Abstract
We quantified the respiratory activity of 9 fetal lambs using computer-analysis of the diaphragmatic electromyogram (EMG) obtained during 2 h recording sessions interspersed over the last 13 days of gestation. The fetuses delivered unassisted at an average gestational age of 145 days (term = 147 days). During the last 2 h of labour the number of phasic EMG bursts (breaths) averaged 3% of the peak recorded earlier in the study. This decline in breathing began at least 2 days before labour and resulted predominantly from the fetus spending an increasing proportion of time in apnoea. Respiratory rate within epochs of breathing also fell significantly 1 day before labour, and the proportion of time spent in the low voltage electrocortical state declined once labour commenced. No significant change occurred in arterial PO2, PCO2 or pH over the study period. We conclude that fetal respiratory activity falls well before the onset of labour, largely as a result of increased apnoea, and that the decline does not result from the development of a progressive hypoxaemia associated with labour.
| Original language | English |
|---|---|
| Pages (from-to) | 55-68 |
| Number of pages | 14 |
| Journal | Respiration Physiology |
| Volume | 65 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Jan 1986 |
Keywords
- Arterial blood
- Breathing pattern
- Diaphragm
- Fetus
- Gestation
- Labour
- Lamb
- Newborn mammal
Cite this
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Phasic respiratory activity in the fetal lamb during late gestation and labour. / Berger, P. J.; Walker, A. M.; Horne, R.; Brodecky, V.; Wilkinson, M. H.; Wilson, F.; Maloney, J. E.
In: Respiration Physiology, Vol. 65, No. 1, 01.01.1986, p. 55-68.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Phasic respiratory activity in the fetal lamb during late gestation and labour
AU - Berger, P. J.
AU - Walker, A. M.
AU - Horne, R.
AU - Brodecky, V.
AU - Wilkinson, M. H.
AU - Wilson, F.
AU - Maloney, J. E.
PY - 1986/1/1
Y1 - 1986/1/1
N2 - We quantified the respiratory activity of 9 fetal lambs using computer-analysis of the diaphragmatic electromyogram (EMG) obtained during 2 h recording sessions interspersed over the last 13 days of gestation. The fetuses delivered unassisted at an average gestational age of 145 days (term = 147 days). During the last 2 h of labour the number of phasic EMG bursts (breaths) averaged 3% of the peak recorded earlier in the study. This decline in breathing began at least 2 days before labour and resulted predominantly from the fetus spending an increasing proportion of time in apnoea. Respiratory rate within epochs of breathing also fell significantly 1 day before labour, and the proportion of time spent in the low voltage electrocortical state declined once labour commenced. No significant change occurred in arterial PO2, PCO2 or pH over the study period. We conclude that fetal respiratory activity falls well before the onset of labour, largely as a result of increased apnoea, and that the decline does not result from the development of a progressive hypoxaemia associated with labour.
AB - We quantified the respiratory activity of 9 fetal lambs using computer-analysis of the diaphragmatic electromyogram (EMG) obtained during 2 h recording sessions interspersed over the last 13 days of gestation. The fetuses delivered unassisted at an average gestational age of 145 days (term = 147 days). During the last 2 h of labour the number of phasic EMG bursts (breaths) averaged 3% of the peak recorded earlier in the study. This decline in breathing began at least 2 days before labour and resulted predominantly from the fetus spending an increasing proportion of time in apnoea. Respiratory rate within epochs of breathing also fell significantly 1 day before labour, and the proportion of time spent in the low voltage electrocortical state declined once labour commenced. No significant change occurred in arterial PO2, PCO2 or pH over the study period. We conclude that fetal respiratory activity falls well before the onset of labour, largely as a result of increased apnoea, and that the decline does not result from the development of a progressive hypoxaemia associated with labour.
KW - Arterial blood
KW - Breathing pattern
KW - Diaphragm
KW - Fetus
KW - Gestation
KW - Labour
KW - Lamb
KW - Newborn mammal
UR - http://www.scopus.com/inward/record.url?scp=0022544159&partnerID=8YFLogxK
U2 - 10.1016/0034-5687(86)90006-X
DO - 10.1016/0034-5687(86)90006-X
M3 - Article
VL - 65
SP - 55
EP - 68
JO - Respiration Physiology
JF - Respiration Physiology
SN - 0034-5687
IS - 1
ER -