Changes in maternal nutrition during pregnancy can result in profound effects on placental function and fetal development. Although the preconceptional period holds the potential to reprogram embryonic and placental development, little is known regarding the effects of premating nutritional manipulation on placental function and fetal and postnatal offspring growth. To test this, Polypay-Dorset sheep (n = 99) were assigned to 1 of 3 nutritional treatments (n = 33/treatment) receiving 50% (UN: undernutrition), 100% (C: control), or 200% (ON: overnutrition) of maintenance energy requirements for 21 d before mating during April–May (increasing photoperiod). Thereafter, diets were the same across groups. We evaluated maternal reproductive variables and maternal and offspring weight and body mass index through weaning. Maternal plasma was collected through pregnancy until postnatal day 1 to assay pregnancy-associated glycoproteins (PAGs) and progesterone. Fertility rate was similar among treatments, but ON females had a higher reproductive rate (UN: 82%; C: 100%, ON: 145%). When correcting by total birth weight, twin pregnancies had lower PAGs and progesterone versus singleton pregnancies (P < 0.001). At birth, UN lambs were heavier than C lambs regardless of birth type (P < 0.01). Growth velocity, daily gain, and weaning weight were similar, but UN and ON females grew faster and were heavier at weaning versus C females. We demonstrated that a 3-wk preconceptional maternal undernutrition or overnutrition, when correcting by total birth weight, results in lower endocrine capacity in twin pregnancies. Preconceptional maternal undernutrition and overnutrition increased postnatal female lamb growth, suggestive of reprogramming of pathways regulating growth before conception. This highlights how preconceptional nutrition can result in marked sex-specific differences.

怀孕期间母体营养的变化会对胎盘功能和胎儿发育产生深远的影响。尽管孕前期具有重新编程胚胎和胎盘发育的潜力，但关于孕前营养操作对胎盘功能以及胎儿和产后后代生长的影响知之甚少。为了测试这一点，Polypay-Dorset 绵羊（n = 99）被分配到 3 种营养治疗中的一种（n = 33/治疗），接受 50%（UN：营养不足）、100%（C：对照）或 200%（ON ：4 月至 5 月交配前 21 天维持能量需求的营养过剩（增加光周期）。此后，各组的饮食相同。我们通过断奶评估了母亲的生殖变量以及母亲和后代的体重和体重指数。在怀孕期间收集母体血浆直至产后第 1 天，以测定妊娠相关糖蛋白 (PAG) 和孕酮。处理之间的生育率相似，但 ON 女性的繁殖率更高（UN：82%；C：100%，ON：145%）。当按出生总重进行校正时，双胎妊娠的 PAG 和孕酮低于单胎妊娠。P < 0.001)。出生时，无论出生类型如何，UN 羔羊都比 C 羔羊重（P < 0.01）。生长速度、日增重和断奶体重相似，但 UN 和 ON 雌性与 C 雌性相比，生长速度更快，断奶时更重。我们证明了 3 周孕前孕产妇营养不良或营养过剩，当通过总出生体重进行纠正时，会导致双胎妊娠的内分泌能力降低。孕前母体营养不良和营养过剩会增加产后雌性羔羊的生长，这表明在受孕前调节生长的途径重新编程。这凸显了孕前营养如何导致显着的性别差异。