Twenty-four hour blood pressure monitoring in early pregnancy: is it predictive of pregnancy-induced hypertension and preeclampsia?

OBJECTIVE: To investigate whether a chronobiological analysis applied to automated 24-hour blood pressure monitoring in early pregnancy provides objective parameters enabling detection of single patients at risk of pregnancy-induced hypertension or preeclampsia. METHODS: 24-hour automatic blood pressure monitoring was performed at 8-16 and 20-25 gestational weeks in 104 women at risk of pregnancy-induced hypertension or preeclampsia. The subjects were hospitalized to be synchronized to rest-activity and meal-timing schedules. All women were followed longitudinally until post-partum. Chronobiological analysis of blood pressure values was performed; sensitivity, specificity and predictive values of MESOR and hyperbaric index were also calculated. Incidence of pregnancy-induced hypertension or preeclampsia, gestational week at delivery and birthweight were recorded. RESULTS: Nine thousand nine hundred and eighty-four blood pressure measurements were analyzed. In patients who later developed overt hypertension, systolic and diastolic blood pressure MESOR, hyperbaric index and percent time elevation were already significantly higher in early pregnancy than in those who remained normotensive. The best sensitivity and specificity was obtained between 20-25 weeks of gestation with systolic single cosinor MESOR and Hyperbaric Index using as cut-off 103 mmHg (sensitivity: 88%; specificity: 75%) and 10 mmHg/24 hour (sensitivity: 70%; specificity: 92%), respectively. CONCLUSIONS: The chronobiological analysis applied to 24-hour blood pressure monitoring during pregnancy allows definition of objective cut-off values which can be particularly useful in the routine clinical practice when the risk of developing pregnancy-induced hypertension or preeclampsia must be calculated in the individual subject.

24-hour blood pressure monitoring to evaluate the effects of nifedipine in pre-eclampsia and in chronic hypertension in pregnancy.

OBJECTIVE: To investigate the effect of 7 to 14 days of therapy with nifedipine (sustained-release preparation) on the 24-hour blood pressure patterns of pregnant women with pre-eclampsia or chronic hypertension, and to test the utility of blood pressure monitoring in modulating the timing and dosage of the drug. DESIGN: 24-hour automatic blood pressure monitoring of pregnant women with pre-eclampsia or chronic hypertension before and after nifedipine treatment. SETTING: Centre for Prevention, Diagnosis and Treatment of Hypertension in Pregnancy, University of Turin, Italy. POPULATION: Sixteen pregnant women with pre-eclampsia and 17 with chronic hypertension. METHODS: 24-hour blood pressure monitoring was performed before the beginning of the therapy and after 7 to 14 days of treatment with sustained-release nifedipine. MAIN OUTCOME MEASURES: Chronobiological analysis of systolic and diastolic blood pressure values was performed; MESOR, amplitude, acrophase, hyperbaric index, percent time elevation and significance of rhythm were calculated before and after treatment. RESULTS: 6336 blood pressure measurements were analysed. Systolic and diastolic MESOR values were significantly decreased after nifedipine treatment both in pre-eclampsia and in chronic hypertension. However, the antihypertensive effect of nifedipine in pre-eclampsia was especially pronounced during evening and night, while in chronic hypertension it was more constant during the 24-hour period. 24-hour blood pressure monitoring allowed adjustment, when necessary, to the timing and dosage of nifedipine in accordance with the blood pressure patterns of each patient, using the hyperbaric index and percent time elevation as objective parameters for the evaluation of treatment efficacy. CONCLUSIONS: 24-hour blood pressure monitoring is a good method to optimise treatment, and confirms that nifedipine is useful for the control of maternal blood pressure in pregnancy.

Thyroid hormones in tissues from human embryos and fetuses.

This study was intended to quantify T3 and T4 in various human tissues at different stages of gestation as a contribute in the evaluation of the role of thyroid hormones in fetal development, particularly before the maturation of fetal thyroid function. Moreover, for a better comprehension of the influence of thyroid hormone status in tissues, the study was extended to adults. Embryonic specimens were obtained from voluntary abortions between 6 and 12 weeks of gestation, fetal and neonatal specimens from fetuses and neonates between 15 and 36 weeks of gestation after spontaneous abortion or stillbirth, and adult specimens from men (age range: 45-65 years) after death for cardiovascular diseases. Thyroid hormones were measured by the method of Gordon and coworkers. In embryos T3 and T4 were measured in limbs, carcasses, brain and liver: considering all values measured in the period 9-12 weeks, a mean concentration of 0.11 ng/g for T3 and 1.28 ng/g for T4 was obtained. In pooled limbs of 6-8 weeks T3 was barely measurable (0.01 ng/g). In the carcasses there was an increase in T3 and T4 concentrations of 40 and 20 times respectively from the 9th to the 12th week, when thyroid follicles organization takes place. In fetuses and adults T3 and T4 were measured in brain, heart, kidney, liver, lung, skeletal muscle and skin (mean concentrations: 0.86 ng/g for T3 and 7.44 ng/g for T4 in fetuses and neonates; 1.36 ng/g for T3 and 12.75 ng/g for T4 in adults). Hormones concentration increased with gestational age; the T3/T4 ratio increased until 22-24 weeks, when the prevalent increment in T4 occurs. T3 concentration up to 30 weeks was generally higher in tissues than in cord serum of the corresponding age. During the last month of gestation T3 increment was faster in serum. T4 level was always predominant in serum. In conclusion, T3 and T4 have been detected in the limbs of embryos before the onset of thyroid hormone secretion. Concentrations were 1/150 and 1/70, of the normal maternal blood values respectively. It is conceivable that these hormones are of maternal origin, and the question of whether such small quantities may play a role in fetal development is open.