Information about genetic processes in local populations plays an important role in understanding many socio-demographic and medical problems. Studies conducted in economically developed countries show that about half of the human gene pool does not reproduce in the next generation due to the death of embryos, stillbirths, neonatal mortality and mortality before the reproductive age, celibacy and sterile marriages [1, 2]. The reproductive behavior of women mainly depends on cultural traditions and differs among representatives of different ethnic groups. As of 2013, in the Autonomous Republic of Crimea, the proportion of Crimean Tatars, whose cultural traditions were based on the Muslim religion, increased in connection with repatriation [3]. The ethnic group of Crimean Tatars is subdivided into three sub-ethnic groups: southern coastal, steppe and mountain-foothill [4]. The purpose of this research is to study the reproductive behavior of Crimean Tatar women, considering their sub-ethnic division.
The data were collected in 2013 in the women's clinic of the Crimean Republican institution "Medical Center for Serving Deported Peoples" (Simferopol). Anonymous survey of women in the post-reproductive age (from 45 to 90 years) was carried out. The questionnaire included questions about the woman's year of birth, her nationality, considering the sub-ethnos, as well as the nationality of her parents. The number of pregnancies and their outcomes were studied as well: medical and spontaneous abortions, ectopic pregnancies, the number of stillbirths and live births.
The distribution of the number of pregnancies and their outcomes in women during the reproductive period indicates statistically significant differences between sub-ethnic groups in terms of the number of pregnancies and medical abortions. In average, a Crimean Tatar woman had 3.6 pregnancies during the reproductive period (4.0 for representatives of the steppe and southern sub-ethnic groups, 2.6 for representatives of the mountain-foothills, $p <0.05$). Also, one Crimean Tatar woman on average had less than one medical abortion (1.0 in the southern and steppe, 0.65 in the mountain-foothills, $p <0.05$); 0.3 spontaneous abortions, 0.04 ectopic pregnancies, 2.7 births, 0.1 stillbirths, and 2.6 live births.
Comparison of reproductive indicators in Crimean Tatars and Slavs (Ukrainian and Russian) living in the city of Eupatoria (Autonomous Republic of Crimea) [5] revealed statistically significant differences. Thus, the gene pool of the Crimean Tatar ethnos is reproduced more fully (97%) than the gene pool of the Slavs (95%). Slavic women resorted to artificial termination of pregnancy almost twice more often (83 %) than Tatars (45 %). Ectopic pregnancies were noted only by 0.5% of Tatar women, which is 14 times less frequent than Slavic women (7 %). The percentage of artificially interrupted pregnancies among Tatars is almost 2.5 times less than among Slavs (24 and 58 %, respectively). As a result, the fraction of implemented zygotes in Tartars is twice as high as in Slavs (69% and 33%). In terms of the number of pregnancies, Slavs are almost one and a half times larger than Crimean Tatars (5.3 and 3.6, respectively), but despite the greater number of pregnancies, Slavs give birth to fewer children number than Crimean Tatars (on average, 1.8 and 2,7 children respectively). If interethnic differences in the rates of natural increase persist, the ethnic and confessional composition of the Crimean population and its gene pool may change.
The study of the reproductive behavior of Crimean Tatar women of different sub-ethnic groups revealed statistically significant differences in the number of pregnancies and medical abortions. The Crimean Tatar population of the Autonomous Republic of Crimea is characterized by expanded reproduction, in contrast to the narrowed one among the Slavic part of the population.