iii ABSTRAK Kelahiran prematur adalah kelahiran bayi kurang dari 37 minggu usia kehamilan sejak hari pertama periode menstruasi. Hal tersebut menentukan angka mortalitas dan morbiditas neonatus serta memiliki konsekuensi jangka panjang untuk kesehatan. Di samping itu, prevalensi merokok di Indonesia saat ini semakin meningkat. Oleh karena itu, hubungan antara paparan asap rokok pada ibu sewaktu hamil dengan kejadian bayi prematur perlu diteliti agar dapat dilakukan pencegahan sejak dini. Penelitian yang bersifat analitik observasional ini, dilakukan dengan menggunakan desain case-control. Sampel dari penelitian ini adalah ibu yang melahirkan bayi prematur atau yang bayinya dirawat di RSUP H. Adam Malik Medan. Metode yang digunakan dalam pengambilan sampel adalah total sampling sejak bulan Agustus-September 2013 dengan menggunakan kuesioner. Setelah data terkumpul, dilakukan uji statistik chi square. Hasil yang diperoleh sebanyak 44 sampel, terdiri atas 24 ibu yang melahirkan bayi prematur dan 20 sampel ibu dengan bayi berusia normal. Namun, terdapat 1 sampel dieksklusikan dan tidak dianalisis. Dari 43 sampel, terdapat 20 bayi prematur dan 7 bayi normal terpapar asap rokok saat di dalam kandungan, sedangkan 3 bayi prematur dan 13 bayi normal tidak terpapar asap rokok. Hasil uji chi square didapatkan p=0,000 (p<0,005), sehingga hipotesis gagal ditolak karena hasil yang didapatkan signifikan antara variabel dependen dan independen. Dari hasil penelitian tersebut, dapat disimpulkan bahwa ada hubungan yang bermakna antara paparan asap rokok pada ibu hamil dengan kejadian bayi prematur. Kata kunci: asap rokok, ibu hamil, prematur Universitas Sumatera Utara iv ABSTRACT Premature birth is the delivery of a baby with less than 37 weeks of gestation from the first day of the menstrual period. The premature delivery affects the neonate’s mortality and morbidity and also has long term health consequences on the child. Because of that, we need to determine the relationship between maternal tobacco smoke exposure during pregnancy and the occurance of premature birth. This is to ensure, that early prevention may be implemented to counteract the ever increasing prevalence of smoking in Indonesia. This research was an analytical study with cross-sectional design. The women who had premature delivery or their babies were treated in RSUP H. Adam Malik, Medan were chosen as the subjects for this study. By using total sampling method, the data from samples chosen was collected starting August till September 2013 using a prepared questionnaire. After the data was completely collected, it was analyzed using chi-square statistical test. In total, there were 44 samples were gathered that consist of 24 women who gave premature birth and the remaining 20 women who gave normal birth to their child. However, there was 1 sample excluded and was not analyzed. From the collected data, there were 20 premature babies and 7 babies with normal birth, who were all exposed to tobacco smoke during their gestational period. On the other hand, there were 3 premature babies and 13 babies of normal birth who have not been exposed to tobacco smoke.. From the result of chi-square analysis it is shown that there is a significant assosiation between the independent and dependent variable of this study. It can be concluded that there is a significant assosiation between exposure of tobacco smoke during pregnancy and the occurence of premature birth. Keywords: tobacco smoke, pregnant women, premature Universitas Sumatera Utara