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Regulation of Placental Vascular Reactivity in Pregnancy-induced Hypertension

Completed
Conditions
Heart Diseases
Hypertension
Pregnancy Toxemias
Cardiovascular Diseases
Registration Number
NCT00005208
Lead Sponsor
National Heart, Lung, and Blood Institute (NHLBI)
Brief Summary

To elucidate the role of an imbalance in vasodilator prostacyclin (PGI2) and vasoconstrictor thromboxane (TxA2) in pregnancy-induced hypertension

Detailed Description

BACKGROUND:

Pregnancy-induced hypertension (PIH) is associated with increased fetal and neonatal morbidity and mortality possibly resulting from hypoxia in utero. The primary pathology of PIH involves a reduction in uteroplacental blood flow but modern imaging techniques have now shown that increased impedance of the fetal-placental circulation and hence reduced blood flow can also be found in PIH. This may represent a direct effect of hypoxia or be a fetal adaptation to increase placental oxygen extraction to relieve hypoxia. The fetal-placental circulation is regulated by humoral agents and vascular pressure. An imbalance of vasodilator prostacyclin (PGI2) and vasoconstrictor thromboxane (TxA2) production is reported to underlie the vasoconstriction seen in PIH.

The study resulted from the 1986 release of a Request for Applications for Research on Hypertension in Pregnancy by the National Heart, Lung, and Blood Institute and the National Institute of Child Health and Human Development.

DESIGN NARRATIVE:

The fetal-placental circulations of perfused human placental cotyledons from normotensive and pregnancy-induced hypertensive pregnancies were used to determine if an imbalance in PGI2/TxA2 production existed and its relationship to the responses of the fetal-placental circulation to vasoconstriction. Studies were also conducted on the effects of hypocalcemia and hypomagnesemia, hypoxia, and drugs.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
Not specified
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Secondary Outcome Measures
NameTimeMethod
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