[Preterm birth in Bulgaria--changes in aetiology and incidence in the last decade].

There is no decrease in the incidence of preterm birth in Bulgaria and in the world, despite of all the therapeutic and prophylactic efforts. The rate of prematurity in University Maternity Hospital 'Maichin dom' in the last decade has increased significantly- from 11.6% in 2003 to 17.5% in 2013. The numbers are higher than the national average due to the essence of the Hospital being a leading clinical and scientific center. Thorough analysis demonstrates significant increase in the first grade prematurity being 5.8% of all live births in 2003 and 10.2% of all live births in 2013. In fact 58% of all premature births result in first grade preterm newborn. There is no significant increase in the forth grade- severe prematurity in the last decade. We believe that this increase in preterm birth rate is due to several reasons: the success of assisted reproductive technologies, which in Bulgaria leads to a significant increase in the number of multiple pregnancies; destructive/ablative methods of treatment of cervical intraepithelial neoplasia, especially LLETZ (LEEP), postponing of first pregnancy, increase in the number of adult primiparous women and as a whole pregnancy at later age, pregnancy in puberty. All these impose changes in the protocol for pregnancy follow up. Furthermore, we believe it is high time to increase the effectiveness of this service, as lack of adequate follow up is a reason for preterm birth on its own.