the purpose of this study was to examine the effect of self-control feedback on relative and absolute timing through observational and physical practices. participants (n=90) were randomly assigned to physical and observational practice (self-control, yoked, and instructor kr) groups. they practiced a sequential timing task, which required participants to press four keys (2, 6, 8, and 4) respec...

OBJECTIVE To survey the level of disclosure of conception method within families of children conceived by conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and to examine the factors that might influence parental attitudes and plans for disclosure. DESIGN In-depth questionnaire. SETTING Participants recruited through fertility clinics in the United Kingdom...

Background Identifying predictors of the probabilities of conception related to the timing and frequency of intercourse in the menstrual cycle is essential for couples attempting pregnancy, users of natural family planning methods, and clinicians diagnosing for possible causes of infertility. The aim of this study is to estimate the days in which the likelihood of conception happened by using f...

BACKGROUND Various studies have identified risk factors associated with decreased breastfeeding duration. The aim of this study was to investigate whether there is an association between oral contraceptive (OC) use before pregnancy and breastfeeding duration. METHODS In 1994/95, as part of a 3-year epidemiologic follow-up study of school children, reproductive interviews were conducted with t...

We look at whether women's status and autonomy affect birth-to-conception intervals using data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines. We followed 1123 married, fecund women, aged 25-49, for up to 5 years. In a 1994-1995 survey, women were asked about the timing of their last birth. In 1998-2000, women were asked about any pregnancies since the 1994-19...

background: the timing of maternal weight change in pregnancy may be an important determinant of birth weight. the objective of this study was to measure weight gain patterns from early pregnancy until delivery, and to examine the relationship between prenatal weight gain and low birth weight.   methods: a total of 500 pregnant women within 15-20 days of conception, with confirmed pregnancies a...

This article considers methodology for hierarchical functional data analysis, motivated by studies of reproductive hormone profiles in the menstrual cycle. Current methods standardize the cycle lengths and ignore the timing of ovulation within the cycle, both of which are biologically informative. Methods are needed that avoid standardization, while flexibly incorporating information on covaria...

Family formation changed dramatically over the twentieth century in the United States. The impact of these changes on childbearing has primarily been studied in terms of nonmarital fertility. However, changes in family formation behavior also have implications for fertility within marriage. We use data from ten fertility surveys to describe changes in the timing of marital childbearing from the...

Family formation changed dramatically over the 20th century in the United States. The impact of these changes on childbearing has primarily been studied in terms of nonmarital fertility. However, changes in family formation behavior also have implications for fertility within marriage. The authors used data from 10 fertility surveys to describe changes in the timing of marital childbearing from...