Calciuria and preeclampsia: a case-control study

AIM

Calciuria has been reported to decrease in preeclampsia. We compared calciuria among groups of normal, hypertensive and preeclamptic pregnant women, and assessed its correlation with the severity of the disease.

MATERIAL AND METHODS

We conducted a case-control study of mild and severe preeclampsia, chronic hypertension, and normal pregnancy, with 14 patients in each group. The groups were analyzed by one-way anova (variance analysis) for symmetrical distribution and Kruskal-Wallis test for asymmetrical distribution when comparing quantitative variables, and by crossed tables when comparing qualitative variables.

RESULTS

There were statistically significant differences between the groups when comparing severe preeclampsia with chronic hypertension, and severe preeclampsia with the control group (P < 0.0001). The calciuria medians were 81.5 mg/24 h for severe preeclampsia, 118 mg/24 h for mild preeclampsia, 226 mg/24 h for chronic hypertension, and 272 mg/24 h for the control group. In a ROC (receiver operating characteristic) curve analysis, the best cutoff point for preeclampsia diagnosis was 167 mg/24 h, with a sensitivity of 75% and a specificity of 85%. The outcomes were more severe as the level of calciuria dropped.

CONCLUSION

Measurement of calciuria can differentiate between severe preeclampsia and chronic hypertension, and hypocalciuria is also a marker for disease severity.

Variation in the Urinary Protein/Creatinine Ratio at Four Different Periods of the Day in Hypertensive Pregnant Women

OBJECTIVE

To assess the urine protein/creatinine ratio in urine samples of pregnant women with hypertension in regard to: 1) the presence of significant variation at different periods of the day; 2) the differences if they exist, to identify the most reliable period of the day for sampling; and 3) whether the first sample, obtained when the patient arrives at the clinic, correlates with the same accuracy, with the 24-hour proteinuria.

DESIGN

Cross-sectional study.

PLACE

Obstetrics Emergency Department, Hospital de Clínicas de Porto Alegre, a teaching hospital in Porto Alegre, Brazil.

POPULATION

Seventy-five women with hypertension with 20-week gestation or over.

METHODS

Urine samples for determination of the protein/creatinine ratio were obtained on arrival (first specimen) and every 6 hours thereafter, totaling four samples in 24 hours. Four sampling periods were established: 1) from 8 am to 2 pm, 2) from 2 pm to 8 pm, 3) from 8 pm to 2 am, and 4) from 2 am to 8 am. The protein/creatinine ratio in the four different day periods were compared with the 24-hour proteinuria obtained simultaneously. The results were analyzed by the Spearman correlation and the receiver-operator characteristic (ROC) curve.

RESULTS

The urine protein/creatinine ratio is strongly correlated (Spearman correlation equal to 0.8 or greater) with the 24-hour proteinuria at all four periods of the day (p<0.001), as well as the first sample obtained on arrival (p=0.003). These findings were corroborated by the ROC curve in which the values of four day periods and that of the first sample were equal to or greater than 0.930.

CONCLUSION

In hypertensive pregnant women, the single voided urine sample protein/creatinine ratio, irrespective of sampling time, is strongly correlated with the 24-hour proteinuria, as is the sample obtained on arrival.

Reported calcium intake is reduced in women with preeclampsia

OBJECTIVE

The purpose of this trial is to investigate the relationship between dietary calcium content and incidence of preeclampsia, comparing diet calcium content in normotensive and preeclampsia patients. Dietary calcium was measured by a dietary interview conducted at the day after delivery.

METHODS

This is a prospective cross-sectional study involving 1092 patients who delivered at Hospital de Clínicas de Porto Alegre - Brazil.

RESULTS

The average diet calcium content in the studied population was 1038 mg. The average calcium intake in the normotensive group was 1057 mg, in chronic hypertension group was 962 mg, in transient hypertension group was 963 mg, in mild preeclampsia was 902 mg and in severe preeclampsia group was 755 mg. The results of this study show that pregnant women who develop severe preeclampsia have a significant lower diet calcium intake when compared to normotensive women (P = 0.018).

CONCLUSION

The results of the present study can provide the foundations for prospective trials, including randomised clinical trials involving only patients with a low content of calcium in their diet.

Transvaginal ultrasonographic assessment of the expulsion rate of intrauterine devices inserted in the immediate postpartum period: a pilot study

OBJECTIVE

To compare the expulsion rates of intrauterine devices (IUDs) inserted in the immediate postpartum after vaginal birth and cesarean section.

METHODS

Nineteen patients who had a vaginal birth and 19 patients who had a cesarean section at Hospital de Clínicas de Porto Alegre, Brazil, were selected for copper T 380A IUD insertion. With the aim of detecting clinically unnoticed dislodged devices, ultrasound examinations were performed at 1 month and between 3 and 12 months after delivery. The IUDs were considered completely expelled when found outside the endometrial cavity (e.g., in the cervical canal) or outside the uterus (in the vagina).

RESULTS

Expulsion rates were statistically different between the two groups: after a vaginal birth, 50% (ultrasound only) + 27.8% (clinical examination); and post-cesarean section, 0% (p < .001; OR 5.75, 95% CI 2.36-14.01).

CONCLUSION

Considering that the contraceptive efficacy of IUDs is associated with their intrauterine location, the high expulsion rates seen when they are inserted immediately after vaginal delivery contraindicate their use in this setting. The use of IUDs immediately after a cesarean section is still a reasonable alternative because its expulsion rate was zero. Ultrasound assessment of IUD positioning performed better than clinical examination, which failed to detect expulsion after postpartum insertion in 75% of the cases (9 from 12 cases).

Urinary protein/creatinine ratio in hypertensive pregnant women

OBJECTIVES

To determine the correlation between the protein/creatinine ratio and 24-h proteinuria; to estimate the sensitivity and specificity of this ratio for the diagnosis of significant proteinuria; to establish its cutoff point with the best predictive value for the diagnosis of significant proteinuria in patients with systemic arterial hypertension.

STUDY DESIGN

A cross-sectional study of 47 hypertensive patients who had been pregnant for 20 weeks or more seen at the Maternity of the University Hospital of Porto Alegre. The studied factor was the protein/creatinine ratio measured in a single random urine sample and the outcome was protein determination in 24-h urine. The level of significance was set at 0.05.

RESULTS

The correlation coefficient between the protein/creatinine ratio and 24-h proteinuria was 0.94 when urine was properly collected. A receiver-operator characteristic curve was constructed to determine the sensitivity and specificity of the ratio for the diagnosis of significant proteinuria (> or = 300 mg in 24 h). Specificity and predictive positive value were 100% for a ratio > or = 0.8. The best values for sensitivity, specificity, positive predictive value, and negative predictive value in the diagnosis of proteinuria > or = 300 mg in 24 h were obtained when the protein/creatinine ratio was 0.5 (0.96, 0.96, 0.96, and 0.96, respectively).

CONCLUSION

The protein/creatinine ratio measured in a single urine sample taken at random from hypertensive pregnant women showed good sensitivity and specificity for the diagnosis of 24-h proteinuria > or = 300 mg and was strongly correlated with 24-h proteinuria. A ratio of 0.5 mg/mg is predictive of significant proteinuria and can be used for the diagnosis and follow-up of hypertensive pregnant women.

Calciuria and preeclampsia

Urinary calcium excretion has been reported to be diminished in preeclampsia. The objective of the present study was to determine urinary calcium excretion in pregnant patients with chronic arterial hypertension (CAH) and preeclampsia (PE), and in normotensive patients (N). Forty-four pregnant patients (gestational age, 20-42 weeks; 18 CAH, 17 PE, 9 N) were evaluated for calciuria, proteinuria, plasma uric acid and blood pressure. Patients with PE (82 +/- 15.1 mg/24 h) showed significantly lower calciuria (P < 0.05) than the group with CAH (147 +/- 24.9 mg/24 h) and the N group (317 +/- 86.0 mg/24 h) (P < 0.05, Student t-test). Plasma uric acid was significantly higher in the PE group (6.1 +/- 0.38 mg/dl) than the CAH group (5.0 +/- 0.33 mg/dl; P < 0.05), which also presented higher proteinuria levels, although the difference was not statistically significant. Diastolic and systolic blood pressure did not differ between the PE (164 +/- 105 mmHg) and CAH (164 +/- 107 mmHg) groups. Calciuria was significantly lower in the group with preeclampsia than in the group with chronic arterial hypertension. We conclude that calciuria can be a further factor for identifying preeclampsia.