Lifestyle and Fertility Study on Antioxidant Status, Diet and Early Pregnancy

Only one-fourth to one-third of fertilized human eggs are likely to survive to produce a
term baby. The causes of these reproductive failures are substantially unknown, but
scientific evidence suggests that they may, in part, be due to exposures such as
pre-conception nutrition, that may result in insults to the oocyte and periconceptual
embryo. Early reproductive events may have long-lasting impact as several have recently been
identified as antecedents to adult-onset diseases. The goal of this prospective
epidemiologic study is to evaluate the hypothesis that increased oxidative stress results in
delayed time-to-pregnancy or early pregnancy loss. Recently, reactive oxygen species (ROS)
have been associated with spontaneous abortion, preeclampsia, and premature preterm rupture
of the membranes in women and defective sperm function in men. In living cells ROS are
formed continuously as a consequence of both biochemical reactions and external factors. In
this prospective cohort study of healthy couples who are planning pregnancy, we are
evaluating time-to-pregnancy, defined as the number of menstrual cycles from the cessation
of contraception to a clinically recognized pregnancy, and early unrecognized pregnancy
loss. Unrecognized pregnancy and subsequent early loss will be determined by measuring
urinary human chorionic gonadotropin (hCG). Diet will be assessed in both partners prior to
conception using the Block food frequency questionnaire and serum assays for the
antioxidants vitamins C and E, the carotenoids, and selenium. Two urinary biomarkers of
oxidative stress, 8-hydroxy-2'-deoxyguanosine and F2a-isoprostanes, and a serum biomarker of
antioxidative capacity, oxygen radical absorbance capacity, will be measured in the women.
The proposed study has a number of strengths: 1) it is large and prospective in design, with
diet and oxidative stress measured prior to conception; 2) a highly sensitive and specific
assay for hCG will be used to detect conceptions as early as the time of implantation; 3)
dietary intake and biomarker assays of antioxidant status will be assessed twice during the
preconception period using state-of-the-art assessment methods including a diet calibration
substudy; 4) the proposed research has the potential to fill gaps in our understanding of
the role of diet in achieving successful conception, an area where very little investigation
has been done.

Inclusion Criteria:

- Female is between 18 and 39 years of age

- Female is having regular periods

- Couple is currently using some form of contraception (e.g., oral contraceptives,
barrier methods, timing method), but planning to get pregnant in the near future.

Exclusion Criteria:

- Female has a previous pregnancy

- Female has tried for 12 months or more to achieve a pregnancy without success, or has
undergone fertility treatment

- Female has received a diagnosis of polycystic ovary syndrome (PCOS)

- Female has another serious medical condition (e.g. heart disease, kidney disease,
diabetes, thyroid disease, clinical depression, or an acute chronic infection)

- Male has tried for 12 months or more to achieve a conception without success

- Male has had a fertility related condition (e.g., zoo- or oligospermia, other
abnormal semen analysis, cryptorchidism, or testicular cancer)

- Male has another serious medical condition (e.g. heart disease, kidney disease,
diabetes, thyroid disease, clinical depression, or an acute chronic infection)