Di Indonesia, pertambahan berat badan selama kehamilan umumnya rendah (<10 >kg), padahal pertambahan berat badan tersebut merupakan indikator pertubuhan janin yang penting. Di Kabupaten Bogor, prevalensi ibu hamil penderita Kurang Energi Kronis (27,6%) adalah tinggi. Penelitian ini bertujuan mengetahui pertambahan berat badan selama kehamilan dan hubungannya dengan berat badan bayi baru lahir. Penelitian dengan disain potong lintang ini dilakukan pada 270 sampel ibu hamil yang melahirkan cukup bulan (>37 minggu), mengunakan metoda Regresi Logistik. Ditemukan proporsi bayi lahir dengan berat 2.500-2.999 gram adalah 47,8%. Rata-rata berat lahir adalah 3.015 gram. Proporsi ibu dengan pertambahan berat badan selama kehamilan 48,9%. Rata-rata pertambahan berat badan selama kehamilan sebesar 9,1 kg. Variabel yang berhubungan secara bermakna bermakna dengan berat lahir adalah pertambahan berat badan selama kehamilan (nilai p = 0,000, OR = 7,28, CI 95%= 4,25-1,46), dan asupan energi (nilai p = 0,000, OR = 5,15, CI 95% = 2,976-8,913). Juga ditemukan interaksi antara asupan energi dengan pertambahan berat badan selama kehamilan. In Indonesia, body weight gain among pregnant mother is low (kg), even the body weight gain is an important indicator for embryo growth. In district of Bogor, the prevalent of pregnant mother who safer from chronic energy deficiency (27.6%) is high. The objective of this study is to know the mean of body weight gain among pregnant mother during the pregnancy and its relationship with the newborn weight. The study design used is cross sectional study with sample size of 270 pregnant mother who delivered during gestation period more than 37 weeks. Analysis method used in this study is multiple regression method. The study result shows the proportion of 2,500-2,999 gram baby weight is 47.8%; the mean newborn baby weight is 3,015 gram; and the proportion of mother with body weight gain during pregnancy 48.9%. The mean of mother body weight gain during pregnancy is 9.1 kg. The variables related to newborn body weight statistically significance are mother body weight gain during pregnancy period (OR = 7.28, 95% CI = 4.25-12.46) and energy intake (OR = 5.15, 95% CI = 2.976-8.913). It also pointed out the interaction between energy intake and mother body weight gain during pregnancy.