| Abstract | U drugoj polovici 20. stoljeća su se dogodile mnoge kulturološke promjene koje su utjecale na živote žena. Posljedično, počela se povisivati srednja dob u kojoj rađaju djecu. Danas žene rađaju 4-5 godina kasnije nego prije 20 godina. Istovremeno se bilježi porast neplodnosti i smanjenja broja djece. U razvijenim zemljama, uključujući i Hrvatsku, zbog smanjenog broja djece dolazi do demografskog pada. Jedan od najučestalijih razloga neplodnosti je dob. Smanjenje plodnosti u prosjeku započinje u 31.godini, a 10 godina kasnije su žene neplodne. Uzrok prirodnog smanjenja plodnosti je ovarijsko starenje. To je postepeni proces smanjenja broja i kvalitete jajnih stanica. Žene se rađaju s konačnim brojem jajnih stanica koji se smanjuje kroz život. U vrijeme menarhe žene imaju oko 300-400 tisuća oocita, a do 35. godine je preostalo samo 25 000. Zajedno s padom broja folikula, smanjuje se i njihova kvaliteta. Glavni uzrok tome je porast nerazdvajanja homolognih kromosoma ili sestrinskih kromatida u mejozi zbog čega je češća aneuploidija oocita u žena starijih od 35 godina. Uzroci ovarijskog starenja su višestruki. Smatra se kako ulogu mogu imati geni, mikroklimatski uvjeti u ovarijama, bolesti ovarija i okolišni čimbenici. Dijagnostika ovarijskog starenja je dio rutinske pripreme za medicinski pomognutu oplodnju. Postoje ultrazvučna mjerenja broja antralnih folikula te volumena jajnika i protoka krvi u jajniku. Biokemijske pretrage uključuju mjerenje vrijednosti inhibina B, AMH-a i FSH-a. AMH je danas najbolji test ovarijske rezerve i starenja jer njegova razina u serumu izravno ovisi o broju malih antralnih folikula. Zbog porasta učestalosti neplodnosti, danas se u svijetu provede milijun IVF postupaka godišnje. U početku je bio slabi uspjeh IVF-a (1-5%), ali danas iznosi 50-60%. Uspješnost je najveća u žena mlađih od 30 godina. Starenjem se smanjuje uspjeh te je u 40-tima izrazito nizak. |
| Abstract (english) | In the second half of the 20th century, many cultural changes happened which impacted women's lives. Consequently, the median age at which women bore children started to increase. Today, women have children 4-5 years later than they did 20 years ago. At the same time, infertility has increased and the number of children has decreased. In developed countries (including Croatia) there is population decline due to the decreased number of children. One of the most frequent reasons for infertility is age. Decrease in fertility starts at 31 on average and 10 years later women are typically infertile. The reason for natural decrease in fertility is ovarian ageing. This is a gradual decline in the number and quality of oocytes. Women are born with a definite number of oocytes, which decreases throughout life. At the time of menarche, women have 300-400 thousand oocytes and they only have 25,000 oocytes left when they are 35 years old. Simultaneously, with the decrease in the number of follicles, there is a decrease in their quality. The main reason for this is nondisjunction of homologous chromosomes or sister chromatids during meiosis, which results in higher incidence of aneuploidy of oocytes in women over age 35. Reasons for ovarian ageing are many. It is thought that genes, microclimate in ovaries, ovarian conditions, and enviromental factors play parts in this. Diagnostics for ovarian ageing are a part of the routine preparation for medically assisted reproduction. There are ultrasound diagnostics for antral follicle count, ovarian volume, and ovarian blood stream. There are also biochemical tests for levels of inhibin B, AMH, and FSH in serum. AMH is the best test for ovarian ageing and ovarian reserve today because its level in serum is directly connected with the number of small antral follicles. Because of the increased incidence of infertility today, one million IVF procedures are conducted every year around the world. In the beginning, IVF had a low success rate (1-5%), but today it is 50-60% successful. Efficacy is the highest in women under 30 years old. Over the age of 40, the success rate is extremely low because of decreses associated with ageing. |
