Keewan Kim

BACKGROUND: Caffeine is the most frequently used psychoactive substance in the United States and >90% of reproductive-age women report some amount of intake daily. Despite biological plausibility, previous studies on caffeine and fecundabil…

OBJECTIVE: This study aimed to examine whether prenatal low-dose aspirin (LDA) therapy affects risk of cesarean versus vaginal delivery. STUDY DESIGN: This study is a secondary analysis of the randomized clinical effects of aspirin in gest…

CONTEXT: Diets high in plant-based protein have gained popularity due to increasing health concerns regarding consumption of animal products. Though links between intakes of certain protein-rich foods and reproductive disorders have been su…

STUDY QUESTION: Is preconception leukocyte telomere length associated with fecundability, pregnancy loss and live birth among women attempting natural conception with a history of 1-2 prior pregnancy losses? SUMMARY ANSWER: Preconception l…

BACKGROUND: It has been suggested that premenstrual syndrome (PMS) may derive from either elevated oxidative stress or reduced antioxidant vitamin levels in the body; however, these relationships have been minimally studied in a large cohor…

Evolutionary theory suggests that some animal species may experience shifts in their offspring sex ratio in response to maternal health and environmental conditions, and in some unfavorable conditions, females may be less likely to bear son…

OBJECTIVE: To characterize variation in circulating vascular endothelial growth factor (VEGF) and its receptor, soluble fms-like tyrosine kinase-1 (sFLT-1), across the menstrual cycle in normal ovulating women in relation to reproductive ho…

BACKGROUND: Riboflavin, vitamin B-6, and vitamin B-12 are key players in one-carbon metabolism as enzymatic cofactors, and deficiency of these nutrients may influence reproductive outcomes possibly through affecting reproductive hormones. …

Several autoimmune conditions have adverse effects on reproductive outcomes, but the relationship between family history of autoimmune disease in women without these conditions and pregnancy is uncertain. The objective of this study was to …

Anti-müllerian hormone (AMH) is an established marker of ovarian reserve that decreases with age. Though the pool of ovarian follicles is established during fetal development, impacts of in utero exposures on AMH are uncertain. Thus, we sou…

OBJECTIVE: To prospectively investigate the association of selective serotonin reuptake inhibitor (SSRI) exposure through critical windows of pregnancy establishment with fecundability and pregnancy loss. DESIGN: Prospective cohort study u…

RESEARCH QUESTION: Is a mixture of preconception serum lipids and lipophilic micronutrients associated with clinical pregnancy and live births? DESIGN: In this prospective cohort study, blood serum was collected on the day of oocyte retrie…

BACKGROUND: Vitamin D deficiency during pregnancy is associated with adverse pregnancy outcomes, although the association between preconception vitamin D concentrations and livebirth is unknown. We aimed to assess the association between pr…

Concerns remain about the health of children conceived by infertility treatment. Studies to date have predominantly not identified substantial long-term health effects after accounting for plurality, which is reassuring given the increasing…

Although minerals are linked to several reproductive outcomes, it is unknown whether dietary minerals are associated with ovulatory function. We hypothesised that low intakes of minerals would be associated with an increased risk of anovula…

OBJECTIVE: To assess the reproductive and neonatal outcomes of cycles in which donor oocyte embryos were transferred to gestational carriers compared to intended parent recipients. DESIGN: Retrospective cohort study. SETTING: Not applicab…

CONTEXT: Fatty acids (FAs) are important for reproductive processes, including steroidogenesis, though associations with fecundability, as measured by time to pregnancy (TTP), are unclear. OBJECTIVE: To investigate the relationship between…

BACKGROUND: Prior studies have reported mixed results regarding relationships between vitamin D, androgens, and sex hormone-binding globulin in patients with polycystic ovary syndrome. However, less is known regarding these associations in …

PURPOSE: Follicular redox balance is likely to be important for embryo quality during in vitro fertilization (IVF), and the anti-oxidative high desity lipoprotein (HDL) particle is the sole lipoprotein measured in follicular fluid (FF). The…

The importance of high-density lipoprotein (HDL) particle components to reproduction is increasingly recognized, including the constituent paraoxonase 1 (PON1). However, the reliability characteristics of PON1 enzymes in ovarian follicular …

BACKGROUND: Dairy food intake has been associated with infertility; however, little is known with regard to associations with reproductive hormones or anovulation. OBJECTIVE: We investigated whether intakes of dairy foods and specific nutr…

BACKGROUND: Overt thyroid dysfunction has been associated with adverse obstetric outcomes. However, less is known regarding subclinical hypothyroidism or thyroid autoimmunity and their relationship to pregnancy complications. OBJECTIVE: Th…

OBJECTIVE: To assess the variability of follicular fluid (FF) high-density lipoprotein (HDL) particle components. DESIGN: Cross-sectional design with assessment using two-stage nested analysis of variance. SETTING: Reproductive health cen…