武藤 はる香, 松下 充, 松本 美奈子, 神農 隆, 村越 毅, 成瀬 寛夫, 中山 理, 鳥居 裕一

Haruka MUTO, Mitsuru MATSUSHITA, Minako MATSUMOTO, Takashi SHINNO, Tsuyoshi MURAKOSHI, Hiroo NARUSE, Satoru NAKAYAMA, Yuichi TORII

聖隷浜松病院総合周産期母子医療センター産科

Division of Obstetrics and Perinatology, Maternal and Perinatal Care Center, Seirei Hamamatsu General Hospital

キーワード : Uterine arterial Doppler flow study, pulsatility index, pregnancy-induced hypertension, light-for-date infant

目的：低リスクの初産婦において，妊娠中期子宮動脈血流波形異常の頻度を明らかにし，血流波形異常とPIH発症，Light for date（LFD）児出生の関連を検討する．対象と方法：低リスクの単胎初産婦で，2009年4月から2010年4月末に妊娠中期子宮動脈血流波形測定が行われ，当科で分娩を取り扱った137例を対象として，子宮動脈血流波形とPIHの発症，LFD児出生との関連を調べた．妊娠初期リスクスコアで0‐1点のものを低リスクとし，子宮動脈のPI値はMerz Eの基準値を用いて両側の平均値が95パーセンタイル以上を高値とした．結果と考察：子宮動脈血流波形PI値上昇3例中，PIHの発症例はなく（p＝0.978），2例にLFD児を認めた（p＝0.020）．多変量ロジスティック解析では，LFD児出生に関連する因子としてPI値上昇が抽出された．PIH発症に関しては有意な項目はえられなかった．結論：低リスク単胎初産婦に対しても，妊娠中期の子宮動脈血流測定での血流波形異常の出現は，LFD児出生予測に関して有用である可能性がある．

Purpose: In high-risk pregnancies, uterine artery (UtA) Doppler flow examination has been reported to be valuable for predicting pregnancy-induced hypertension (PIH) and fetal growth restriction (FGR). However, it has scarcely been evaluated in low-risk populations. The aim of this study is to analyze the association between abnormal UtA Doppler flow and adverse pregnancy outcomes in low-risk populations. Subjects and Methods: This prospective observational study was conducted from 2009 to 2010. A total of 880 scans were obtained in the late second trimester. The inclusion criteria were as follows: (1) the neonate did not have congenital malformations; (2) the mother had a low-risk pregnancy, as determined by Japanese pregnancy risk score; and (3) the neonate was born in our institution. The UtA pulsatility index (PI) was measured on both sides, and the mean PI was calculated. An elevated UtA-PI was defined as a UtA-PI above the 95th percentile. Light-for-date (LFD) infants were defined as infants with birth weight below the 10th percentile according to Japanese standards. Statistical analysis was conducted by the χ² or Fisher’s exact tests. In addition, we performed multivariate logistic regression analysis to assess relative factors. Results and Discussion: One hundred and seventy-three women with singleton pregnancies met the inclusion criteria. Three women had an elevated PI; none of these women developed PIH (p=0.978), and two gave birth to LFD infants (p=0.020). Elevated PIs were significantly related to giving birth to LFD infants, but no such relationship was observed in connection with PIH. Multivariate logistic regression analysis showed that elevated PI was the strongest risk factor involved with giving birth to LFD infants. In contrast, no risk factor was found to be associated with PIH. Conclusion: In low-risk pregnancies, performing UtA Doppler flow velocimetry might predict LFD infants. No significant association was observed between elevated PI and PIH; this might be because there are only a few cases of PIH in low-risk populations.