ABSTRACT
In order to ascertain prevalence rate of premarital sexual intercourse,unintended pregnancy and abortion,and evaluate associated factors of unintended pregnancy among undergraduates from all over China,the representative sample of unmarried undergraduates was obtained by using a multi-stage,stratified,probability cluster design,and data were collected by using a survey questionnaire.62 326available responders were gained.11.6％ of them acknowledged having experiences of premarital sexual intercourse (standardized prevalence rate of sexual intercourse was 13.8％).31.5％ of students active in premarital sex acknowledged undergoing unintended pregnancy.76.2％ of pregnant students selected abortion to end it.Of students active in premarital sex,46.2％ used contraception at the first sexual intercourse,28.2％ replied “always” using contraception in sexual intercourse.The rate of using condoms,oral contraceptives (OCs),and withdrawal among students who had used contraception was 52.0％,31.0％,and 27.2％ respectively.“No preparation for sex” (40.3％),“pleasure decrement” (32.1％),“won't-be-pregnancy in occasional sexual intercourse” (30.2％) were their common excuses for using no contraception.The identified risk factors for unintended pregnancy among students active in premarital sex by multivariate analysis were as follows:having no steady lover [having no steady lover vs having a steady lover:odds ratio (OR),1.875; 95％ confidence interval (CI),1.629-2.158],unaware of the course of conception (unaware vs aware:OR,2.023; 95％ CI,1.811-2.260),considering abortion not endanger women's physical and mental health (no endangerment vs endangerment:OR,2.659; 95％ CI,2.265-3.121),nonuse of contraception (never use vs always use:OR,1.682; 95％ CI,1.295-2.185).Medical students were not less likely to experience an unintended pregnancy than nonmedical students (OR,1.111; 95％ CI,0.906-1.287).The substantial proportion of unintended pregnancy among undergraduates indicates a need for convenient and targeted contraceptive education and services.
ABSTRACT
The effect of loss-of-function of Attractin (Atrn) on the male mouse reproduction system was examined in the study. The weights and pathological changes of testes and epididymes were compared between Atrn mutant (Atrnmg-3J) mice and wild-type mice (C3HeB/FeJ) at different months of age. The number and motility of sperms were measured in the mutant and control mice. Furthermore,the testicular lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in these animals were detected. The fertility potential of the sperms was observed in vivo and in vitro. The results showed that the testes of 3-month-old Atrnmg-3J mice experienced no significantly different pathological changes from the control mice at the same month of age but the SDH activity was substantially reduced. In the 5-month-old mutant mice,as compared with the control mice,mild vacuolation was found in the testes,the density and motility of sperms were decreased in the epididymes,the sperm fertility was impaired and the testicular enzyme activity was reduced. It is concluded that the age-related Atrn gene progressively loses its function and can cause testis vacuolation and impaired sperm function,which may be responsible for the impairment of male reproductive ability.