Calcium supplementation to prevent hypertensive disorders of pregnancy

BACKGROUND. Calcium supplementation has been reported to reduce blood pressure in pregnant and nonpregnant women. We undertook this prospective study to determine the effect of calcium supplementation on the incidence of hypertensive disorders of pregnancy (gestational hypertension and preeclampsia) and to determine the value of urinary calcium levels as a predictor of the response. METHODS. We studied 1194 nulliparous women who were in the 20th week of gestation at the beginning of the study. The women were randomly assigned to receive 2 g per day of elemental calcium in the form of calcium carbonate (593 women) or placebo (601 women). Urinary excretion of calcium and creatinine was measured before calcium supplementation was begun. The women were followed to the end of their pregnancies, and the incidence of hypertensive disorders of pregnancy was determined. RESULTS. The rates of hypertensive disorders of pregnancy were lower in the calcium group than in the placebo group (9.8 percent vs. 14.8 percent; odds ratio, 0.63; 95 percent confidence interval, 0.44 to 0.90). The risk of these disorders was lower at all times during gestation, particularly after the 28th week of gestation (P = 0.01 by life-table analysis), in the calcium group than in the placebo group, and the risk of both gestational hypertension and preeclampsia was also lower in the calcium group. Among the women who had low ratios of urinary calcium to urinary creatinine (less than or equal to 0.62 mmol per millimole) during the 20th week of gestation, those in the calcium group had a lower risk of hypertensive disorders of pregnancy (odds ratio, 0.56; 95 percent confidence interval, 0.29 to 1.09) and less of an increase in diastolic and systolic blood pressure than the placebo group. The pattern of response was similar among the women who had a high ratio of urinary calcium to urinary creatinine during the 20th week of gestation, but the differences were smaller. CONCLUSIONS. Pregnant women who receive calcium supplementation after the 20th week of pregnancy have a reduced risk of hypertensive disorders of pregnancy.     

Preterm delivery: detection of risks and preventive treatment]

Every year around the world some 13 million premature children are born. Most of these children are born in developing countries, and they account for the largest share of perinatal morbidity and mortality. This review study analyzed scientifically validated data on interventions to prevent at least some portion of these preterm deliveries and to lessen their impact on neonatal health. The Cochrane and MEDLINE bibliographic databases were consulted. Fifty review pieces and research articles were studied, relating to the following aspects of preterm delivery: risk factors and early detection of the risk of preterm delivery; preventing the risk of preterm delivery; treating preterm delivery once it has begun; and preventing neonatal respiratory distress syndrome. There were few successful approaches to the prediction, prevention, or early detection of the threat of preterm delivery. The only measures that can be recommended for all pregnant women are screening for and treating asymptomatic bacteriuria as a part of prenatal check-ups. Screening for bacterial vaginosis and treating it reduce the incidence of preterm births in pregnant women with a history of premature delivery. In addition, prophylactic cerclage decreases the incidence of premature births in pregnant women who have had more than three preterm births. To treat a delivery that starts early, with or without premature membrane rupture, the interventions that have proved to be effective are administering betamimetics to the parturient woman in order to delay delivery for 48 hours, and using indomethacin for the same purpose, as the second-choice drug. The prenatal administration of corticosteroids to the pregnant woman can induce lung maturation in the fetus and reduce respiratory distress syndrome and ventricular hemorrhage, thus decreasing neonatal mortality. There is a need to continue and support basic and epidemiological research in order to develop new knowledge on the causes and mechanisms of preterm delivery and on preventing the morbidity and mortality that preterm delivery produces.     

Corticosterone regulates both naturally occurring and cocaine‐induced dopamine signaling by selectively decreasing dopamine uptake

Stressful and aversive events promote maladaptive reward‐seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our laboratory and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine's effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast‐scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine.     

Cleavage of caspases-1, -3, -6, -8 and -9 substrates by proteases in skeletal muscles from mice undergoing cancer cachexia

A prominent feature of several type of cancer is cachexia. This syndrome causes a marked loss of lean body mass and muscle wasting, and appears to be mediated by cytokines and tumour products. There are several proteases and proteolytic pathways that could be responsible for the protein breakdown. In the present study, we investigated whether caspases are involved in the proteolytic process of skeletal muscle catabolism observed in a murine model of cancer cachexia (MAC16), in comparison with a related tumour (MAC13), which does not induce cachexia. Using specific peptide substrates, there was an increase of 54% in the proteolytic activity of caspase-1, 84% of caspase-8, 98% of caspase-3 151% to caspase-6 and 177% of caspase-9, in the gastrocnemius muscle of animals bearing the MAC16 tumour (up to 25% weight loss), in relation to muscle from animals bearing the MAC13 tumour (1-5% weight loss). The dual pattern of 89 kDa and 25 kDa fragmentation of poly (ADP-ribose) polymerase (PARP) occurred in the muscle samples from animals bearing the MAC16 tumour and with a high amount of caspase-like activity. Cytochrome c was present in the cytosolic fractions of gastrocnemius muscles from both groups of animals, suggesting that cytochrome c release from mitochondria may be involved in caspase activation. There was no evidence for DNA fragmentation into a nucleosomal ladder typical of apoptosis in the muscles of either group of mice. This data supports a role for caspases in the catabolic events in muscle involved in the cancer cachexia syndrome.     

Maternal-perinatal morbidity and mortality associated with adolescent pregnancy in Latin America: Cross-sectional study

OBJECTIVE: This study was undertaken to determine whether adolescent pregnancy is associated with increased risks of adverse pregnancy outcomes. STUDY DESIGN: We studied 854,377 Latin American women who were younger than 25 years during 1985 through 2003 using information recorded in the Perinatal Information System database of the Latin American Center for Perinatology and Human Development, Montevideo, Uruguay. Adjusted odds ratios were obtained through logistic regression analysis. RESULTS: After an adjustment for 16 major confounding factors, adolescents aged 15 years or younger had higher risks for maternal death, early neonatal death, and anemia compared with women aged 20 to 24 years. Moreover, all age groups of adolescents had higher risks for postpartum hemorrhage, puerperal endometritis, operative vaginal delivery, episiotomy, low birth weight, preterm delivery, and small-for-gestational-age infants. All adolescent mothers had lower risks for cesarean delivery, third-trimester bleeding, and gestational diabetes. CONCLUSION: In Latin America, adolescent pregnancy is independently associated with increased risks of adverse pregnancy outcomes.     

Womens' opinions on antenatal care in developing countries: results of a study in Cuba, Thailand, Saudi Arabia and Argentina

Background

The results of a qualitative study carried out in four developing countries (Cuba, Thailand, Saudi Arabia and Argentina) are presented. The study was conducted in the context of a randomised controlled trial to test the benefits of a new antenatal care protocol that reduced the number of visits to the doctor, rationalised the application of technology, and improved the provision of information to women in relation to the traditional protocol applied in each country.

Methods

Through focus groups discussions we were able to assess the concepts and expectations underlying women's evaluation of concepts and experiences of the care received in antenatal care clinics. 164 women participated in 24 focus groups discussion in all countries.

Results

Three areas are particularly addressed in this paper: a) concepts about pregnancy and health care, b) experience with health services and health providers, and c) opinions about the modified Antenatal Care (ANC) programme. In all three topics similarities were identified as well as particular opinions related to country specific social and cultural values. In general women have a positive view of the new ANC protocol, particularly regarding the information they receive. However, controversial issues emerged such as the reduction in the number of visits, particularly in Cuba where women are used to have 18 ANC visits in one pregnancy period.

Conclusion

Recommendations to improve ANC services performance are being proposed. Any country interested in the application of a new ANC protocol should regard the opinion and acceptability of women towards changes.     

Are women and providers satisfied with antenatal care? Views on a standard and a simplified,evidence-based model of care in four developing countries

BACKGROUND: This study assessed women and providers' satisfaction with a new evidence-based antenatal care (ANC) model within the WHO randomized trial conducted in four developing countries. The WHO study was a randomized controlled trial that compared a new ANC model with the standard type offered in each country. The new model of ANC emphasized actions known to be effective in improving maternal or neonatal health, excluded other interventions that have not proved to be beneficial, and improved the information component, especially alerting pregnant women to potential health problems and instructing them on appropriate responses. These activities were distributed within four antenatal care visits for women that did not need any further assessment. METHODS: Satisfaction was measured through a standardized questionnaire administered to a random sample of 1,600 pregnant women and another to all antenatal care providers. RESULTS: Most women in both arms expressed satisfaction with ANC. More women in the intervention arm were satisfied with information on labor, delivery, family planning, pregnancy complications and emergency procedures. More providers in the experimental clinics were worried about visit spacing, but more satisfied with the time spent and information provided. CONCLUSIONS: Women and providers accepted the new ANC model generally. The safety of fewer visits for women without complications with longer spacing would have to be reinforced, if such a model is to be introduced into routine practice.