Water Immersion and Changes in the Fetoplacental Circulation. A Case-Control Study With the Case as it's Own Control.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 25
- 试验地点
- 2
- 主要终点
- Changes in pulsatility index in umbilical and uterine arteries following immersion into water
研究概览
简要总结
Pregnant women with pre-eclampsia and growth restricted fetuses often have a reduced function of the placenta. This is accompanied by an increased perinatal mortality and morbidity.
By ultrasound it is possible to measure blood flow and vascular resistance in both the fetal umbilical cord and in the blood vessels supplying the uterus. A high resistance in these vessels occur before the child is severely affected.
By immersion in water extracellular fluid is redistributed back into the circulation, and central blood volume increases. Previous studies have shown that maternal minute-volume increases, while blood pressure drops slightly. Also an increased amniotic fluid has been recorded. This has been interpreted as an expression of increased renal blood flow. Immersion into water could increase blood flow in the vessels supplying the uterus and thus increase blood flow to the child.
The investigators aim to clarify this by examining blood flow and resistance in the blood vessel supplying the uterus and in the umbilical cord, while the participant is immersed into water. Initially, 25 healthy women with an uncomplicated singleton pregnancy recruited from the Department of Obstetrics and Gynaecology: Hvidovre University Hospital, Denmark, will be examined. The participant will act as its own control and measurements above water and immersed will be conducted at the same study session.
Ultimately the investigators seek to contribute to a non-invasive option for prolonging those pregnancies where the fetus and/or maternal condition requires delivery several weeks before term, and where immersion of the pregnant woman in the water a few hours one to several times daily, may prolong the pregnancy the required number of hours/days for antenatal steroid treatment to be sufficient.
There are no risks associated with the study and the project team considers it ethical to implement this. The study is not supported by pharmaceutical companies or other groups with economic interests. The project group itself has taken the initiative to study.
详细描述
Intrauterine growth retardation and preeclampsia are major causes of neonatal mortality, morbidity and later neurological sequelae. The conditions are associated with an increased resistance to blood flow in the placenta, that can be detected by an increase in pulsatility index (PI) in the umbilical artery (1).
When Doppler flow is assessed in the uterine arteries, increased resistance in the uteroplacental circuit is indicated both by an increase in PI and by a change in the flow velocity waveform, which can be seen as a "notch" in early diastole.
In the 2nd trimester, the invasion of trophoblasts and the remodeling of the uterine spiral arteries are complete. Persistence of a bilateral notch beyond the 24th week of gestation is associated with an increased risk of intrauterine growth retardation and preeclampsia. Even though the risk persists, the notch usually disappears later in pregnancy (2).
When the non-pregnant body is immersed in water, extracellular fluid is redistributed back into the circulation. Central blood volume, cardiac output, renal perfusion and urine output increase and the blood pressure falls (3-7).
The same changes occur in the pregnant women. However the increased diuresis is strongly correlated with the degree of the pregnancy edema, which decreases substantially (8), and the amount of amniotic fluid increases (9). The changes all occur within minutes (8), but are transient and return to conditions before immersion within 1-2 hours after the pregnant woman has come out of the water.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Singleton pregnant women
- •Normal weight fetuses
- •Normal first trimester combined screening
- •Normal second trimester ultrasound scan for fetal abnormalities
排除标准
- •Cardiovascular disease
- •Thyroid disease
- •Abuse of medication, alcohol- or drugs
- •Medical treatment of hypertension
- •Medical treatment of depression or any other psychiatric disorder
- •Ongoing infection
- •Placenta previa
- •Premature rupture of membranes
- •Body mass index above 35
结局指标
主要结局
Changes in pulsatility index in umbilical and uterine arteries following immersion into water
时间窗: After 5 and 25 minutes of immersion and after 15 and 30 past immersion
次要结局
- Changes in maternal mean arterial pressure and in amniotic fluid following immersion into water(After 5 and 25 minutes of immersion and after 15 and 30 minutes past immersion)
研究者
Dorthe Thisted
Specialist trainee
Hvidovre University Hospital