Effect of esophageal ligation on amniotic fluid volume and urinary flow rate in fetal sheep

Larry C. Matsumoto, Cecilia Cheung, Robert A. Brace

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

OBJECTIVE: Although the fetus normally swallows large volumes of amniotic fluid each day, it is unclear whether amniotic fluid volume increases after fetal esophageal obstruction or whether fetal urine production changes. Our objective was to determine the effects of fetal esophageal ligation on amniotic fluid volume and urinary flow rate over time. STUDY DESIGN: Seven late-gestation fetal sheep underwent esophageal ligation, and 7 served as time control animals. The urachus was ligated to eliminate urine flow to the allantoic cavity. On days 1,3, 5, 7, and 9 after surgery, we measured the composition of amniotic fluid, fetal urine, and fetal and maternal blood, as well as amniotic fluid volume and fetal urinary flow rate. A 3-factor analysis of variance was used for statistical analysis. RESULTS: Amniotic fluid volume did not change with time in the control group, averaging 876 ± 142 mL (mean ± SEM), and it decreased in the esophageal ligation group (P = .020), averaging 309 ± 75 mL on day 9. Fetal urinary flow rate was lower (P = .0063) in the esophageal ligation group (431 ± 27 mL/d) than in the control group (631 ± 54 mL/d). There were no differences in fetal or maternal blood compositions between the two groups. Amniotic fluid sodium and chloride increased in the ligated animals. CONCLUSION: Polyhydramnios did not occur after esophageal ligation, even though the fetuses excreted approximately 4000 mL of urine over the 9-day study period. This suggests that intramembranous absorption is substantially increased. With only small changes in amniotic solute concentrations, intramembranous solute absorption must occur simultaneously with water, suggesting a near- zero reflection coefficient for solutes. We speculate that fetal urine, lung secretions, or both contain a factor that increases intramembranous permeability.

Original languageEnglish (US)
Pages (from-to)699-705
Number of pages7
JournalAmerican Journal of Obstetrics and Gynecology
Volume182
Issue number3
StatePublished - 2000
Externally publishedYes

Fingerprint

Amniotic Fluid
Ligation
Sheep
Urine
Fetus
Urachus
Mothers
Polyhydramnios
Control Groups
Deglutition
Fetal Blood
Sodium Chloride
Statistical Factor Analysis
Permeability
Analysis of Variance
Pregnancy
Lung
Water

Keywords

  • Amniotic fluid
  • Esophageal ligation
  • Renal function
  • Urinary flow

ASJC Scopus subject areas

  • Medicine(all)
  • Obstetrics and Gynecology

Cite this

Effect of esophageal ligation on amniotic fluid volume and urinary flow rate in fetal sheep. / Matsumoto, Larry C.; Cheung, Cecilia; Brace, Robert A.

In: American Journal of Obstetrics and Gynecology, Vol. 182, No. 3, 2000, p. 699-705.

Research output: Contribution to journalArticle

Matsumoto, Larry C. ; Cheung, Cecilia ; Brace, Robert A. / Effect of esophageal ligation on amniotic fluid volume and urinary flow rate in fetal sheep. In: American Journal of Obstetrics and Gynecology. 2000 ; Vol. 182, No. 3. pp. 699-705.
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