In recent decades, there has been a growing interest in the impact of insults during pregnancy on postnatal health and disease. It is known that changes in placental development can impact fetal growth and subsequent susceptibility to adult onset diseases; however, a method to collect sufficient placental tissues for both histological and gene expression analyses during gestation without compromising the pregnancy has not been described. The ewe is an established biomedical model for the study of fetal development. Due to its cotyledonary placental type, the sheep has potential for surgical removal of materno-fetal exchange tissues, i.e., placentomes. A novel surgical procedure was developed in well-fed control ewes to excise a single placentome at mid-gestation. A follow-up study was performed in a cohort of nutrient-restricted ewes to investigate rapid placental changes in response to undernutrition. The surgery averaged 19 min, and there were no viability differences between control and sham ewes. Nutrient restricted fetuses were smaller than controls (4.7 ± 0.1 kg vs. 5.6 ± 0.2 kg; P < 0.05), with greater dam weight loss (− 32.4 ± 1.3 kg vs. 14.2 ± 2.2 kg; P < 0.01), and smaller placentomes at necropsy (5.7 ± 0.3 g vs. 7.2 ± 0.9 g; P < 0.05). Weight of sampled placentomes and placentome numbers did not differ. With this technique, gestational studies in the sheep model will provide insight into the onset and complexity of changes in gene expression in placentomes resulting from undernutrition (as described in our study), overnutrition, alcohol or substance abuse, and environmental or disease factors of relevance and concern regarding the reproductive health and developmental origins of health and disease in humans and in animals.

中文翻译：

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开发一种在妊娠期从怀孕母羊身上取出胎盘的外科手术。

近几十年来，人们越来越关注怀孕期间的侮辱对产后健康和疾病的影响。众所周知，胎盘发育的变化会影响胎儿的生长和随后对成人发病的易感性；然而，尚未描述在妊娠期间收集足够的胎盘组织用于组织学和基因表达分析而不影响妊娠的方法。母羊是研究胎儿发育的既定生物医学模型。由于其子叶胎盘类型，羊具有手术切除母胎交换组织即胎盘的潜力。在喂养良好的对照母羊中开发了一种新的外科手术，以在妊娠中期切除单个胎盘。在一组营养受限的母羊中进行了一项后续研究，以调查对营养不良的反应胎盘的快速变化。手术平均 19 分钟，对照组和假母羊之间没有生存能力差异。营养受限的胎儿比对照组小（4.7 ± 0.1 kg vs. 5.6 ± 0.2 kg；P < 0.05），母畜体重减轻更大（- 32.4 ± 1.3 kg vs. 14.2 ± 2.2 kg；P < 0.01），胎盘更小尸检时（5.7 ± 0.3 g vs. 7.2 ± 0.9 g；P < 0.05）。取样胎盘的重量和胎盘数量没有差异。使用这种技术，绵羊模型的妊娠研究将深入了解由于营养不足（如我们的研究中所述）、营养过剩、酒精或药物滥用导致的胎盘基因表达变化的发生和复杂性，