母児相関の乳汁分泌と産褥期における母体プロラクチン分泌動態に及ぼす影響  [in Japanese] Effects of Mother-infant Interaction on MatemalMilk Secretion and Dynamics of Matemal Serum Prolactin Levels in Puerperium  [in Japanese]

母児相関の乳汁分泌に及ぼす影響を検討するために,昭和57年1月より2年間に当科にて正常経膣分娩となった母児共に異常のない183例を対象として,乳汁分泌量の経日的変化,母児同室制の乳汁分泌に及ぼす影響,産褥期における母体血中プロラクチンの動態を検討し以下の成績を得た.1)初産例と経産例では乳汁分泌量の経口的変化に有意の差は認められなかった.2)産褥1ヵ月間乳汁分泌量が十分で母乳のみで哺育出来た例では,産褥2日目に108.9±72.3ml(M±S.D.)の乳汁分泌がみられ,混合栄養例では27.3±36.5mlと有意に低下しており,この差は産褥6日目まで持続した(p<0.005).また産褥6日目までの総乳汁分泌量にも有意の差が認められた(母乳例:1636.7±591.9ml,混合例:778.2±580.6ml,p<0.005).3)母児同室例では異室例に比較して乳汁分泌量は有意に多く(産褥3日目で同室例:270.3±108.Oml,異室例:146.0±60.6ml,p<0.005),また同室例ではその後の母乳のみによる哺育例が有意に多かった(X^2=7.244,p<0.01).4)母体血中プロラクチン値は分娩24時間後に母乳例:336.7±171.3ng/ml,混合例:163.0±56.Ong/mlと母乳例で有意に高値を示した.5)児の啼泣により母体血中プロラクチン値は前値の平均を100%として,115.2±12.4%と上昇し,直接哺乳時(117.0±13.5%),搾乳時(117.3±12.6%)と同等の増加率を示した.6)産褥3〜5日目より母体血中プロラクチンのcircadian rhythmは回復し夜間に高値を示した(昼間:342.4±106.2ng/ml,夜間:562.3±173.4ng/ml,p<0.005).以上のことから,母児同室制は乳汁分泌を促進することが明らかとなり,乳汁分泌機構に関わる母児相関の意義が明確となった.またその背景には,母体血中プロラクチン分泌が深く関与していることが示唆された.

Effects of maternal-infant interaction on maternal milk secretion and the dynamics of maternal serum prolactin levels in puerperium were examined in 183 normally delivered mothers without any complications. No significant change was observed in the amount of maternal milk secretion between the primiparas and the multiparas. However, there was a significant increase in the amount of maternal milk secretion in the breast feeding group compared to the supplementary feeding group from the second to the sixth day of the puerperium (p<0.005). Moreover, the amount of maternal milk secretion increased significantly in the group that adopted the rooming-in system compared to the non rooming-in group (p<0.005). And also the significant increase occured in the encouragement of breast feeding following the adoption of the rooming-in system (X^2=7,244, p<0.01). There was no significant correlation between the amount of maternal milk secretion and the puerperal maternal prolactin levels, but the maternal serum prolactin level at 24 hours after delivery was significantly higher in the breast feeding group than in the supplementary feeding group (p<0.01). Also, the matemal serum prolactin was increased by the stimulation of the baby crying the same as by suckling or mannual expression. These facts suggest that the maternal-infant bonding plays the important role in the encouragement of the breast feeding and the maternal serum prolactin may have some actions on thr mechanism of maternal milk secretion.