The Role of Fetal Ductus Arteriosus in Predicting Spontaneous Preterm Birth

Study Overview
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Brief Summary
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Preterm birth still remains a major cause of perinatal morbidity and mortality worldwide. The exact mechanism stimulating term and preterm births in humans is still unknown. Prostaglandins, by mediating cervical ripening and early stimulation of myometrial contractions, are likely to play a major role in the parturition process. Much of the unique fetal circulation is facilitated by the ductus arteriosus. Patency of the ductus arteriosus in utero is primarily maintained via prostaglandins which are highly expressed by smooth muscle cells located in the media of the ductus arteriosus. The primary objective of this study is to prospectively assess whether any changes in the fetal ductus arteriosus parameters exist at 32 weeks' gestation. The secondary objective is to investigate whether there is an association between the ductus arteriosus parameters and the time to delivery interval at 32 weeks' gestation.

Detailed Description
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The rationale is to assess whether physiological responses that occur around the time of delivery, in both the mother and the fetus (elevated prostaglandins level), can be quantified using ultrasound of the fetal ductus arteriosus. Whether or not the ductus arteriosus plays an active physiological role in the initiation of parturition is unknown. Since prostaglandins are physiologically highly expressed within the fetal ductus arteriosus and also linked to some critical steps throughout parturition, it is hypothesized that structural and doppler flow pattern variations of the ductus arteriosus exist in the period surrounding the birth. These changes might occur before or after the intrinsic rise of prostaglandins and could be quantified using prenatal ultrasound of the fetal ductus arteriosus. Identifying new physiological based variables that can assist in predicting the onset of labour, especially surrounding preterm birth, as the one suggested in the current study, is thus of great importance and may provide invaluable information into the overall future care and decision making during pregnancy, especially around the time of delivery. It may assist in creating future recommendations for pregnant women and improved healthcare standards during the delivery process.

Official Title
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The Role of Fetal Ductus Arteriosus in Predicting Spontaneous Preterm Birth

Conditions
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Ductus Arteriosus

Intervention / Treatment
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* Other: Ultrasound examination


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Low risk singleton pregnancy at 32 weeks gestation. Exclusion criteria: Smoking Underlying cardiac or respiratory illness Fetal growth restriction Medicated gestational hypertension or evolving preeclampsia Gestational diabetes controlled with insulin or oral medications Use of steroids for lung maturation in the current pregnancy Known major congenital anomalies.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Ultrasound examination<br>Participants will undergo an ultrasound examination at 32 weeks gestation. | Other: Ultrasound examination<br>* Participants will undergo ultrasound examination at 32 weeks gestation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fetal ductus arteriosus changes | To prospectively assess any changes in blood flow in the fetal ductus arteriosus at 32 weeks' gestation. | 32 weeks gestation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to delivery | To investigate whether there is an association between the ductus arteriosus parameters and the time to delivery interval at 32 weeks' gestation. | 32 weeks gestation to delivery |