Biomedical subjects

Mark Landon

Publications and source records attributed to Mark Landon.

12 recordsLinked to original sources

PubMed2006

Spirometry is related to perinatal outcomes in pregnant women with asthma.

OBJECTIVE: The purpose of this study was to test the hypothesis that maternal asthma symptoms and pulmonary function are related to adverse perinatal outcomes. STUDY DESIGN: Asthmatic patients were recruited from the 16 centers of the Maternal Fetal Medicine Units. Forced expiratory volume in 1 second was obtained at enrollment and at monthly study visits, and the frequency of asthma symptoms was assessed from enrollment to delivery. Perinatal data were obtained at postpartum chart reviews. RESULTS: The final cohort included 2123 participants with asthma. After adjustment for demographic characteristics, smoking, acute asthmatic episodes, and oral corticosteroid use, significant relationships were demonstrated between gestational hypertension and preterm birth and lower maternal gestational forced expiratory volume in 1 second. The data did not show any significant independent relationship between asthma symptom frequency and perinatal outcomes. CONCLUSION: Lower pulmonary function during pregnancy is associated with increased gestational hypertension and prematurity in the pregnancies of women with asthma, which may be due to inadequate asthma control or factors that are associated with increased asthma severity.

Adolescent↗

PubMed2006

Association of obesity with pulmonary and nonpulmonary complications of pregnancy in asthmatic women.

OBJECTIVE: To evaluate whether maternal obesity is associated with pulmonary and nonpulmonary pregnancy complications in asthmatic women. METHODS: This is a secondary analysis of the prospective cohort Asthma During Pregnancy Study. Asthma patients were classified as having either mild or moderate to severe disease at the beginning of the study. Rates of pulmonary complications of asthma in asthmatic women and rates of nonpulmonary complications of pregnancy among asthma patients and controls, were compared between obese (body mass index > or = 30 kg/m2) and nonobese women. RESULTS: Maternal body mass index and pregnancy outcome data were available for 1,699 of 1,812 asthmatic women and for 867 of 881 controls. Of the asthma subjects, 30.7% (521) were obese compared with 25.5% of the controls, P = .006. Obese women, regardless of whether they had asthma, were more likely to undergo cesarean delivery (OR 1.6, 95% confidence interval [CI]1.3-2.0) to develop preeclampsia or gestational hypertension (OR 1.7 95% CI 1.3-2.3) and gestational diabetes (OR 4.2, 95% CI 2.8-6.3). There were no differences in the rates of overall asthma improvement (20.6% compared with 23.6%, P = .36) or deterioration (33.3% compared with 28.8%, P = .20) between obese and nonobese asthma patients. After adjustment for confounding variables, obesity, not asthma, was associated with nonpulmonary complications of pregnancy, and obesity was associated with an increase in asthma exacerbations as well (OR 1.3, 95% CI 1.1-1.7). CONCLUSION: Obesity is associated with an increased risk of asthma exacerbations during pregnancy. The increased rate of nonpulmonary complications of pregnancy in asthma patients is associated with obesity in this population and not with asthma status. LEVEL OF EVIDENCE: II-1.

Adult↗

PubMed2006

Blood transfusion and cesarean delivery.

OBJECTIVE: To evaluate risks for intraoperative or postoperative packed red blood cell transfusion in women who underwent cesarean delivery. METHODS: This was a 19-university prospective observational study. All primary cesarean deliveries from January 1, 1999, to December 31, 2000, and all repeat cesareans from January 1, 1999, to December 31, 2002, were included. Trained, certified research nurses performed systematic data abstraction. Primary and repeat cesarean deliveries were analyzed separately. Univariable analyses were used to inform multivariable analyses. RESULTS: A total of 23,486 women underwent primary cesarean delivery, of whom 762 (3.2%) were transfused (median 2 units, 25th% to 75th% 2-3 units). A total of 33,683 women underwent repeat [corrected] cesarean delivery, and 735 (2.2%) were transfused (median 2 units, 25th% to 75th% 2-4 units). Among primary cesareans, general anesthesia (odds ratio [OR] 4.2, 95% confidence interval [CI] 3.5-5.0), placenta previa (OR 4.8, CI 3.5-6.5) and severe (hematocrit less than 25%) preoperative anemia (OR 17.0, CI 12.4-23.3) increased the odds of transfusion. Among repeat cesareans, the risk was increased by general anesthesia (OR 7.2, CI 5.9-8.7), a history of five or more prior cesareans (OR 7.6, CI 4.0-14.3), placenta previa (OR 15.9, CI 12.0-21.0), and severe preoperative anemia (OR 19.9, CI 14.5-27.2). CONCLUSION: Overall, the risk of transfusion in association with cesarean is low. However, both severe preoperative maternal anemia and placenta previa are associated with markedly increased risks. The former argues for optimizing maternal antenatal iron status to avoid severe anemia and the latter for careful perioperative planning when previa complicates cesarean. LEVEL OF EVIDENCE: II-2.

Anemia↗

PubMed2005

The MFMU Cesarean Registry: uterine atony after primary cesarean delivery.

OBJECTIVE: The purpose of this study was to define independent risk factors for uterine atony after primary cesarean delivery, and to assess their overall association with atony in the study cohort. STUDY DESIGN: This was a 13-university center prospective observational study. All women who underwent primary cesarean from January 1, 1999 to December 31, 2000 were eligible. Trained and certified research nurses performed systematic data abstraction. The definition of atony required both the clinical diagnosis and the use of methergine or a prostaglandin preparation. Risk factors for uterine atony were assessed in univariable and multivariable logistic regression analyses, and these analyses then used to inform an assessment of the association of the various risk factors with the occurrence of uterine atony in the overall cohort. RESULTS: Twenty-three thousand, three hundred and ninety pregnancies were analyzed. Uterine atony occurred in 1416 women (6%). Several variables were independently associated with atony in a multivariable model, including multiple gestation (odds ratio [OR] 2.40, 95% CI 1.95-2.93), maternal Hispanic race (2.21, 1.90-2.57), induced or augmented labor for >18 hours (2.23, 1.92-2.60), infant birth weight >4500 g (2.05, 1.53-2.69), and clinically diagnosed chorioamnionitis (1.80, 1.55-2.09). However, because the various risk factors were not very powerful, approximately half of the cases of atony were associated with the 2/3 of women lacking a given risk factor or combination of risk factors. CONCLUSION: Although certain risk factors and uterine atony were clearly associated, the associations are of limited practical clinical use.

Adult↗

PubMed2004

Randomized trial of inhaled beclomethasone dipropionate versus theophylline for moderate asthma during pregnancy.

OBJECTIVE: This study was undertaken to compare the efficacy of inhaled beclomethasone dipropionate to oral theophylline for the prevention of asthma exacerbation(s) requiring medical intervention. STUDY DESIGN: A prospective, double-blind, double placebo-controlled randomized clinical trial of pregnant women with moderate asthma was performed. RESULTS: There was no significant difference (P=.554) in the proportion of asthma exacerbations among the 194 women in the beclomethasone cohort (18.0%) versus the 191 in the theophylline cohort (20.4%; risk ratio [RR]=0.9, 95% CI=0.6-1.3). The beclomethasone cohort had significantly lower incidences of discontinuing study medications caused by side effects (RR=0.3, 95% CI=0.1-0.9; P=.016), and proportion of study visits with forced expiratory volume expired in 1 second (FEV1) less than 80% predicted (0.284+/-0.331 vs 0.284+/-0.221, P=.039). There were no significant differences in treatment failure, compliance, or proportion of peak expiratory flow rate less than 80% predicted. There were no significant differences in maternal or perinatal outcomes. CONCLUSION: The treatment of moderate asthma with inhaled beclomethasone versus oral theophylline resulted in similar rates of asthma exacerbations and similar obstetric and perinatal outcomes. These results favor the use of inhaled corticosteroids for moderate asthma during pregnancy because of the improved FEV1 and because theophylline had more side effects and requires serum monitoring.

Administration, Inhalation↗

PubMed2004

Is early-pregnancy proteinuria associated with an increased rate of preeclampsia in women with pregestational diabetes mellitus?

OBJECTIVE: The purpose of this study was to determine whether the rate of preeclampsia in pregnant diabetic women is increased in those women with early-pregnancy proteinuria of 190 to 499 mg/24 hours compared with women with proteinuria of <190 mg/24 hours. STUDY DESIGN: Secondary analysis was performed with relevant data from 194 pregnant women with type 1 and type 2 diabetes mellitus whose condition required insulin and who were enrolled previously in a multicenter trial of low-dose aspirin for the prevention of preeclampsia. The women were assigned to 1 of 3 groups, based on the level of proteinuria at enrollment (13-26 weeks of gestation). Group 1 comprised women with <190 mg protein/24 hours (n=94); group 2 comprised women with 190 to 499 mg protein/24 hours (n=35); and group 3 comprised women with >/=500 mg protein/24 hours (n=65). The rate of preeclampsia, according to strict predefined criteria, was then determined. RESULTS: The rate of preeclampsia was not increased statistically significantly in patients with early-pregnancy proteinuria of 190 to 499 mg/24 hours (7/35 women; 20%) when compared with women with proteinuria of <190 mg/24 hours (16/94 women; 17%). CONCLUSION: We did not find an increased rate of preeclampsia in women with pregestational diabetes mellitus with early-pregnancy proteinuria of 190 to 499 mg/24 hours when compared with women with pregestational diabetes mellitus with proteinuria of <190 mg/24 hours.

Adult↗

PubMed2004

The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes.

OBJECTIVE: The purpose of this study was to evaluate the relationship between chorioamnionitis and its duration to adverse maternal, fetal, and neonatal outcomes. STUDY DESIGN: This was a 13-university center, prospective observational study. All women at term carrying a singleton gestation who underwent primary cesarean from January 1, 1999 to December 31, 2000 were eligible. Data abstraction was systematic and performed by trained research nurses. Selected adverse outcomes were compared between pregnancies with, and without, clinically diagnosed chorioamnionitis using relative risks (RRs) and 95% CIs. The duration of chorioamnionitis was stratified into 5 intervals ( 3-6 h,>6-9 h,>9-12 h, and>12 h), and respective outcomes compared by Mantel-Haenszel test for trend. Additionally, regression analysis was used to compute odds ratios (ORs) and 95% CIs for chorioamnionitis duration length as a continuous explanatory variable. RESULTS: 16,650 pregnancies were analyzed, 1965 (12%) with chorioamnionitis, which was associated with significantly increased risks of maternal blood transfusion, uterine atony, septic pelvic thrombophlebitis, and pelvic abscess (RR 2.3-3.7), as well as 5-minute Apgar <or=3, neonatal sepsis, and seizures (RR 2.1-2.8). By test of trend, only uterine atony (P <.01), maternal blood transfusion (P=.03), maternal admission to intensive care unit (P=.02), and 5-minute Apgar <or=3 (P <.01) were associated with duration of chorioamnionitis. By logistic analysis, only uterine atony (OR for each hour of chorioamnionitis 1.03, 95% CI 1.00-1.06), 5-minute Apgar <or=3 (OR 1.09, 95% CI 1.00-1.16), and neonatal mechanical ventilation within 24 hours of birth (OR 1.07, 95% CI 1.01-1.12) were significantly associated with chorioamnionitis duration. CONCLUSION: Chorioamnionitis was associated with increased rates of morbidity after cesarean at term. The duration of chorioamnionitis, however, was not related to most measures of adverse maternal or fetal-neonatal outcome.

Adult↗

PubMed2004

The relationship of asthma medication use to perinatal outcomes.

BACKGROUND: Maternal asthma has been reported to increase the risk of preeclampsia, preterm deliveries, and lower-birth-weight infants, but the mechanisms of this effect are not defined. OBJECTIVE: We sought to evaluate the relationship between the use of contemporary asthma medications and adverse perinatal outcomes. METHODS: Asthmatic patients were recruited from the 16 centers of the National Institute of Child Health and Human Development Maternal Fetal Medicine Units Network from December 1994 through February 2000. Gestational medication use was determined on the basis of patient history at enrollment and at monthly visits during pregnancy. Perinatal data were obtained at postpartum chart reviews. Perinatal outcome variables included gestational hypertension, preterm births, low-birth-weight infants, small-for-gestational-age infants, and major malformations. RESULTS: The final cohort included 2123 asthmatic participants. No significant relationships were found between the use of inhaled beta-agonists (n=1828), inhaled corticosteroids (n=722), or theophylline (n=273) and adverse perinatal outcomes. After adjusting for demographic and asthma severity covariates, oral corticosteroid use was significantly associated with both preterm birth at less than 37 weeks' gestation (odds ratio, 1.54; 95% CI, 1.02-2.33) and low birth weight of less than 2500 g (odds ratio, 1.80; 95% CI, 1.13-2.88). CONCLUSIONS: Use of inhaled beta-agonists, inhaled steroids, and theophylline do not appear to increase perinatal risks in pregnant asthmatic women. The mechanism of the association between maternal oral corticosteroid use and prematurity remains to be determined.

Adolescent↗

PubMed2004

Asthma during pregnancy.

OBJECTIVE: To determine neonatal and maternal outcomes stratified by asthma severity during pregnancy by using the 1993 National Asthma Education Program Working Group on Asthma and Pregnancy definitions of asthma severity. The primary hypothesis was that moderate or severe asthmatics would have an increased incidence of delivery at <32 weeks of gestation compared with nonasthmatic controls. METHODS: This was a multicenter, prospective, observational cohort study conducted over 4 years at 16 university hospital centers. Asthma severity was defined according to the National Asthma Education Program Working Group on Asthma and Pregnancy classification and modified to include medication requirements. This study had 80% power to detect a 2- to 3-fold increase in delivery less than 32 weeks of gestation among the cohort with the moderate or severe asthma compared with controls. Secondary outcome measures included obstetrical and neonatal outcomes. RESULTS: The final analysis included 881 nonasthmatic controls, 873 with mild asthma, 814 with moderate, and 52 with severe asthma. There were no significant differences in the rates of preterm delivery less than 32 weeks (moderate or severe 3.0%, mild 3.4%, controls 3.3%; P =.873) or less than 37 weeks of gestation. There were no significant differences for neonatal outcomes except discharge diagnosis of neonatal sepsis among the mild group compared with controls, adjusted odds ratio 2.9, 95% confidence interval 1.2, 6.8. There were no significant differences for maternal complications except for an increase in overall cesarean delivery rate among the moderate-or-severe group compared with controls (adjusted odds ratio 1.4, 95% confidence interval 1.1, 1.8). CONCLUSION: Asthma was not associated with a significant increase in preterm delivery or other adverse perinatal outcomes other than a discharge diagnosis of neonatal sepsis. Cesarean delivery rate was increased among the cohort with moderate or severe asthma. LEVEL OF EVIDENCE: II-2

Adult↗

PubMed2003

Asthma morbidity during pregnancy can be predicted by severity classification.

BACKGROUND: The 1993 National Asthma Education Program Working Group on Asthma and Pregnancy defined asthma severity as mild, moderate, or severe on the basis of symptoms and spirometry, but no studies have evaluated the relationship between this classification system and subsequent asthma morbidity during pregnancy. OBJECTIVE: The objective of this study was to evaluate the relationship between asthma severity classification during pregnancy and gestational asthma exacerbations. METHODS: Asthma severity was defined according to the 1993 classification, adjusted to include medication requirements, in a volunteer sample of 1739 pregnant asthmatic patients who were less than 26 weeks' gestation. RESULTS: Initial asthma classification (mild, moderate, or severe) was significantly related to subsequent asthma morbidity during pregnancy (hospitalizations, unscheduled visits, corticosteroid requirements, and asthma symptoms during labor and delivery). Exacerbations during pregnancy occurred in 12.6% of patients initially classified as mild, 25.7% of patients classified as moderate, and 51.9% of patients classified as severe (P <.001). Asthma morbidity was similar, whether patients were classified as moderate or severe by symptoms and spirometry or by medication requirement. Thirty percent of initially mild patients were reclassified as moderate-severe during pregnancy, and 23% of the initially moderate-severe patients were reclassified as mild later in pregnancy; asthma morbidity in these patients changed accordingly. CONCLUSION: The National Asthma Education Program Working Group on Asthma and Pregnancy classification of asthma severity, adapted to include medication use, predicts subsequent asthma morbidity during pregnancy.

Adult↗

PubMed2002

Adverse perinatal outcomes are significantly higher in severe gestational hypertension than in mild preeclampsia.

OBJECTIVE: The current literature emphasizes increased risk of adverse outcomes in the presence of proteinuria and hypertension. The objective of this study was to compare the frequency of adverse fetal outcomes in women who developed hypertensive disorders with or without proteinuria. STUDY DESIGN: The study design was a secondary analysis of data from women who had preeclampsia in a previous pregnancy (n = 598) who were enrolled in a multicenter trial of aspirin for the prevention of preeclampsia. The women had no history of chronic hypertension or renal disease and were normotensive at study inclusion. The maternal and perinatal outcome variables assessed were preterm delivery at <37 and <35 weeks of gestation, rate of small-for-gestational-age infants, and abruptio placenta. Data were analyzed by using the chi-square test, and women who remained normotensive or who had mild gestational hypertension were considered as a single group because they had similar outcomes. RESULTS: As compared to mild preeclampsia, women who developed severe gestational hypertension (without proteinuria) had higher rates of both preterm delivery at <37 weeks of gestation and small-for-gestational-age infants. In addition, when compared to women with mild preeclampsia, for women with severe gestational hypertension, gestational age and birth weight were significantly lower at delivery (P <.003 for both age and birth weight). Moreover, women who developed severe gestational hypertension had higher rates of preterm delivery at <37 weeks of gestation (54.2% vs 17.8%, P =.001) and at <35 weeks of gestation (25.0% vs 8.4%, P =.0161), and delivery of small-for-gestational-age infants (20.8% vs 6.5%, P =.024) when compared to women who remained normotensive or those who developed mild gestational hypertension. There were no statistically significant differences in perinatal outcomes between the normotensive/mild gestational hypertension and the mild preeclampsia groups. Overall, women who had severe gestational hypertension had increased rates of preterm delivery and delivery of small-for-gestational-age infants than women with mild gestational hypertension or mild preeclampsia. In the presence of severe hypertension, proteinuria did not increase the rates of preterm delivery or delivery of small-for-gestational-age infants. CONCLUSIONS: In women who have gestational hypertension or preeclampsia, increased rates of preterm delivery and delivery of small-for-gestational-age infants are present only in those with severe hypertension. In these women, the presence of proteinuria does not influence perinatal outcome.

Adult↗

PubMed2002

Perinatal outcome in women with recurrent preeclampsia compared with women who develop preeclampsia as nulliparas.

OBJECTIVE: To compare the rates and perinatal outcome in women who experienced preeclampsia in a previous pregnancy to those in women who developed preeclampsia as nulliparas. STUDY DESIGN: This is a secondary analysis of data from 2 separate multi-center trials of aspirin for prevention of preeclampsia. Women who had preeclampsia in a previous pregnancy (n = 598) were compared with nulliparous women (n = 2934). Outcome variables were rates of preeclampsia, preterm delivery at <37 and <35 weeks of gestation, small-for-gestational-age infant, abruptio placentae, and perinatal death. Data were compared by using chi-square analysis and Wilcoxon rank sum test. RESULTS: The rates of preeclampsia and of severe preeclampsia were significantly higher in the previous preeclamptic group as compared to the nulliparous group (17.9% vs 5.3%, P <.0001, and 7.5% vs. 2.4%, P <.0001, respectively). Women who had recurrent preeclampsia experienced more preterm deliveries before 37 and 35 weeks of gestation than nulliparous women who developed preeclampsia. In addition, among women who developed severe preeclampsia, those with recurrent preeclampsia had higher rates of preterm delivery both before 37 weeks (67% vs 33%, P =.0004) and before 35 weeks of gestation (36% vs 19%, P =.041), and higher rates of abruptio placentae (6.7% vs 1.5%) and fetal death (6.7% vs 1.4%) than did nulliparous women. CONCLUSION: Compared to nulliparous women, women with preeclampsia in a previous pregnancy had significantly higher rates of preeclampsia and adverse perinatal outcomes associated with preterm delivery as a result of preeclampsia.

Abruptio Placentae↗