• Journal of Labour Economics
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• v.31 no.1
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• pp.135-162
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• 2008

This paper analyzes the impact of the mother's employment on her time investment in children's career decisions. Parental conversations with high school children and the parents' effects on children's career decisions are used as the proxies for the quantity and quality of time investment, respectively. For the empirical analysis, IV ordered-probit regressions are fitted to the KLIPS data. Other things being equal, the mother's employment does not cast any statistically significant impact on the quantity and quality of time input for children in high school. The effect of mother's employment on her time investment in children is positive for professional jobs while negative for nonprofessional jobs, but both lack the weight of statistical significance.

• Toxicological Research
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• v.17 no.4
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• pp.279-286
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• 2001

Recently, there is an increasing nationwide concern in Korea that exposure to electric and magnetic fields in the home environment may not be safe in humans. To identify possible effects of horizontally polarized magnetic fields (MF) exposure on embryo-fetal development, timed-mated female Sprague-Dawley rats (24/group) received continuous exposure to 60 Hz MF at field strengths of 0 Gauss (sham control), 50mG,833 mG, or 5000 mG. Dams received MF of sham exposures for 22hr/day on gestation days 6 through 20. Experimentally generated MF were monitored continuously througout the study. There was no evidence of maternal toxicity of developmental toxicity in any MF-exposed groups. Mean maternal body weight, organ weights, and gross findings in groups exposed to MF did not differ from those in sham control. No significant differences in fetal deaths, fetal body weight, and placental weight were observed between MF-exposed groups and sham control. External, visceral, and skeletal examination of fetuses demonstrated no significant differences in the incidence of fetal malformations between MF-exposed and sham control groups. In conclusion, exposure of pregnant Sprague-Dawley rats to 60 Hz at MF strengths up to 5000 mG during gestation day 6-20 did not produce any biologically significant effect in either dams of fetuses.

• Women's Health Nursing
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• v.15 no.2
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• pp.121-129
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• 2009

Purpose: The purpose of this study was to examine the effect of the yoga during pregnancy on the maternal weight, delivery experience and infant birth weight. Method: The nonequivalent control group pre test-post test design was used. The participants were the healthy pregnant women, whose pre-pregnancy BMI was normal, gestational period was more than 20 weeks. The final sample consisted of 21 mother-infant dyads for experimental group and 20 dyads for control group and who agreed to participate in this study. Data were collected from February I st to December 15th, 2006. The Qi exercise prenatal program was carried out for 90 minutes a day, 2 times a week for 12 weeks. The data were analyzed using SPSS 16.0 Program. Result: The degree of maternal weight gain(p<.001), labor pain(p<.001), discomfort after delivery(p<.001) and infant's birth weight(p<.00I) were significantly different between two groups. Conclusion: The yoga during pregnancy managed weight gain of mothers. Therefore, this study suggests that yoga during pregnancy to promotes stabilization can be beneficial for maintaining healthy weight, decreasing labor pain and discomfort after delivery for pregnant women and increasing infant's birth weight.

• Korean Journal of Childcare and Education
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• v.18 no.5
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• pp.33-55
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• 2022

Objective: The aims of this study is to investigate the internal and external environment surrounding fathers and to promote play-participation with children and father-Infants Intimacy by identifying the influence of a father's belief concerning gender-equal parental role and the mother's roles as a gatekeeper. Methods: The participants of this study were 291 fathers who had infants ranging from 1-36 months of age and were living in Seoul and South Chungcheong Province. The data were collected through the questionnaires and analyzed using the SPSS 24.0. Results: The main results are as follows. First, gender roles, livelihood keeper-father beliefs, importance of father rearing, and the mother's role as a doorkeeper affect the father's participation in play. This differs according to the characteristics of each type of play. Second, it was found that the father's gender roles and the mother's role as a doorkeeper had a significant effect on the intimacy between the father and the infant. Conclusion/Implications: The results of this study revealed that fathers' belief in gender-equal parenting and mothers' encouragement through opening the door as gatekeepers affect the formation of intimacy between fathers and their children in infancy, and are factors that influence play participation.

• 대한생식의학회:학술대회논문집
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• 2001.06a
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• pp.41.2-42
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• 2001

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.157-157
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• 2003

Recently we have demonstrated that a 12-day s.c. dose of 2-Bromopropane(2-BP) to pregnant mice during pregnancy resulted in significant developmental toxicity at dose levels of above 1250 mg/kg/day. However, the cause and effect relationship between maternal and developmental toxicities could not be elucidated in the previous study.(omitted)

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.12-19
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• 2008

We evaluated the relationship between birth weight and mercury exposure levels in Seoul, Korea, by following a cohort of pregnant women and the outcomes of their pregnancies between 2001-2005. Eighty-five pregnant women were recruited into this study after obtaining informed consent. Samples were collected at delivery from normal pregnant women who were living in the city of Seoul, Korea. Mercury concentrations in 85 sets of maternal and cord blood samples were measured using a gold-amalgam collection method. We used multiple regression analysis to analyze the effect of mercury exposure on birth weight. The mean levels of total mercury concentrations were 5.41(ppb) in maternal blood of pregnant women and 3.58(ppb) in umbilical cord blood. The mean concentration of umbilical cord blood mercury exposures was higher than the level recommended by WHO. There was a significant correlation between maternal and cord blood mercury concentrations. Mercury concentrations of umbilical cord blood was associated with birth weight. In addition, after adjusting for potential confounding factors, we found that mercury exposure may reduce the birth weight. This study suggests that exposure to mercury concentration during pregnancy contributes to the risk of low birth weight. Therefore, prenatal and environmental education for various and possible sources of mercury exposure might be necessary for the good health of babies. The finding of this study supports the construction of national policy for environmental health management.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.239-244
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• 2007

This study was conducted to investigate effects of weaning age on growth perforance, feed intake, disease occurrence and maternal reproductive efficiency in Hanwoo. Sixty experimental calves were allocated into two groups, early weaned (n=29, calf age 90 d, EW) and normally weaned (n=31, calf age 120 d, NW). Body weights and average daily gains during nursing and post-weaning periods were similar between two groups (p>0.05). Weaning age had no effect on calf starter, grass hay, dry matter, crude protein and TDN intakes of calves (p>0.05). Maternal calving interval in EW was shortened by 23 days compared to NW (p>0.05). Any difference in occurrence of disease was not observed between groups. Present results indicate that early weaning age has no negative effects on growth performance, feed intake or on disease occurrence in Hanwoo calves. And it has positive influence on maternal calving interval.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.3029-3034
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• 2015

Background: While the perinatal outcomes of active maternal smoking are well documented, results of the effects of environmental tobacco smoke (ETS) exposure during pregnancy are inconsistent. We aimed to examine the effect of ETS exposure, assessed by maternal hair nicotine levels at $35^{th}$ week of gestation, on birth weight and the risk of small for gestational age (SGA) and low birth weight (LBW). Materials and Methods: A total of 871 non-smoking healthy pregnant women were recruited by one Korean hospital between 1 October 2006 and 31 July 2007. Hair samples were collected and anthropometric questionnaires administered at $35^{th}$ week of gestation. The primary outcome was birth weight and secondary outcomes were the risk of babies being SGA and LBW. Results: Log-transformed hair nicotine concentrations were inversely related with birth weight after adjusting for confounding variables (${\beta}=-0.077$, p=0.037). After stratifying hair nicotine levels by tertiles (T1, low [0.0-0.28 ng/mg]; T2, medium [0.29-0.62 ng/mg]; and T3, high [0.63-5.99 ng/mg]), the mean birth weight in each groups were 3,342g (T1) 3,296g (T2) and 3,290 g (T3), respectively. However the difference between groups was not statistically significant by analysis of co-variance (ANCOVA) adjusting for covariates (p=0.062). In logistic regression analysis, the risk of SGA was higher in the T3 (OR=1.59, 95%CI 1.05-2.42) than in the reference group (T1), after controlling for confounding variables. The risk of low birth weight (<2,500g, LBW) was not significantly higher (OR=1.44, 95%CI 0.95-2.19), but the risk of babies being below 3,000g birth weight was increased in the T3 group (OR=1.53, 95%CI 1.00-2.36) compared with that in the T1 group. Conclusions: Maternal ETS exposure during pregnancy was inversely related with birth weight. The risk of SGA increased in the highest ETS exposure group compared with in the low exposure group. To prevent ETS exposure during pregnancy, more comprehensive tobacco control policies are needed.

• Toxicological Research
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• v.24 no.4
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• pp.307-314
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• 2008

The present study was carried out to investigate the potential adverse effects of 1,3-dichloro-2-propanol on pregnant dams after maternal exposure during the gestational days (GD) 6 through 19 in Sprague-Dawley rats. The tested chemical was administered orally to pregnant rats at dose levels of 0, 10, 30, or 90 mg/kg/day. During the test period, clinical signs, mortality, body weights, food consumption, serum biochemistry, gross findings, organ weights, and Caesarean section findings were examined. In the 90 mg/kg group, decreases in the body weight gain and food consumption, and increases in the weights of liver and adrenal glands were observed. Serum biochemical investigations revealed increases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholesterol (CHO), triglyceride (TG), alkaline phosphatase (ALP), and bilirubin (BIL) and decreases in glucose (GLU), albumin (ALB) and total protein (TP). In the 30 mg/kg group, a decrease in the food consumption and an increase in the liver weight were observed. Serum biochemical investigation also showed increases in CHO and TG and a decrease in glucose. Since there were no signs of maternal toxicity in the 10 mg/kg group, it is considered to be the no-observed-adverse-effect level (NOAEL) of 1,3-dichloro-2-propanol. It is concluded that successive oral administration of 1,3-dichloro- 2-propanol to pregnant rats for 14 days may cause significant toxicities in body weight and liver at a dose rate ${\geq}$ 30 mg/kg/day.