Search PubMed⌕ Search

Biomedical subjects

M S Kramer

Publications and source records attributed to M S Kramer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Impact of prenatal glucose screening on the diagnosis of gestational diabetes and on pregnancy outcomes.

The authors examined the impact of universal screening on the diagnosis of gestational diabetes and its complications. All mothers and newborns registered by the Canadian Institute for Health Information from 1984 to 1996 (even-numbered fiscal years only) were included in the analysis. Over this time period, the proportion of women with gestational diabetes increased ninefold (from 0.3% to 2.7%) while the proportion with prepregnancy diabetes fell from 0.7% to 0.4%. As rates of gestational diabetes increased, a corresponding reduction in the risks of complications (polyhydramnios, amniotic cavity infection, cesarean delivery, and preeclampsia) occurred for women with gestational diabetes. The incidence of gestational diabetes fell in Metro-Hamilton (where screening was discontinued in 1989) but remained high in the rest of Ontario (where screening continued in most areas). No related temporal trends for fetal macrosomia, cesarean delivery, or other diabetes-related complications were observed, regardless of screening policy. The authors concluded that the substantial increase in gestational diabetes in Canada is an artifact caused by universal screening, with no evidence of beneficial effects on pregnancy outcomes.

Blood Glucose↗
PubMed2000

Within-patient consistency of response of rizatriptan for treating migraine.

OBJECTIVE: To determine the within-patient consistency of response for rizatriptan, a 5-HT(1B/1D) receptor agonist for the acute treatment of migraine. METHODS: Post hoc analysis was performed on data from a randomized, double-blind, placebo-controlled clinical trial. Four hundred seventy-three patients with migraine diagnosed according to the criteria of the International Headache Society were randomly assigned to one of five sequence groups in which each patient was scheduled to treat four separate moderate or severe migraine attacks. Patients in four groups received 10 mg of rizatriptan for three of four attacks and placebo for the remaining attack; patients in the fifth group received 10 mg of rizatriptan for all four attacks. Headache severity, functional disability, and associated migraine symptoms were measured immediately before dosing and at regular intervals up to 4 hours after the dose. The analysis was based on efficacy at 2 hours after dosing, the last time point before escape medications were allowed. The percentages of patients who responded in a specified number of attacks after treatment with rizatriptan were calculated. The analysis was descriptive, and no formal statistical testing was performed. RESULTS: Of the evaluable patients who treated three migraine attacks with 10 mg of rizatriptan (with an additional interspersed placebo-treated attack in most patients), 216 of 252 (86%) had pain relief (reduction of pain to mild or none), 122 of 252 (48%) were pain free, 211 of 250 (84%) had no nausea, 163 of 251 (65%) had no photophobia, 182 of 252 (72%) had no phonophobia, 136 of 249 (55%) had no functional disability, and 233 of 252 (92%) had no need for escape medications at 2 hours after dosing in at least two of three attacks. CONCLUSION: The response to 10 mg of oral rizatriptan within individual patients was consistent over three attacks on a range of measures.

Adolescent↗
PubMed2000

The contribution of mild and moderate preterm birth to infant mortality. Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System.

CONTEXT: The World Health Organization defines preterm birth as birth at less than 37 completed gestational weeks, but most studies have focused on very preterm infants (birth at <32 weeks) because of their high risk of mortality and serious morbidity. However, infants born at 32 through 36 weeks are more common and their public health impact has not been well studied. OBJECTIVE: To assess the quantitative contribution of mild (birth at 34-36 gestational weeks) and moderate (birth at 32-33 gestational weeks) preterm birth to infant mortality. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study using linked singleton live birth-infant death cohort files for US birth cohorts for 1985 and 1995 and Canadian birth cohorts (excluding Ontario) for 1985-1987 and 1992-1994. MAIN OUTCOME MEASURES: Relative risks (RRs) and etiologic fractions (EFs) for overall and cause-specific early neonatal (age 0-6 days), late neonatal (age 7-27 days), postneonatal (age 28-364 days), and total infant death among mild and moderate preterm births vs term births (at >/=37 gestational weeks). RESULTS: Relative risks for infant death from all causes among singletons born at 32 through 33 gestational weeks were 6.6 (95% confidence interval [CI], 6.1-7.0) in the United States in 1995 and 15.2 (95% CI, 13.2-17.5) in Canada in 1992-1994; among singletons born at 34 through 36 gestational weeks, the RRs were 2.9 (95% CI, 2.8-3.0) and 4.5 (95% CI, 4.0-5.0), respectively. Corresponding EFs were 3.2% and 4.8%, respectively, at 32 through 33 gestational weeks and 6.3% and 8.0%, respectively, at 34 through 36 gestational weeks; the sum of the EFs for births at 32 through 33 and 34 through 36 gestational weeks exceeded those for births at 28 through 31 gestational weeks. Substantial RRs were observed overall for the neonatal (eg, for early neonatal deaths, 14.6 and 33.0 for US and Canadian infants, respectively, born at 32-33 gestational weeks; EFs, 3.6% and and 6. 2% for US and Canadian infants, respectively) and postneonatal (RRs, 2.1-3.8 and 3.0-7.0 for US and Canadian infants, respectively, born at 32-36 gestational weeks; EFs, 2.7%-5.8% and 3.0%-7.0% for the same groups, respectively) periods and for death due to asphyxia, infection, sudden infant death syndrome, and external causes. Except for a reduction in the RR and EF for neonatal mortality due to infection, the patterns have changed little since 1985 in either country. CONCLUSIONS: Mild- and moderate-preterm birth infants are at high RR for death during infancy and are responsible for an important fraction of infant deaths. JAMA. 2000;284:843-849

Canada↗
PubMed2000

Balanced protein/energy supplementation in pregnancy.

BACKGROUND: Observational and non-randomized studies have suggested that energy/protein supplementation in pregnant women increases gestational weight gain and fetal growth. OBJECTIVES: The objective of this review was to assess the effects of a balanced protein/energy supplement for pregnant women on gestational weight gain and on the outcome of pregnancy. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched. Date of last search: January 2000. SELECTION CRITERIA: Acceptably controlled trials of energy/protein supplementation for pregnant women in which the protein content of the supplement was 'balanced' (protein content less than 25% of total energy content). DATA COLLECTION AND ANALYSIS: One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Thirteen trials were included. They were of variable quality. Balanced protein/energy supplementation was associated with modest increases in maternal weight gain (weighted mean difference 17 grams per week, 95% confidence interval 5-29 grams per week) and fetal growth (birth weight increase, weighted mean difference 25 grams, 95% confidence interval 4-55 grams). The reduction in risk of small for gestational birth was substantial, however (odds ratio 0. 64, 95% confidence interval 0.53-0.78). These effects did not appear to be greater in undernourished women, nor did they seem to confer long term benefits to the child. No significant effects were detected on preterm birth, but significant reductions in stillbirth and neonatal death (based on only 3 trials) appear important. REVIEWER'S CONCLUSIONS: Balanced energy/protein supplementation improves fetal growth and may reduce the risk of fetal and neonatal death. The evidence is insufficient to evaluate whether there are other potential benefits to pregnant women or their infants.

Dietary Supplements↗
PubMed2000

Energy/protein restriction for high weight-for-height or weight gain during pregnancy.

OBJECTIVES: To assess the effects of prescribing a low-energy diet to pregnant women who are either overweight, or who exhibited high weight gain earlier in gestation, on subsequent weight gain, pre-eclampsia, and the outcome of pregnancy. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched and researchers in the field were contacted. SELECTION CRITERIA: All acceptably controlled comparisons of protein/energy restriction prescribed to pregnant women who meet one or both of the criteria listed above. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Three studies involving 266 women were involved. Energy/protein restriction leads to a significant reduction in weekly maternal weight gain and in birth weight but has no clear effect on either pregnancy-induced hypertension or pre-eclampsia. Other outcomes, including fetal/infant mortality and other measures of maternal morbidity (eg Caesarean section) or long-term nutritional status, have not been reported. REVIEWER'S CONCLUSIONS: Protein/energy restriction of pregnant women who are overweight or exhibit high weight gain is unlikely to be beneficial and may be harmful to the developing fetus.

Diet↗
PubMed2000

High protein supplementation in pregnancy.

OBJECTIVES: To assess the effects of providing pregnant women with high-protein nutritional supplements on gestational weight gain and on the outcome of pregnancy, including fetal growth, gestational duration, and maternal and fetal/infant morbidity and mortality. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of protein/energy supplementation in which the protein content of the supplement provided >25% of its total energy content. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Two studies involving 1076 women were included. High protein supplementation was associated with a small, statistically nonsignificant increase in weekly maternal weight gain. The two available trials provide no evidence of benefit on fetal growth; indeed, the adjusted mean difference in birth weight is -58. 4 g. One trial also reported a nonsignificantly increased risk of neonatal death with high-protein supplementation. REVIEWER'S CONCLUSIONS: There is not enough evidence to evaluate the use of high protein supplementation in pregnancy.

Dietary Proteins↗
PubMed2000

Isocaloric balanced protein supplementation in pregnancy.

OBJECTIVES: To assess the effects of providing pregnant women with isocaloric protein supplements (ie where the protein replaces an equal quantity of nonprotein energy) on gestational weight gain and on the outcome of pregnancy. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of isocaloric protein supplementation, as long as the protein content of the supplement was 'balanced', ie the protein provided <25% of its total energy content. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Three trials involving 966 women were included. The results suggest a decrease in maternal weight gain and mean birth weight and an increased risk of small-for-gestational-age (SGA) births with isocaloric protein supplementation, but no effect on mean gestational age or preterm birth. The data are insufficient to exclude potentially important effects on fetal or neonatal mortality, and maternal health outcomes have not been reported. REVIEWER'S CONCLUSIONS: Balanced protein supplementation alone (ie without energy supplementation) is unlikely to be of benefit to pregnant women or their infants.

Dietary Proteins↗
PubMed2000

Maternal antigen avoidance during lactation for preventing atopic eczema in infants.

OBJECTIVES: To assess the effects of prescribing an antigen avoidance diet to lactating mothers of infants with atopic eczema on the severity of the eczema. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of maternal antigen avoidance prescribed to lactating mothers of infants with atopic eczema, regardless of the degree of antigen avoidance (number of foods eliminated from the diet) or its duration. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: One trial involving 17 women was included. Based on this single small trial, maternal antigen avoidance was associated with a nonsignificant reduction in eczema severity. REVIEWER'S CONCLUSIONS: The unimpressive results of this single trial should be interpreted with caution both because of its small size (n=17) and because the trial compared exposure to cow milk and egg with exposure to soya milk (soya can itself be allergenic). Maternal reports of changes in the severity of their breast-fed infants' eczema following ingestion of certain foods should be pursued by performing multiple (preferably double-blinded) challenges and dechallenges with the suspected foods.

Dermatitis, Atopic↗
PubMed2000

Maternal antigen avoidance during lactation for preventing atopic disease in infants of women at high risk.

OBJECTIVES: To assess the effects of prescribing an antigen avoidance diet during lactation on the nutritional status of the mother and newborn and on the development of atopic disease in the child. The main focus is on women whose infants are at high risk for developing an atopic condition, based on a history of atopic disease in the mother, father, or a previous child. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of maternal antigen avoidance prescribed to lactating women at high risk, regardless of the degree of antigen avoidance (number of foods eliminated from the diet) or its duration. Trials of multimodal interventions that include manipulation of the infant's diet other than breast milk or of other nondietary aspects of the infant's environment (eg, exposure to inhaled allergens) have been excluded from the review. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Three trials involving 209 women were included. The combined data from the three available trials suggest a strong protective effect of maternal antigen avoidance on the incidence of atopic eczema during the child's first 12-18 months of life. Methodologic shortcomings in all three trials, however, argue for caution in applying these encouraging results. In particular, the high incidence of atopic eczema in the control groups of all three trials might be explained by nonblinding or de-blinding of the examining physicians. REVIEWER'S CONCLUSIONS: Prescription of an antigen avoidance diet to a high-risk woman during lactation may substantially reduce her child's risk of developing atopic eczema, but better trials are needed.

Dietary Proteins↗
PubMed2000

Maternal antigen avoidance during pregnancy for preventing atopic disease in infants of women at high risk.

OBJECTIVES: To assess the effects of prescribing an antigen avoidance diet during pregnancy on the nutritional status of the mother and newborn and on the development of atopic disease in the child. The main focus is on women at high risk for giving birth to an atopic child, based on a history of atopic disease in the mother, father, or a previous child. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of maternal antigen avoidance prescribed to pregnant women at high risk, regardless of the degree of antigen avoidance (number of foods eliminated from the diet) or the time of its onset during pregnancy. Data are also included on formula-fed (ie non-breastfed) infants in trials of maternal antigen avoidance intended to continue beyond pregnancy into the lactation period. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Three trials involving 504 women were included. Based on the single trial providing pertinent data, the restricted diet was associated with a small but statistically significant lower mean gestational weight gain (mean difference = -3.0% of prepregnancy weight) and a nonsignificantly higher risk of preterm birth. The combined evidence does not suggest a strong protective effect of maternal antigen avoidance on the incidence of atopic eczema or asthma during the first 12-18 months of life. Data on allergic rhinitis/conjuctivitis and urticaria are limited to a single trial each and are insufficient to draw meaningful inferences. Two trials suggest a lower incidence of skin prick tests to egg at 6 months of age, but the effect was no longer evident at 18 months, nor was any benefit apparent at either age for skin prick tests to milk. If anything, cord blood IgE levels were higher in the experimental (antigen avoidance) group. REVIEWER'S CONCLUSIONS: Prescription of an antigen avoidance diet to a high-risk woman during pregnancy is unlikely to reduce substantially her risk of giving birth to an atopic child. Moreover, such a diet may have an adverse effect on maternal and/or fetal nutrition.

Dietary Proteins↗
PubMed2000

Nutritional advice in pregnancy.

OBJECTIVES: To assess the effects of advising pregnant women to increase their energy and protein intakes on those intakes, on gestational weight gain, and on the outcome of pregnancy. SEARCH STRATEGY: The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group. SELECTION CRITERIA: All acceptably controlled comparisons of nutritional advice, whether administered on a one-to-one basis or to groups of women. DATA COLLECTION AND ANALYSIS: Data were extracted by the author from published reports, and supplemented by additional information from trialists contacted by the author. MAIN RESULTS: Four trials involving 1108 women were included. Advice to increase energy and protein intakes seems to be successful in achieving those goals, but the increases are lower than those reported in trials of actual protein/energy supplementation. Data concerning effects on pregnancy outcome are available only from one trial, and, given the fact that its analysis was based on individual women despite randomization by clinic, the calculated confidence intervals are undoubtedly too narrow. Moreover, the 'significant' reduction in preterm birth associated with advice is not consistent with the total absence of effect on mean gestational age. One trial found no reduction in the incidence of pre-eclampsia. No data have been reported on potential adverse effects that might accompany increased fetal size, such as an increased risk of prolonged labour or Caesarean section. REVIEWER'S CONCLUSIONS: Nutritional advice appears effective in increasing pregnant women's energy and protein intakes, but the implications for fetal, infant, or maternal health cannot be judged from the available trials. Given the rather modest health benefits demonstrated with actual protein/energy supplementation (see the Cochrane review of 'Balanced protein/energy supplementation in pregnancy'), however, the provision of such advice is unlikely to be of major importance.

Female↗
PubMed2000

Regular aerobic exercise during pregnancy.

BACKGROUND: Physiological responses of the fetus (especially increase in heart rate) to single, brief bouts of maternal exercise have been documented frequently. OBJECTIVES: The objective of this review was to assess the effects of advising healthy pregnant women to engage in regular (at least two to three times per week) aerobic exercise on physical fitness, labour and delivery, and the outcome of pregnancy. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched. SELECTION CRITERIA: Acceptably controlled comparisons of prescribed aerobic exercise programmes. DATA COLLECTION AND ANALYSIS: One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information. MAIN RESULTS: Five trials involving 142 women were included. The trials were not of high methodologic quality. Three trials reported significant improvement in physical fitness in the exercise group, although differences in measures used to assess fetuses prevent a quantitative pooling of results. Two small trials reported nonsignificant results on pregnancy outcomes, but apart from a reassurring absence of effect on mean gestational age [+0.3 (-0.2 to +0.9) weeks], these results allow exclusion of only extremely large effects. REVIEWER'S CONCLUSIONS: Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness. Available data are insufficient to exclude important risks or benefits for the mother or infant.

Exercise↗
PubMed2000

Determinants of unexplained antepartum fetal deaths.

OBJECTIVE: To assess fetal, maternal, and pregnancy-related determinants of unexplained antepartum fetal death. METHODS: We conducted a hospital-based cohort study of 84,294 births weighing 500 g or more from 1961-1974 and 1978-1996. Unexplained fetal deaths were defined as fetal deaths occurring before labor without evidence of significant fetal, maternal, or placental pathology. RESULTS: One hundred ninety-six unexplained antepartum fetal deaths accounted for 27.2% of 721 total fetal deaths. Two thirds of the unexplained fetal deaths occurred after 35 weeks' gestation. The following factors were independently associated with unexplained fetal death: maternal prepregnancy weight greater than 68 kg (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI] 1.85, 4.68), birth weight ratio (defined as ratio of birth weight to mean weight for gestational age) between 0.75 and 0.85 (OR 2.77; 95% CI 1.48, 5.18) or over 1.15 (OR 2.36; 95% CI 1.26, 4.44), fewer than four antenatal visits in women whose fetuses died at 37 weeks or later (OR 2.21; 95% CI 1.08, 4.52), primiparity (OR 1.74; 95% CI 1.26, 2.40), parity of three or more (OR 2.01; 95% CI 1.26, 3.20), low socioeconomic status (OR 1.59; 95% CI 1.14, 2.22), cord loops (OR 1.75; 95% CI 1.04, 2.97) and, for the 1978-1996 period only, maternal age 40 years or more (OR 3.69; 95% CI 1.28, 10.58). Trimester of first antenatal visit, low maternal weight, postdate pregnancy, fetal-to-placental weight ratio, fetal sex, previous fetal death, previous abortion, cigarette smoking, and alcohol use were not significantly associated with unexplained fetal death. CONCLUSION: In this study, we identified several factors associated with an increased risk of unexplained fetal death.

Adult↗
PubMed2000

Socio-economic disparities in pregnancy outcome: why do the poor fare so poorly?

In this paper, we review the evidence bearing on socio-economic disparities in pregnancy outcome, focusing on aetiological factors mediating the disparities in intrauterine growth restriction (IUGR) and preterm birth. We first summarise what is known about the attributable determinants of IUGR and preterm birth, emphasising their quantitative contributions (aetiological fractions) from a public health perspective. We then review studies relating these determinants to socio-economic status and, combined with the evidence about their aetiological fractions, reach some tentative conclusions about their roles as mediators of the socio-economic disparities. Cigarette smoking during pregnancy appears to be the most important mediating factor for IUGR, with low gestational weight gain and short stature also playing substantial roles. For preterm birth, socio-economic gradients in bacterial vaginosis and cigarette smoking appear to explain some of the socio-economic disparities; psychosocial factors may prove even more important, but their aetiological links with preterm birth require further clarification. Research that identifies and quantifies the causal pathways and mechanisms whereby social disadvantage leads to higher risks of IUGR and preterm birth may eventually help to reduce current disparities and improve pregnancy outcome across the entire socio-economic spectrum.

Canada↗
PubMed2000

Placenta praevia and male sex at birth: results from a population-based study.

This study examined the relationship between male sex at birth and placenta praevia in 433031 mother/infant dyads (linked by a common institutional code and hospital admission number) in the Canadian province of Quebec, during the fiscal years of 1991/92-1995/96. The male-to-female ratio among pregnancies with and without placenta praevia was calculated and compared. The male-to-female ratio at birth was higher in pregnancies complicated by a placenta praevia (1.19) than in those without it (1.04; P < 0.02). This increased ratio persisted after accounting separately for the potential confounding and/or modifying effects of maternal age, infant birthweight and gestational age by stratified and multiple logistic regression analyses. We conclude that pregnant women with male babies carry a higher risk of placenta praevia.

Birth Weight↗
PubMed2000

Gestational age- and birthweight-specific declines in infant mortality in Canada, 1985-94. Fetal and Infant Health Study Group of the Canadian Perinatal Surveillance System.

We studied infant mortality rates in Canada within specific gestational age and birthweight categories after using probabilistic techniques to link information in Statistics Canada's live births data base (1985-94) with that in the death data base (1985-95). Gestational age- and birthweight-specific mortality rates in 1992-94 were contrasted with those in 1985-87 with changes expressed in terms of relative risks with 95% confidence intervals [CI]. Statistically significant reductions in infant mortality were observed beginning at 24-25 weeks of gestation and extended across the gestational age range to post-term births. Crude infant mortality rates, infant mortality rates among those > or = 500 g and among those > or = 1000 g decreased by 22%, 25% and 26%, respectively, from 1985-87 to 1992-94. The magnitude of the reductions in infant mortality rates ranged from 14% [95% CI 7, 21%] at 24-25 weeks of gestation to 40% [95% CI 31, 47%] at 28-31 weeks. Almost all reductions in gestational age- and birthweight-specific infant mortality between 1985-87 and 1992-94 were due to approximately equal reductions in neonatal and post-neonatal mortality. Live births > or = 42 weeks of gestation did not follow this rule; post-neonatal mortality rates among such live births decreased significantly by 51% [95% CI 26, 68%], although neonatal mortality rates showed no significant change. The mortality reductions observed across the gestational age and birthweight range are probably a consequence of specific clinical interventions complementing improvements in fetal growth. Temporal changes in the outcome of post-term pregnancies need to be carefully examined, especially in relation to recent changes in the obstetric management of such pregnancies.

Adult↗