TY - JOUR
T1 - Postnatal outcomes in term and preterm lambs following fetal growth restriction
AU - Cock, M. L.
AU - Camm, Ej
AU - Louey, S.
AU - Joyce, Bj
AU - Harding, R.
N1 - Funding Information:
Liliana Borcea's work was partially supported by NSF Grant No. DMS1510429. Support from the Simons Foundation, Simons Fellowship Grant No. 339153, is also gratefully acknowledged.
PY - 2001
Y1 - 2001
N2 - 1. Epidemiological evidence indicates that low birthweight increases the risk of a number of adult-onset diseases. It is now apparent that many babies with a low birthweight may have been subjected to a combination of reduced growth rates in utero as well as preterm birth. However, the long-term effects of preterm birth following intra-uterine growth restriction (IUGR) are unknown. Thus, our objectives were: (i) to identify prenatal factors associated with preterm birth in IUGR fetuses; and (ii) to characterize postnatal effects of preterm birth following IUGR. 2. We studied pregnant sheep and their offspring, in which fetal growth was restricted by umbilico-placental embolization during late gestation. Some of these animals were born at term (146 ± 1 days) and some were born prematurely (139 ± 1 days). In both groups, we have conducted longitudinal studies of postnatal respiratory function, cardiovascular function and learning ability up to 6-8 weeks of age. 3. Before birth, IUGR fetuses born prematurely (P-IUGR) were more hypoxaemic and acidaemic and had higher haemoglobin concentrations than both control fetuses and IUGR fetuses born at term (T-IUGR). In P-IUGR fetuses, plasma cortisol concentrations increased earlier than in the two other groups. The P-IUGR lambs had lower birthweights than T-IUGR lambs and both groups of IUGR lambs remained lighter than controls for 8 weeks. 4. After birth, P-IUGR lambs were hypoxaemic compared with T-IUGR and control lambs. Pulmonary diffusing capacity (adjusted for lung volume) was significantly lower in both groups of IUGR lambs than in controls, with P-IUGR lambs having lower values than T-IUGR lambs. Lung compliance (adjusted for lung volume), was not different between P-IUGR and control lambs, but values were higher in T-IUGR lambs than in control and P-IUGR lambs. Chest wall compliance (adjusted for lung volume) was higher in both groups of IUGR lambs than in controls. 5. During the 8 week postnatal study period, both groups of UGR lambs had lower mean arterial pressures than control lambs; this relative hypotension was greatest in P-IUGR lambs. 6. In tests of learning ability, P-IUGR lambs took longer to complete a simple maze task at all ages and, in the second postnatal week, made a greater number of errors compared with controls. In an obstacle course, P-IUGR lambs recorded longer trial durations; they also made more errors than control lambs. 7. We conclude that preterm birth in the presence of late-gestational placental insufficiency and IUGR can result in specific effects on respiratory and cardiovascular development after birth, in addition to the effects of IUGR alone.
AB - 1. Epidemiological evidence indicates that low birthweight increases the risk of a number of adult-onset diseases. It is now apparent that many babies with a low birthweight may have been subjected to a combination of reduced growth rates in utero as well as preterm birth. However, the long-term effects of preterm birth following intra-uterine growth restriction (IUGR) are unknown. Thus, our objectives were: (i) to identify prenatal factors associated with preterm birth in IUGR fetuses; and (ii) to characterize postnatal effects of preterm birth following IUGR. 2. We studied pregnant sheep and their offspring, in which fetal growth was restricted by umbilico-placental embolization during late gestation. Some of these animals were born at term (146 ± 1 days) and some were born prematurely (139 ± 1 days). In both groups, we have conducted longitudinal studies of postnatal respiratory function, cardiovascular function and learning ability up to 6-8 weeks of age. 3. Before birth, IUGR fetuses born prematurely (P-IUGR) were more hypoxaemic and acidaemic and had higher haemoglobin concentrations than both control fetuses and IUGR fetuses born at term (T-IUGR). In P-IUGR fetuses, plasma cortisol concentrations increased earlier than in the two other groups. The P-IUGR lambs had lower birthweights than T-IUGR lambs and both groups of IUGR lambs remained lighter than controls for 8 weeks. 4. After birth, P-IUGR lambs were hypoxaemic compared with T-IUGR and control lambs. Pulmonary diffusing capacity (adjusted for lung volume) was significantly lower in both groups of IUGR lambs than in controls, with P-IUGR lambs having lower values than T-IUGR lambs. Lung compliance (adjusted for lung volume), was not different between P-IUGR and control lambs, but values were higher in T-IUGR lambs than in control and P-IUGR lambs. Chest wall compliance (adjusted for lung volume) was higher in both groups of IUGR lambs than in controls. 5. During the 8 week postnatal study period, both groups of UGR lambs had lower mean arterial pressures than control lambs; this relative hypotension was greatest in P-IUGR lambs. 6. In tests of learning ability, P-IUGR lambs took longer to complete a simple maze task at all ages and, in the second postnatal week, made a greater number of errors compared with controls. In an obstacle course, P-IUGR lambs recorded longer trial durations; they also made more errors than control lambs. 7. We conclude that preterm birth in the presence of late-gestational placental insufficiency and IUGR can result in specific effects on respiratory and cardiovascular development after birth, in addition to the effects of IUGR alone.
KW - Fetal
KW - Intra-uterine growth restriction
KW - Postnatal outcomes
KW - Preterm birth
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U2 - 10.1046/j.1440-1681.2001.03552.x
DO - 10.1046/j.1440-1681.2001.03552.x
M3 - Article
C2 - 11703400
AN - SCOPUS:0035165815
SN - 0305-1870
VL - 28
SP - 931
EP - 937
JO - Clinical and Experimental Pharmacology and Physiology
JF - Clinical and Experimental Pharmacology and Physiology
IS - 11
ER -