Goat Fetuses Disconnected from the Placenta, but Reconnected to an Artificial Placenta, Display Intermittent Breathing Movements

Abstract

To investigate whether placental factors are involved in the intermittent breathing movements in goat fetuses, we assessed electrocortical activity (ECoA) and tracheal pressure in 5 fetuses (124–135 days) separated from the placenta and connected for 48 h to an extrauterine fetal incubation system that provided umbilical arteriovenous extracorporeal membrane oxygenation. The fetal physiological condition on this system was almost the same as that in utero for at least 48 h after the preparation. All fetuses showed intermittent low-voltage ECoA and breathing movements. The breathing movements occurred almost exclusively during periods of low- voltage ECoA. The proportions of time spent in low-voltage ECoA and breathing movements were 48–57% and 46–56%, respectively. In conclusion, breathing movements of fetuses on the extrauterine incubation system were episodic, suggesting that intermittent breathing movements are intrinsic to fetuses, independent of placenta-derived factors.

Effect of Low Dose of hCG on Induction of Fertile Estrus in Shiba Goats Pretreated Intravaginally with Progesterone during the Early Postpartum Nursing Period.

“…48: [497][498][499][500][501][502][503][504] 2002) hiba goats originated from a Japanese native dwarf breed and are known to be continuous breeders [1]. The Shiba and other dwarf goats have b een u s ed fo r va ri o us r es ear c h es , s u ch as r epr od uct ive phys io logy and pat ho log y of ruminant [2,3], physiology of fetus [4], cloning of animals [5], and thus recent demand for the goat has been expanding. In order to improve the reproductive efficiency of the Shiba goat, the interval from parturition to conception needs to be shortened.…”

The artificial womb

“…These new methods dramatically improved the prognosis of markedly premature newborns. More recently, a new system called extrauterine fetal incubation (EUFI), which used cannulation of the umbilical vein and artery that were connected to the circuit, was tested on a baby goat that was ultimately extracted by cesarean section at 148 days of pregnancy 40–44 …”

Power Spectral Analysis of the Heart Rate Variability of Goat Fetuses During Extrauterine Incubation

“…An episode of FBM was defined as negative fluctuations between −2 and −5 mm Hg in tracheal pressure lasting for 60 s (6). That of no‐FBM was defined as an absence of negative fluctuations in tracheal pressure lasting for 60 s or longer (6). ECoA was classified into two epochs (high‐ and low‐voltage ECoA) by visual inspection.…”