<![CDATA[Background: Pregnancy is a process of metamorphosis or development in life. The fetus grows much faster in the third trimester of pregnancy. Hunger during this period can inhibit growth until the baby is born smaller than it should be. Low hemoglobin (Hb) levels in pregnant women are one of the health disorders that can occur during pregnancy. Anemia in pregnancy is indicated if the hemoglobin level is less than 10 g/dl. The nutritional status of the mother before and during pregnancy can affect the development of the fetus at the time of conception. If the mother's nutritional status is normal before and during pregnancy, she will most likely give birth to a healthy full-term baby with normal weight. Purpose: To determine the relationship between hemoglobin levels, upper arm circumference and maternal age with the baby's birth weight. Method: Quantitative research using percentage calculations, mean square, and statistical calculations, was conducted at Baki Health Center in December 2023-February 2024. Sampling using purposive sampling, obtained a sample size of 41 respondents. Data analysis used univariate and bivariate analysis with the Spearman Rank correlation statistical test. Results: Mothers aged 20-35 years had babies with normal birth weight as many as 36 (94.7%) and p value 0.043. Normal maternal Hb levels also obtained normal birth weight as many as 37 (97.3%) with p value 0.000 and normal MUAC obtained normal birth weight as many as 21 (52.3%) with p value 0.025. The results of the statistical correlation test of all variables <0.05, so there is a significant relationship to birth weight. Conclusion: There is a relationship between hemoglobin levels, upper arm circumference, and maternal age with birth weight. Keywords: Birth Weight; Hemoglobin Level (Hb); Maternal Age; Mid-Upper Arm Circumference (MUAC). Pendahuluan: Kehamilan merupakan metamorphosis atau proses perkembangan pada kehidupan. Janin tumbuh jauh lebih cepat pada saat kehamilan trimester ketiga. Kelaparan selama periode ini dapat menghambat pertumbuhan sampai bayi lahir lebih kecil dari yang seharusnya. Kadar hemoglobin (Hb) yang rendah pada ibu hamil merupakan salah satu gangguan kesehatan yang dapat terjadi pada masa kehamilan. Anemia selama kehamilan diindikasikan jika konsentrasi hemoglobin kurang dari 10 g/dl. Status gizi ibu sebelum dan selama hamil dapat memengaruhi perkembangan janin pada saat pembuahan. Jika status gizi ibu normal sebelum dan selama kehamilan, kemungkinan besar ia akan melahirkan bayi cukup bulan yang sehat dengan berat badan normal. Tujuan: Untuk mengetahui hubungan kadar hemoglobin, lingkar lengan atas, dan usia ibu hamil dengan berat badan lahir bayi. Metode: Penelitian kuantitatif menggunakan perhitungan persentase, rata-rata kuadrat, dan perhitungan statistik, dilakukan di Puskesmas Baki pada bulan Desember 2023-Februari 2024. Pengambilan sampel menggunakan purposive sampling, didapatkan total sampel sebanyak 41 responden. Analisa data yang digunakan adalah analisis univariat dan bivariat dengan uji statistik korelasi Rank Spearman. Hasil: Usia ibu 20-35 memiliki bayi dengan berat badan lahir yang normal sebanyak 36 (94.7%) dan p-value 0.043. Kadar Hb ibu yang normal juga menunjukkan berat badan bayi lahir normal sebanyak 37 (97.3%) dengan p-value 0.000 dan LILA yang normal menghasilkan berat badan bayi yang normal juga sebanyak 21 (52.3%) dengan p-value 0.025. Hasil uji statistik korelasi seluruh variabel <0.05, sehingga terdapat hubungan yang signifikan terhadap berat badan bayi lahir. Simpulan: Terdapat hubungan antara kadar Hb, LILA, dan usia ibu hamil dengan berat badan bayi lahir. Kata Kunci: Berat Bayi Lahir; Kadar Hemoglobin (Hb); Lingkar Lengan Atas (LILA); Usia Ibu.]]>
