Uterine, Fetal Cerebral Doppler and Oligohydramnios to Predict Abnormal Heart Rate Tracings in Postterm Pregnancies

Hospital Universitario Dr. Jose E. Gonzalez

Status: Completed

Conditions: Late Pregnancy; Abnormality in Fetal Heart Rate or Rhythm; Ultrasound

Treatments: Diagnostic Test: Ultrasound and Doppler ultrasound

Study type: Observational

Funder types: Other

Identifiers

NCT03703037

GI17-00009

Details and patient eligibility

About

Objective: To estimate the value of uterine, fetal cerebral Doppler and oligohydramnios to predict abnormal fetal heart rate tracings in pregnancies at or beyond 41 weeks

Full description

This will be a nested case-control study that was conducted at University Hospital Dr. Jose E. Gonzalez after the approval of Institutional ethical committee. Women with low risk late term or postterm pregnancy (at least 41 weeks) with confirm gestational age who will be referred to our Maternal-fetal unit and admitted 1 to 2 days prior to induction of labour according institutional protocol will be recruited and constitute the cohort.

Cases will be patients with abnormal intrapartum cardiotocogram (category III fetal heart rate tracing). For each case, four controls will be matched. The primary outcome will be to obtain odds ratios for the Doppler parameters (middle cerebral artery pulsatility index, mean uterine artery pulsatility index and Middle cerebral artery pulsatility index to mean uterine artery pulsatility index ratio) and amniotic fluid index that would be associated with intrapartum category III fetal heart rate tracing.

Enrollment: 227 patients

Sex: Female

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Singleton pregnancy
• Gestational age of at least 287 days (41 weeks)
• Low risk pregnancy (defined as the absence of maternal or fetal complications other than postterm pregnancy)

Exclusion criteria

• Twin or multiple gestation
• Uncertain gestational age
• Non vertex presentation
• Estimated fetal weight below the 10th percentile for gestational age (Hadlock´s formula)
• Fetal macrosomia (estimated fetal weight ≥ 4 Kilos) diagnosed by clinical measurement (Johnson´s technique) or ultrasound measurement (Hadlock´s formula).
• Fetal abnormalities found on routine anomaly scan.
• Maternal medical disorder (preeclampsia, chronic hypertension, diabetes, lupus, hyperthyroidism)
• Prelabour rupture of membranes
• Antepartum hemorrhage
• Any fetopelvic disproportion that could create dystocia during labor.

Trial design

227 participants in 3 patient groups

Cohort

Description:

This will be a nested case-control study. Women with low risk pregnancies at or beyond 41 weeks, who will be referred to our Maternal-fetal unit and admitted 1 to 2 days prior to induction of labour according institutional protocol will constitute the cohort. Then women with intrapartum abnormal fetal heart rate tracings (cases) will be identified and match with controls. The primary outcome will be to obtain odds ratios for the Doppler ultrasound parameters (middle cerebral artery pulsatility index, mean uterine artery pulsatility index and Middle cerebral artery pulsatility index to mean uterine artery pulsatility index ratio) and Ultrasound assessment of amniotic fluid index that would be associated with intrapartum category III fetal heart rate tracing.

Treatment:

Diagnostic Test: Ultrasound and Doppler ultrasound

Cases

Description:

Cases will be patients with abnormal intrapartum cardiotocogram (category III fetal heart rate tracing). Intervention: Ultrasound and Doppler ultrasound

Treatment:

Diagnostic Test: Ultrasound and Doppler ultrasound

Controls

Description:

Those will be patients with normal intrapartum cardiotocogram (category I fetal heart rate tracing) or category II that converted into category I after intrauterine resuscitation methods. Intervention: Ultrasound and Doppler ultrasound

Treatment:

Diagnostic Test: Ultrasound and Doppler ultrasound