NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Hypergravity Effects on Rodent Pregnancy and ParturitionNo mammal has yet undergone birth, or parturition, in the microgravity of space. Previous studies (Ronco & Alberts, 2000) have shown that mid-pregnant rat dams exposed to spaceflight (0-g) and landed 48-72 hrs before term successfully delivered robust, healthy offspring Microgravity-exposed dams exhibited twice the expected numbers of labor contractions whereas length of pregnancy, duration of labor, fetal wastage, number of neonates born and litter gender ratios were identical to controls. In the present study, we report the results of rodent pregnancy and parturition at the opposite end of the gravity spectrum, in hypergravity. Dams exposed to either: 1.0-g, 1.5-g, 1.75-g or 2.0-g from Gestational day (G) 11 and throughout the births of their litters had comparable pregnancy and labor durations, fetal wastage, numbers of neonates born and litter Tender ratios. During parturition, hypergravity-exposed dams exhibited significantly fewer labor contractions as compared to 1.0-g controls. Dams that underwent birth in hypergravity had significantly fewer offspring surviving the immediate postpartum period (P1: 1.0-g, 11.92 +/- 2.84; 1.5-g, 10.88 +/- 2.17; 1.75-g, 9.22 +/-1.99; 2.0-g, 8.83 +/- 3.31). Within 24 hrs postpartum, neonatal survival was further diminished in hypergravity [P2: 100% (1.0-g); 96% (1.5-g); 96% (1.75-g); 73% (2.0-g)] and continued to decline (P10: 100%(1.0-g.); 90%(1.5-g); 87%(1.75-g), 40%(2.0-g)]. Neonatal losses stabilized by P5 for the 1.5-g andl.75-g conditions but continued until P9 for the 2.0-g condition. Together, these findings show that postnatal, but not prenatal, survival is compromised following birth in hypergravity, Maternal and neonatal factors that contribute to peri-parturitional vulnerability to altered gravity environments will be discussed.
Document ID
20030001110
Acquisition Source
Ames Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Ronca, A. E.
(NASA Ames Research Center Moffett Field, CA United States)
Baer, L. A.
(Lockheed Martin Corp. Moffett Field, CA United States)
Mills, N. A.
(California Univ. Davis, CA United States)
Wade, C. E.
(NASA Ames Research Center Moffett Field, CA United States)
Dalton, Bonnie
Date Acquired
August 21, 2013
Publication Date
January 1, 2002
Subject Category
Life Sciences (General)
Funding Number(s)
PROJECT: RTOP 121-10-30
PROJECT: RTOP 121-10-50
PROJECT: RTOP 121-40-10
CONTRACT_GRANT: NIMH-MH46485
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available