gestational diabetes.

STUDY DESIGN

We conducted a prospective analytic cohort study in which nondiabetic women aged > or = 24 years, receiving prenatal care in three Toronto teaching hospitals, were eligible for enrollment. A glucose challenge test and an oral glucose tolerance test were administered at 26 and 28 weeks' gestation, respectively; risk factors for unfavorable maternal-fetal outcomes were recorded. Caregivers and patients were blinded to glucose values except when test results met the current criteria for gestational diabetes.

RESULTS

Of 4274 patients screened, 3836 (90%) continued to the diagnostic oral glucose tolerance test. The study cohort was formed by the 3637 (95%) patients without gestational diabetes, carrying singleton fetuses. Increasing carbohydrate intolerance in women without overt gestational diabetes was associated with a significantly increased incidence of cesarean sections, preeclampsia, macrosomia, and need for phototherapy, as well as an increased length of maternal and neonatal hospital stay. Multivariate analysis showed that increasing carbohydrate intolerance is an independent predictor for various unfavorable outcomes.

CONCLUSION

Increasing maternal carbohydrate intolerance in pregnant women without gestational diabetes is associated with a graded increase in adverse maternal-fetal outcomes.

Pregnancy outcome after gestational exposure to amiodarone in Canada

OBJECTIVE

Our purpose was to quantitate the risk of perinatal thyroid dysfunction and other amiodarone-induced adverse effects among infants exposed in utero to amiodarone.

STUDY DESIGN

A historic cohort study of gestational exposure to amiodarone was conducted by contacting Canadian cardiac electrophysiologists.

RESULTS

Twelve cases were identified. Of six with first-trimester exposure, one child had congenital nystagmus with synchronous head titubation. There was one case each of transient neonatal hypothyroidism (9%) and hyperthyroidism (9%). A fourth child, exposed to amiodarone from 20 weeks' gestation, had developmental delay, hypotonia, hypertelorism, and micrognathia. Four small-for-gestational-age infants were also exposed to beta-blockers, which in addition to maternal cardiac disease, have been recognized to cause growth restriction. beta-Blockers may also have contributed to bradycardia in one of the three fetuses in whom this was observed.

CONCLUSIONS

Gestational exposure to amiodarone may be complicated by perinatal hypothyroidism or hyperthyroidism and possibly neurologic abnormalities, intrauterine growth retardation or fetal bradycardia. Concomitant beta-blocker therapy should probably be avoided. Full neonatal thyroid function tests and developmental follow-up are recommended.

Bladder pheochromocytoma in pregnancy without hypertension. A case report

A 33-year-old nullipara presented at 20 weeks' gestation with episodes of nonsustained ventricular tachycardia, which were controlled with amiodarone. No hypertension was recorded except once after an attack of ventricular tachycardia. Pheochromocytoma was suspected when repeat 24-hour urine catecholamine levels were markedly elevated. Neither computed tomography nor postpartum metaiodobenzylguanidine scan could locate the tumor. Finally it was identified in the bladder by ultrasound after selective venous sampling localized it to the pelvis. It was excised four months postpartum.

Pregnancy and functional deterioration in a woman with a univentricular heart. A case report

A patient who had undergone Pott's procedure and a right Blalock-Taussig shunt in childhood for complex cyanotic congenital heart disease with a single ventricle presented with a planned pregnancy at age 22. Although asymptomatic prior to pregnancy, she experienced functional deterioration from the first trimester and had preterm labor with a footling breech presentation at 29 weeks following prelabor rupture of the membranes. A normal, 900-g female infant was delivered by cesarean section. Despite delivery the patient continued to experience progressive functional deterioration and returned to her prepregnancy cardiac status only after a Fontan operation, performed 14 months postpartum.

Impact of time since last meal on the gestational glucose challenge test. The Toronto Tri-Hospital Gestational Diabetes Project

OBJECTIVE

The purpose of the study was to evaluate the impact of time since the last meal on the glucose challenge test and to find cut points that are most likely to predict the outcome of the oral glucose tolerance test in patients screened for gestational diabetes.

STUDY DESIGN

This prospective analytic cohort study was carried out at the University of Toronto Perinatal Complex. A 50 gm glucose load was given at 26 weeks' gestation and the time since previous meal ingestion was recorded. At 28 weeks' gestation a 100 gm oral glucose tolerance test was administered. A total of 4274 eligible patients were screened.

RESULTS

Time since the last meal had a marked effect on mean plasma glucose. Receiver-operator characteristic curve analysis with National Diabetes Data Group criteria to interpret the oral glucose tolerance allowed the selection of the most efficient cut points for the glucose challenge test on the basis of time since the last meal. These cut points were 8.2, 7.9, and 8.3 mmol/L for elapsed postprandial times of < 2, 2 to 3, and > 3 hours, respectively. With this change from the current threshold of 7.8 mmol/L the number of patients with a positive screening test dropped from 18.5% to 13.7%. There was an increase in positive predictive value from 14.4% to 18.7%. The rate of patient misclassification fell from 18.0% to 13.1%.

CONCLUSION

We suggest that screening strategies for detection of gestational diabetes be reconsidered, to account for the impact of variable postprandial status on the test results.

Pregnancy following surgical correction for transposition of the great arteries

OBJECTIVE

To determine the maternal and fetal outcomes in pregnant patients with prior surgical correction of dextro-transposition of the great arteries.

METHODS

A retrospective review was conducted of seven pregnancies managed from 1986-1992 in four women who had surgical correction for dextro-transposition of the great arteries.

RESULTS

Three of the four patients had had the Mustard operation and the other had had the Rastelli operation. There were no maternal deaths. One patient who received the Mustard operation experienced functional deterioration in the last of three pregnancies, so it was terminated. Three of the remaining six pregnancies resulted in preterm deliveries, but there was no perinatal mortality and no infants had congenital heart disease.

CONCLUSION

Maternal outcome can be satisfactory and the perinatal outcome good in patients with surgically corrected dextro-transposition of the great arteries.

Congenital aortic stenosis and pregnancy--a reappraisal

OBJECTIVE

This study was performed to determine the maternal and fetal outcome in pregnant patients with congenital aortic stenosis without previous valvular replacement.

STUDY DESIGN

A retrospective review of 25 pregnancies in 13 patients delivered at our centers from September 1976 to September 1992 was undertaken.

RESULTS

Five (38%) patients had associated congenital heart lesions, three (23%) had severe stenosis (echocardiographically estimated valve area < or = 0.7 cm2), two had prior open aortic valve commissurotomy, and one had balloon valvuloplasty during pregnancy. There were no maternal deaths. Of the 25 pregnancies, five (20%) resulted in therapeutic abortions. There was no perinatal mortality, preterm labor, or increased incidence of pregnancy complications or fetal growth retardation in the remaining 20 pregnancies. One infant (5%) had congenital heart disease.

CONCLUSION

Pregnancy outcome is generally satisfactory in patients with congenital aortic stenosis.

Management of pregnant women with cerebrospinal fluid shunts

As more women with cerebrospinal fluid shunts reach child-bearing age, neurosurgeons, obstetricians and other health care providers will increasingly be called upon to care for them once they become pregnant. A review of the literature reveals that these patients may develop symptoms of shunt malfunction as uterine size increases. In most cases, symptoms can be managed conservatively during pregnancy and usually resolve following delivery. The presence of a CSF shunt per se, is not a contraindication to pregnancy and eventual fetal and maternal outcome has been excellent in the majority of cases. Labor and delivery should be allowed to progress naturally and interventions limited to those indicated for obstetrical reasons alone. Peripartum prophylactic antibiotics may be indicated and special care ought to be exercised if epidural analgesia or cesarian section is deemed necessary. Genetic investigations and counseling may be indicated in selected patients.

Ventriculoperitoneal shunt malfunction during pregnancy

Many women with cerebrospinal fluid shunts are now reaching reproductive age. Shunt malfunction may occur during pregnancy, and management requires a well-planned, combined neurosurgical and obstetrical approach. We present a case of ventriculoperitoneal shunt obstruction manifesting during the third trimester managed successfully in a conservative fashion. The literature on ventriculoperitoneal shunt malfunction during pregnancy is reviewed.

Prenatal diagnosis and management of congenital defects of the anterior abdominal wall

Between the years 1980 and 1985, 25 cases of anterior abdominal wall defects were identified within the University of Toronto Perinatal Complex. There were 17 cases of omphalocele and eight cases of gastroschisis. Associated anomalies were found in 71% of infants with omphalocele and 50% with gastroschisis. They were the major cause of neonatal death. Prematurity was the second most common cause of death. The neonatal death rate was 59% in omphalocele and 38% in gastroschisis; the prematurity rates were 53% and 50%, respectively. In omphalocele, there was a 47% cesarean section rate, with a 50% neonatal death rate. Vaginal delivery was associated with a 67% death rate. In gastroschisis, there was a 50% cesarean section rate, with a 50% neonatal death rate. Vaginal delivery was associated with a 25% death rate. There is no evidence that cesarean section offers improved neonatal survival.

Sacrococcygeal teratoma: prenatal diagnosis and management

Although sacrococcygeal teratoma is a rare and potentially malignant tumor, 10 cases were documented during a 5-year period at the University of Toronto Perinatal Complex. Diagnosis was made in the six cases in which prenatal ultrasound examination was performed. One patient with twins elected to terminate the pregnancy at 19 weeks. In three of the cases diagnosed prenatally, serial ultrasound was performed. There was a 75% cesarean section rate. In all cases diagnosed prenatally, the large tumor size affected the mode of delivery. In the four cases without prenatal diagnosis, two infants were delivered vaginally, and two were delivered abdominally for obstetric reasons. There was one case of neonatal morbidity where tumor vascularity and rupture resulted in hypovolemic shock. All tumors were resected and found to be benign. A plan of management is recommended and, with appropriate obstetric and pediatric care, a good outcome can be anticipated in most cases.