• Journal of Embryo Transfer
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• v.24 no.1
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• pp.15-19
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• 2009

This study was carried out to collect the basic data about gestation lengths and offspring's birth weights and sex ratio of the dairy recipients transferred with Hanwoo IVF embryos. Blastocysts cultured for $7{\sim}8$ days were transferred to 96 and 167 heads for the basic data about gestation length and offspring's birth weight and sex ratio of the dairy recipients, respectively. The gestation lengths of the dairy recipients transferred with Hanwoo IVF embryos were $287.3{\pm}11.2$ ($257{\sim}311$) and $284.1{\sim}7.7$ ($266{\sim}295$) days in male and female of the offspring, respectively. The gestation lengths of the recipients were $290.7{\pm}10.4$, $285.8{\pm}3.4$, $280.0{\pm}9.3$ and $286.1{\pm}7.9$ days in spring, summer, autumn and winter of the calving season, respectively, and were significantly different among the calving season (p<0.05). The birth weights of male and female calves were $25.5{\pm}2.4$ ($21{\sim}30$) and $26.3{\pm}3.9$ ($21{\sim}40$ kg in offsprings of the dairy recipients transferred with Hanwoo IVF embryos, respectively. The sex ratio was 90.7 in the offsprings of the dairy recipients transferred with Hanwoo IVF embryos.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.365-373
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• 2009

Since 1990, identifying the sex of fetus and illegal abortion has brought the sex ratio imbalance at birth in Korea due to a notion of preferring a son to a daughter, socio-economic development, population policy, and so forth. Although there have been many researches such as time series analysis and region difference analysis to monitor this sex ratio imbalance, they have a defect that time and space could not be included in the analysis simultaneously. This study analyzes the sex ratio imbalance at birth, taking into account time and region at the same time. The analysis considered the numbers of male and female babies, who were born as the third or latter in their families, in 2000 and 2001 at 234 Gu / Si / Goon administrative districts. Here, we suggest a mixture model of binomial distributions, assuming heterogeneous populations. The estimation of the location parameters, weights and correlation coefficient of the mixture model is conducted by the EM algorithm, and the heterogeneity of the regions is expressed as a picture using ArcView GIS.

• The Korean Journal of Health Service Management
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• v.8 no.3
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• pp.137-145
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• 2014

The objective of this study was to analyze the risk of preterm birth (PTB) and low birth weight (LBW) in extramarital birth by analyzing 2008-2012 birth certificated data (2,328,719 births) from Korea Statistics. Odds ratio and 95% confidence intervals (95% CI) were calculated from logistic regression analyses to describe the associations between PTB & LBW and extramarital birth adjusted for maternal age, maternal occupation & education, infantile sex, birth order and number of child birth (singleton & multiple birth). The rate of extramarital birth was 1.8 percent and 2.1 percent in 2010-11. The incidence of LBW was 8.1 percent in extramarital birth and 5.0 percent in marital birth. The incidence of PTB in extramarital birth were 8.2 percent and 5.8 percent in marital birth. Compared with marital birth, the odds ratio (OR) for PTB were 1.48 (95% CI: 1.43-1.54) for extramarital birth. Risk of LBW was higher in extramarital birth (OR: 1.70, 95% CI: 1.64-1.76) than that of marital birth. Among mothers younger than 20 years, the odds ratio of PTB among extramarital birth, relative to married birth was 1.69 (1.49-1.91). Among unmarried mothers, those at a higher risk of LBW was aged 20-29 years (1.69: 1.59-1.79). Maternal unmarried status was associated with increased risk of PTB and LBW.

• Proceedings of KHEA Conference
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• 1997.07a
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• pp.127-127
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• 1997

• Korea journal of population studies
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• v.19 no.2
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• pp.5-18
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• 1996

• The Korean Journal of Health Service Management
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• v.8 no.3
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• pp.147-155
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• 2014

The objective of the study was to analyze the regional variance of late preterm birth (LPT: 34-36 weeks) by analyzing 2008-2012 birth certificated data of seven metropolitan cities (536,984 births: primiparous singleton birth) from Korea Statistics. The odds ratio and 95% confidence intervals were calculated from multinominal logistic regression analyses to describe the regional variance of LPT adjusted for maternal and infantile variables. The highest incidence of LPT rate by region were observed in Ulsan metropolitan city (3.7 percent), and the lowest in Deajon metropolitan city (3.1 percent). After adjustment by logistic regression for infantile sex, maternal variables, there was a significant increase in the risk of late preterm birth in Ulsan metropolitan city (odds ratio: 1.21) as compared with the incidence of LPT in Deajon metropolitan city. The odds ratio of LPT by region were 1.17 in Daegu metropolitan city, 1.13 Busan metropolitan city, and 1.12 in Incheon metropolitan city. More research is required to understand the risk factors for late preterm birth in this area including socio-demographic factors, medical factors, and regional and environmental factors.

• Korea journal of population studies
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• v.16 no.2
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• pp.1-23
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• 1993

Korea fertility level has dropped since the 1960's and speed of decline has accelerated in the 1980's. In the resuls, the growth rate reached to less then 1 percent in 1990 and will be $\ulcorner$0 $\lrcorner$ percent growth in 2021. The total population will increase to 50, 586 thousand persons in 2021 then will decrease. With the rapid fertility decline the age structure of Korean population has changed : while the proportion of child population aged 0-14 is decreasing sharply, that of old-age population aged 65 and over is increasing. Because of the recent increase of sex ratio at birth, the sex structure among the young generation has been destorted; the sex ratio at age 0-4 was as high as high as 112.0 in 1990. The effects of these population phenomena on Korean society are the followings: 1) Old age dependency ratio is increasing rapidly and continuously and will be about 40.0 from the 2050's. 2) Because of the rapid decline of the number of births, the absolute number of the major labour force at age 25-34 will decrease after around 2000 and then from the 2010's become less than that in 1990. 3) Since the large fertility defferentials by womens's educational level have continued and the relation between the educational levels of mothers and children are very strong, level has dropped among higher educated women first when the average fertility level has declined in Korea, the average educational level of the children is may be expected to be relatively low and then the future productivity is will be also low, which causes the decline of 'quality of population. 4) When the high sex ratio at birth (over 110 since 1986) continues, number of brides will be short by over 20 percent from the 2010s, which will bring various kinds of social prblems. Therefore, the counter measures in concrete to relieve the heavy problems are recommended as follows: 1) The extention of the birth intervals, which helps to drop the population growth rate at the same level of number of children per women. 2) The positive supports for out-migrants, which helps to reduce the population size without any destortion of age-sex structure. 3) The defferent supports of family planning for the higher and lower classes, which helps to reduce the gaps between different ferility levels of the classes and to keep and improve the quality of population. 4)population education for both students and adults, which helps to minimize the gap between the private and public requirements.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.2
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• pp.255-260
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• 1994

Calving records of 107 heifers from two breed groups were used to identify the major factors contributing to calving difficulty (dystocia) and compare the influence of pelvic diameters, weight and height of heifers measured after breeding and before calving on dystocia. The horizontal and vertical pelvic diameters, hip height and weight of heifers were measured two months after breeding and again two months before calving. Snell transformed calving difficulty scores (0 = normal to 100 = surgical intervention) were used in analyzing the data by analysis of covariance. Body condition score of the heifer, sire birth weight of the calf, birth weight of the calf, and ratio of calf birth weight to pelvic area all had significant effects on dystocia. Calf birth weight, ratio of calf birth weight to pelvic area, and heifer's condition score were especially important. However, sex of calf did not have a significant influence on dystocia. Generally, the variables measured before calving accounted for a higher proportion of variation in dystocia than those measured after breeding. Thus, based on the relative importance of the major factors affecting dystocia, it is suggested that selection of bulls with low birth weight for breeding on normal size heifers with optimum body condition score, and well developed pelvic opening, would be effective in reducing the incidence and severity of dystocia in beef heifers.

• Korea journal of population studies
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• v.17 no.2
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• pp.77-97
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• 1994

Despite the fact that the national family planning program in korea has accomplished its primary goals of fertility reduction and universal contraceptive use, the induced abortion is still high and there has been an increasing trend in the population sex ratio at birth. It seems that the changes in the imbalance of sex ratio have originated from traditonal boy preference. This indicates that much of the current family planning program can be overhauled, so that the program quality could be better controlled, by preventing the number of unwanted pregnancies and the imbalance of sex ratios. This paper aims, therefore, to examine the determinants of induced abortion through the investigation of pregnancy outcomes and their changes over time and to study the interaction between induced abortion, boy preference and the imbalance of sex ratio in Korea. The abortion rate had increased rapidly until the mid-1980s when there were about the same number of abortions as live births. Thereafter, the abortion rate has been maintained at this high level. By parity it shows a much higher abortion rate for a higher parity at all time. From the first parity, the sex composition of previous children stands out as the most important factor in deciding the pregnancy outcome at all time. The probability of a pregnancy ending in an abortion increases substantially when parents already had a son. The decline of the desired family size and the sustained strong son preference has made the sex of children a more important factor in the determination of the pregnancy outcome. Women's education has had consistently positive effects on the probability of a pregnancy ending in an abortion, but the effect shows a steady decline over time. The premarital pregnancy and urban residence also increase the abortion probability. This study suggests that the main concerns of the family planning program should be to strengthen the social support policies so as to weaken the son preference value leading to a balanced sex ratio and prevention of induced abortions.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.169-175
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• 2018

It has been claimed that artificial insemination (AI) of cows with frozen-thawed semen treated with commercially produced kits, Wholemom (in favour of female gender) increases the birth chance of calves with desired sex ratio by approximately 85% without decrease of pregnancy rates. Hence, this study was conducted to investigate the efficacy of wholemom kits as combined with frozen-thawed bovine semen during in vitro fertilization on the in vitro fertilization and developmental efficiency and sex ratios such as some reproductive parameters in bovine. For this, 1,737 oocytes were in vitro fertilized and developed. Agglutination effects on bovine after treatment of Wholemom kit were observed by time passage and dose respectively. To determine sex of embryos, Bovine embryo Y-specific gene primers(ConEY) and Bovine specific universal primer(ConBV) were used as multiple PCR method. Fertilization rate of wholemom-treated group was significantly lower than its of control group[66.9% (1,156/1,737) in Wholemom-treated group; 75.0% (610/813) in control group]. However, developmental rate after fertilization of both wholemom-treated and control groups were not significantly different [26.1% (404/1,156) in Wholemom-treated group; 27.4% (224/610) in control group]. Sex ratio of in vitro fertilized embryo with frozen-thawed semen treated with wholemom kit was determined by multi PCR. Female ratio in wholemom-treated group [85.4% (173/201)] was significantly higher than its of control group [47.2% (66/141)]. In conclusion, wholemom treatments of semen used in the in vitro fertilization and development of bovine oocytes provided increase in female ratio with decrease of fertilization rate.