探討懷孕、昇糖指數和相關營養素與嬰兒出生體型及婦女體重變化之關係

Abstract

爲了探討懷孕、昇糖指數和相關營養素與嬰兒出生體型及婦女體重變化之相關性，本研究收集兩個長期世代追蹤資料(民91與民93世代)共289位都會區婦女之數據，從懷孕前一年最遠追蹤至產後四年；主要以電訪方式進行問卷調查，飲食部分數據由24小時飲食回憶法及回憶過去典型一天飲食而得，共收集934份飲食回憶問卷。分析發現，本研究婦女飲食中昇糖指數平均為47.81±4.15，昇糖負荷平均為129.04±50.63，昇糖負荷密度平均為64.49±12.73，而婦女的教育年數與飲食中昇糖負荷呈顯著正相關。

在本研究中，嬰兒平均出生週數為38.95±1.05週，出生身長為49.27±2.03 cm，出生體重為3237.83±475.22 g，出生頭圍34.32±1.98 cm，出生胸圍32.93±2.03 cm。若是分性別來看嬰兒出生體型，則發現男嬰之身長、體重、頭圍、胸圍皆大於女嬰。在嬰兒出生體型方面，懷孕前一年GL與嬰兒出生身長呈顯著正相關；懷孕中期GL在控制性別及孕期體重增加量後，與嬰兒出生身長和體重呈顯著正相關性；懷孕中期GL密度在控制性別及孕期體重增加量後，會與嬰兒出生身長、體重和頭圍呈顯著正相關；然而懷孕全期的GI、GL和GL密度皆與嬰兒出生體型無關。在影響嬰兒出生體型的多元迴歸模式中，顯示母親懷孕全期攝取之熱量、三大營養素百分比以及GI、GL對於嬰兒出生體型影響力較小，主要還是決定於嬰兒性別、出生週數、母親未懷本胎次BMI、孕期體重增加量和父親身高等因素。

婦女至產後四年體重保留情形，在產後一個月時體重保留為4.69~5.26 kg，產後六個月保留2.14~2.44 kg，產後一年為1.04~1.81 kg，產後兩年為0.75 kg，產後三年為0.36 kg，產後四年則保留1.58 kg。在雙變項分析中，產後一年及四年體重保留皆與GI、GL、GL密度無相關性；產後一年體重保留與孕期體重增加量、產後一個月和六個月體重保留以及婦女社經背景呈正相關，但與已有子女數呈負相關；產後四年體重保留與產後六個月、一年、兩年和三年體重保留量呈正相關，而與未生本胎體重、未生本胎BMI呈負相關性。此外，多元迴歸模式中顯示，飲食中GL越高或是每公斤體重攝取之熱量(活動量指標)越少者，產後四年體重保留量也會越多；由此可知產後一年體重保留之影響因素與「懷孕」的因子較相關，而產後四年體重保留則與婦女基本資料和生活型態較相關。The objective of the study was to examine the associations between pregnancy, glycemic index (GI), the related nutrients and birth outcomes, and postpartum weight retention based on two longitudinal cohorts. Total 289 downtown women were in the follow-ups from pregnancy to the postpartum four years. Participants were interviewed mainly by telephone, and the dietary assessment was carried out by 24-hours dietary recalls and remote typical day recalls for pre-pregnancy. Total 934 24-hours dietary recalls were analyzed, and our results showed that the average dietary glycemic index was 47.81±4.15, glycemic load (GL) was 129.04±50.63, and glycemic load density was 64.49±12.73. In addition, there was a significant positive correlation between years in schools and dietary glycemic load.

In our study, the average gestational age for newborns was 38.95±1.05 weeks. The average birth length, weight, head circumference, and chest circumference of the newborns was 49.27±2.03 cm, 3237.83±475.22 g, 34.32±1.98 cm, and 32.93±2.03 cm, respectively. Furthermore, male babies were higher than female babies. Prepregnancy GL was positively correlated with birth length; after controlling for sex and gestational weight gain, GL during 2nd trimester was positively correlated with birth length and weight, as well as GL density during 2nd trimester was positively correlated with birth length, weight and head circumference; however, the entire gestational GI, GL and GL density had no correlation with birth outcomes. By multiple regression analysis, maternal entire gestational energy, energy-adjusted carbohydrate, protein, fat, GI, and GL had less influence on birth outcomes than other factors, such as sex, maternal gestational age, prepregnancy BMI, gestational weight gain, and paternal height.

Regarding maternal weight retention until four years postpartum, the average weight retention was 4.69~5.26 kg at one month postpartum, 2.14~2.44 kg at six months postpartum, 1.04~1.81 kg at one year postpartum, 0.75 kg at two years postpartum, 0.36 kg at three years postpartum, and 1.58 kg at four years postpartum. By bivariate analysis, weight retention at one and four years postpartum had no correlation with GI, GL and GL density; weight retention at one year postpartum was positively correlated with socioeconomic status, gestational weight gain, weight retention at one and at six months postpartum, but was negatively correlated with number of children. Weight retention at four years postpartum was positively correlated with weight retention at six months, one, two, and three years postpartum, but was negatively correlated with pre-pregnancy weight and BMI. Moreover, by multiple regression models, we found that dietary GL was positively correlated with weight retention, but energy consumption per kg intake was negatively correlated with weight retention at four years postpartum. These data suggested weight retention at one year postpartum had stronger relationship with ”pregnancy” per se, but for weight retention at four years postpartum, subjects’ basic background and life style factors were more influential.