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Amniotic fluid composition and fetal and placental growth rates in genetically hypertensive and normotensive rats

Version 2 2024-06-13, 09:10
Version 1 2015-08-14, 12:11
journal contribution
posted on 2024-06-13, 09:10 authored by E Erkadius, TO Morgan, R Di Nicolantonio
Reduced birth weight has been observed in offspring of the spontaneously hypertensive rat (SHR) and in human hypertension. To determine which uterine factors might contribute to this fetal underdevelopment, fetal and placental growth rates and the volume and composition of amniotic fluid were measured in SHR and normotensive control Wistar Kyoto (WKY) rats during the final trimester of intra-uterine development. SHR and WKY fetuses were collected on Days 15-22 of pregnancy, and fetal and placental weight and amniotic fluid volume were recorded. The sodium and potassium concentrations of amniotic fluid were also measured. Placental weight was significantly lower in SHR than in WKY between Days 15 and 20 of gestation, but significantly higher on Days 21 and 22. Fetal weight was significantly lower in SHR between Days 17 and 22. These differences were reduced or abolished when fetal and placental weights were corrected for differences in maternal weight between strains. Amniotic fluid volume was significantly lower in SHR between Days 15 and 18, but significantly higher at Days 20, 21 and 22. Amniotic fluid sodium concentration was relatively constant over the period of observation and not different between strains. SHR amniotic fluid potassium concentration was significantly lower than that of WKY near term. Thus, the altered fetal and placental weight of SHR may be due to the overall reduced growth rate of this strain. However, the rate of fluid and electrolyte resorption close to term is markedly different between strains. The mechanism for this altered fluid and electrolyte handling by the SHR feto-placental unit remains to be determined.

History

Journal

Reproduction, fertility and development

Volume

7

Pagination

1563-1567

Location

Clayton, Vic.

ISSN

1031-3613

eISSN

1448-5990

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1995, CSIRO

Issue

6

Publisher

CSIRO