Lucia Larson

Alveolar-arterial oxygen gradient in acute pulmonary embolism in pregnancy

OBJECTIVE Our goal was to determine the prevalence of normal alveolar-arterial gradients in pregnant patients with documented pulmonary embolism. STUDY DESIGN A retrospective chart review was performed on all pregnant women with pulmonary embolism at two large obstetric centers between 1990 and 1995. Alveolar-arterial gradients were calculated from room air arterial blood gas values and compared with values from patients who had been established as normal. RESULTS Ten of 17 patients with pulmonary embolism identified had alveolar-arterial gradients that were normal. CONCLUSIONS In our study 58% of pregnant women with documented pulmonary embolism had a normal alveolar-arterial gradient. This markedly differs from the published data in nonpregnant patients, in which the incidence of normal alveolar-arterial gradients in pulmonary embolism has ranged from 1.9% to 20%. This suggests that the alveolar-arterial gradient should not be used to determine the likelihood of pulmonary embolism in pregnant women because this could lead to the withholding of appropriate treatment for this life-threatening condition.

The incidence of deep vein thrombosis in women undergoing cesarean delivery

INTRODUCTION Venous thromboembolism (VTE) is one of the leading causes of maternal mortality in the United States. Cesarean delivery is a known risk factor. This study was to determine the incidence of deep vein thrombosis (DVT) post cesarean delivery. MATERIALS AND METHODS This was a prospective cohort study where two patients having undergone cesarean delivery each day were randomly selected. A lower extremity compression ultrasound was performed prior to hospital discharge. If no DVT was detected, participants were asked to return for a second ultrasound two weeks postpartum. Participants were also telephone-interviewed at three months for reported VTE. RESULTS Of the 194 patients who consented to study participation, only one participant developed DVT after cesarean delivery, giving an overall incidence of 0.5% (95% CI, 0.1 to 2.8%). There were no DVT identified on the second ultrasound nor VTE reported 3 months postpartum. CONCLUSIONS We found the DVT rate after cesarean delivery to be 0.5%.

Managing Asthma in Expectant Mothers

Pregnancy does not appear to have a consistent effect on the frequency or severity of asthma. The most common cause of worsening asthma in pregnancy is likely to be noncompliance with medication. Emphasizing to the patient in advance that fetal well-being is dependent on maternal well-being may help prevent this.In general, well controlled asthma is not associated with a higher risk of adverse pregnancy outcomes. Essential to successful asthma management is patient education that helps to ensure effective medication use, avoidance of triggers, and prompt treatment. This education should include measurement of peak expiratory flow rate and a written asthma action plan. Most of the medications that are used to control asthma in the general population can be safely used in pregnant women. Inhaled β-adrenoceptor agonists (β-agonists), cromolyn sodium (sodium cromoglycate), and inhaled and systemic corticosteroids all appear to be very well tolerated by the fetus. Budesonide and beclomethasone should be considered as the preferred inhaled corticosteroids for the treatment of asthma in pregnancy. Use of the leukotriene receptor antagonists zafirlukast and montelukast in pregnancy is probably safe but should be limited to special circumstances, where they are viewed essential for asthma control. Zileuton should not be used in pregnancy.Acute asthma exacerbations in pregnant women should be treated in a similar manner to that in non-pregnant patients. Maternal blood glucose levels should be monitored periodically in pregnant women receiving systemic corticosteroids because of the deleterious effects of hyperglycemia upon embryos and fetuses. During pregnancy, maternal arterial oxygen saturations should be kept above 95% if possible for fetal well-being. Ambulatory oxygenation should be checked prior to discharge to ensure that women do not desaturate with their daily activities.Acute exacerbations of asthma during labor and delivery are rare. Dinoprost, ergometrine, and other ergot derivatives can cause severe bronchospasm, especially when used in combination with general anesthesia, and should be avoided in asthmatic patients. Pregnant women who have been treated with corticosteroids in the past year may require stress-dose corticosteroids during labor and delivery. Most asthma medications, including oral prednisone, are considered compatible with breast-feeding.

Pharmacotherapy in Pregnancy and Lactation

Prescribing for patients who are pregnant and breastfeeding can be a challenge for clinicians facing insufficient information regarding medication safety, overestimation of perceived risk of medication both by patients and care providers, and increasing litigation costs. This article aims to guide the clinician in choosing the safest and most effective strategy when prescribing medications to patients who are pregnant and breastfeeding.

Childhood maltreatment and inflammation among pregnant women with gestational diabetes mellitus: A pilot study:

Background Women with childhood maltreatment histories are at increased risk for adverse birth outcomes. Mechanisms explaining this link are poorly understood. Past research is limited by sampling pregnant women at low risk for adverse maternal and neonatal outcomes. Methods This pilot study was a secondary data analysis of 24 women with gestational diabetes mellitus; 17% of the sample also reported a maltreatment history. Women provided a blood sample to measure inflammatory cytokines and insulin resistance, and saliva samples to measure diurnal cortisol. Birth outcomes for past and current pregnancies were recorded. Results Histories of maltreatment were associated with elevated interleukin-15 and a marginally greater incidence of preterm delivery in current and past pregnancies. Conclusions This pilot study was the first to demonstrate an association between childhood maltreatment history and inflammatory cytokine levels in pregnant women diagnosed with gestational diabetes mellitus.

Obstructive Sleep Apnea in Gestational Diabetes: A Pilot Study of the Role of the Hypothalamic-Pituitary-Adrenal Axis

STUDY OBJECTIVES Obstructive sleep apnea (OSA) in pregnancy is associated with gestational diabetes mellitus (GDM). This propensity toward heightened insulin resistance in OSA patients has not been well characterized and may be related to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. The aim of this study was to (1) assess the prevalence of OSA in pregnant women with GDM, (2) evaluate whether HPA axis dysregulation relates to OSA, and (3) investigate the relation between insulin resistance and OSA. We hypothesized that OSA is prevalent among pregnant women with GDM and that women with OSA will have higher levels of insulin resistance and dysregulation of the HPA axis. METHODS Twenty-five pregnant women in whom GDM was diagnosed were enrolled. Subjects answered sleep questionnaires and underwent in-home sleep studies using a level III device. The presence of OSA was defined by apnea-hypopnea index ≥ 5 events/h. Homeostasis Model Assessment of insulin resistance was derived from measurements of fasting glucose and C-peptide levels. Three salivary cortisol levels were obtained across 1 day to assess circadian variation. Multivariable linear regression analyses were used to assess associations between variables. RESULTS The sample consisted of 54% Caucasian pregnant women with a median body mass index of 36.1 and interquartile ratio of 10.6 kg/m2. OSA was diagnosed in 17% of participants. Circadian variation of cortisol was preserved in women with OSA. Women with OSA displayed blunted cortisol awakening responses. CONCLUSIONS OSA is prevalent in women with GDM. OSA is associated with preserved circadian variation and blunted cortisol awakening responses.

Diagnostic Imaging in Pregnancy

The decision to order diagnostic imaging in pregnancy is often filled with anxiety. Both the patient and provider may be fearful of the potential harmful effects of radiation on the fetus. The term radiation itself provokes images of atomic bombs and nuclear accidents. Although there is evidence that such massive doses of radiation may be associated with poor outcomes in pregnancy, it is the job of the clinician to educate women about the differences in dose and risk of radiation used in most diagnostic procedures. In many cases, diagnostic radiography is unavoidable in the evaluation and treatment of the pregnant women. In such cases, it is important to balance the potential benefits of the testing with an accurate assessment of the risk of the procedure. In short, the test is indicated when the benefits to maternal well-being outweigh the risk of harm to the mother or the fetus. While imaging with X-ray, CT, or nuclear medicine techniques are associated with exposure to ionizing radiation, almost all of these imaging studies are associated with radiation doses that are well below the acceptable limit for pregnancy. Ultrasound and MRI do not involve ionizing radiation and may provide an alternative option in some circumstances.

Placental findings associated with maternal obesity at early pregnancy.

INTRODUCTION Obesity during pregnancy is associated with a wide spectrum of maternal, fetal and neonatal complications. This study compared placental pathology in women with obesity and normal weight gravidas. MATERIALS AND METHODS This is a retrospective case-control study. The sample was randomly selected from a total of 1000 deliveries of largely Caucasian population in a single institution, recruited for the study of sleep disordered breathing, where the placenta is submitted for pathological examination for clinical indications based on national guidelines. Cases (Body mass index - BMI ≥ 30 kg/m(2); n = 47) and controls (BMI < 25 kg/m(2), n = 45) were selected based on BMI obtained from the first prenatal visit. Placental pathology, clinical parameters and limited outcomes were extracted from medical records. Placental weight range was defined as small for gestational age (SGA) if < 10th percentile, large for gestational age (LGA) if > 90th percentile. RESULTS Mean BMI was 36.2 ± 5.5 in the group with obesity and 21.7 ± 1.9 in the control group (p < 0.01). There was a significantly higher prevalence of diabetes in cases compared to controls (14/47 vs. 3/45, p = 0.006) while preterm birth was significantly higher in the control group (9/47 vs. 19/46, p = 0.02). There were more LGA placentas in cases versus controls (12/47 vs. 2/46, p = 0.007; even after adjusting for diabetes). More histological features of inflammation, marginal insertion of the umbilical cord and intervillous thrombi in the parenchyma were also noted in the case group. CONCLUSIONS Results from the current study suggest that maternal obesity measured at early pregnancy may have effects on both placental implantation and growth, and further exacerbate the hypercoagulable state in placenta.

The impact of an educational pamphlet on knowledge and anxiety in women with preeclampsia

Objective: This study was undertaken to evaluate whether or not an educational pamphlet could improve knowledge without increasing anxiety in women with preeclampsia. Methods: One hundred women recruited from an inpatient setting with suspected or proven preeclampsia were asked to answer a questionnaire assessing demographics, knowledge (primary outcome), anxiety and satisfaction (secondary outcomes) after being randomized to an intervention group (who received a pamphlet) or a control group (who did not received a pamphlet). The pamphlet and questionnaire, both designed by a multidisciplinary team, were read and answered at the same time. Results: Baseline and demographic characteristics were similar between the two groups. Knowledge about the symptoms of pre-eclampsia was excellent in both groups (61% to 100% correct answers). Women in both groups were well aware that preeclampsia in the past (P = 0.22) and a family history of preeclampsia (P = 0.57) were risk factors. There was a significant difference in knowledge about the risk of some fetal complications, including death (90% versus 39%, P < 0.01) and all maternal complications (P < 0.05) favouring the intervention group. Despite increased knowledge about preeclampsia and its risks, anxiety was not greater in the intervention group. Overall, there was a trend towards less knowledge in vulnerable subgroups (non-white, low income and schooling levels), but the improvement of knowledge with the pamphlet was equivalent. Baseline anxiety was higher in the vulnerable groups, but was generally not increased by the pamphlet. Conclusion: An educational pamphlet for women with suspected preeclampsia was able to increase knowledge without increasing anxiety.

A practical approach to using spot urine protein/creatinine ratios for assessing proteinuria in pregnancy

Objective: The aim of this study is to assess the diagnostic accuracy of the spot urine protein/creatinine ratio compared with the 24-hour urine protein in pregnancy. Study Design: In this prospective cohort study of inpatient pregnant women, the protein/creatinine ratio and dipstick protein were assessed from a single urine sample collected at the start of the 24-hour urine. Both tests were compared with the 24-hour urine protein for correlation and test characteristics. Results: In the 196 specimens analysed, we found a strong correlation between the spot urine protein/creatinine ratio and 24-hour urine protein (r 2 = 0.78, P < 0.01). A protein/creatinine ratio <0.1 ruled out significant proteinuria (≥300 mg/day) with sensitivity and negative predictive value 100%. A protein/creatinine ratio ≥0.4 detected significant proteinuria (specificity and positive predictive value of 100%). A protein/creatinine ratio ≥4.6 had a specificity and positive predictive value of 100% for detecting severe proteinuria (≥5000 mg/day). Urine dipsticks correlated poorly with the 24-hour urine protein (r 2 = 0.40, P = 0.826). Nineteen percent of dipsticks reading nil or trace were false-negative results. Conclusion: The spot urine protein/creatinine ratio correlated well with the 24-hour urine protein and performed better than the urine dipsticks. Significant proteinuria in pregnancy was excluded if the protein/creatinine ratio was <0.1 and identified when it was ≥0.4.