Secondly, there was no standard questionnaire for this type of study therefore some data might be incomplete. Thirdly, exercise and dairy diet were roughly evaluated. Furthermore these were still many other contributing factors that should be collected for analysis such as self baby care, weight reduction course. However we hope that our data of the postpartum weight retention will lead to the future guideline of obstetricians to control the postpartum weight. In conclusion, mean weight retention at sixth weeks postpartum in Thai singleton pregnancy with normal pre-pregnancy BMI was 4.99 ± 4.03 kg. The recommendation for the optimal gestational weight gain, absolute breastfeeding and the appropriate nutrition after delivery and the suggestion of weight reduction at postpartum visit is the important issues which the obstetricians should concern.