Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01132924 |
| Other study ID # |
999910108 |
| Secondary ID |
10-E-N108 |
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
May 5, 2010 |
| Est. completion date |
February 24, 2017 |
Study information
| Verified date |
September 2023 |
| Source |
National Institutes of Health Clinical Center (CC) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Background:
- The purpose of the 1982 1986 North Carolina Early Pregnancy Study was to determine how
often pregnancy loss occurs before women know they are pregnant. Women planning to become
pregnant were asked to collect daily urine specimens and fill out daily diaries of their
intercourse and menstrual bleeding. Researchers are interested in re-contacting this cohort
to gather new information and to examine how accurately women can recall events that occurred
earlier in their lives.
Objectives:
- To follow-up with and gather additional information from women who were involved in the
Early Pregnancy Study.
Eligibility:
- Women who participated in the 1982 1986 North Carolina Early Pregnancy Study.
Design:
- Participants will receive and complete a questionnaire that includes the following
topics:
- Their pregnancy history.
- The infant s birth, including method of delivery and induction of labor.
- Early life exposures such as their own birth weight and their parents ages at their
birth.
- Tap water use during their attempt to conceive
- General description of their behaviors during their participation in the original study,
these include: physical activity, caffeine, alcohol, and soy food consumption.
- Participants will return the surveys to the researchers in the stamped envelope provided
with the questionnaire....
Description:
We propose a follow-up study of women who participated in the North Carolina Early Pregnancy
Study (EPS) in 1982-1986. Women enrolled in the study after discontinuing birth control and
were followed for the occurrence of a pregnancy. Participants completed daily diaries and
collected first morning urine specimens which allowed the identification of menstrual cycles.
Thus each woman s time to pregnancy was prospectively measured. We intend to trace the women
and ask them to complete a questionnaire that includes their recall of their time to
pregnancy during the study. This will allow us to address two major questions, one regarding
the recall of time-to-pregnancy, and the other regarding the natural length of gestation. In
addition, we will investigate associations of bisphenal A (BPA), phthalate metabolites, 2,4-
and 2,5-dichlorophenols, Triclosan, benzophenone-3, and methyl-, propyl- and butyl-parabens
with reproductive outcomes. This is described in a separate section at the end of this
protocol because it does not involve recontacting participants, only assay of stored urine
samples for purposes within the goals of the original study.
1. Recall of time-to-pregnancy
Time to pregnancy is a commonly studied estimate of fecundability. This outcome has been
used to study the reproductive effects of environmental toxins, cigarette smoking,
obesity and numerous other exposures. Prospective studies of time to pregnancy require
enrollment of women who are just starting to attempt pregnancy and following them until
a pregnancy is conceived. This type of study can be time-consuming and costly. It is
also difficult to identify a population of women who are just beginning to attempt
pregnancy. A more efficient design is to ask women to recall their time to pregnancy.
This design is limited however, as it is unknown how well women can recall their time to
pregnancy. Only two studies have examined this question in a population with both
prospective and retrospectively recalled time to pregnancy. One of the studies involved
women from the Netherlands, the recall period was short (3-20 months), and only part of
the woman s time to pregnancy was prospectively observed. The second study had a longer
recall period (1-10 years) but included only 43 women.
2. Length of gestation
Gestational length is the time from conception to delivery. The EPS has very good data on the
first data point, and we know date of delivery. However, our data on delivery is limited by
the fact that we do not know which deliveries were induced and which were the product of
natural onset of labor and delivery. We plan to collect this information from the mothers.
Such information will not only allow us to consider the natural variability in gestational
age (a measure that does not exist at present) but also to estimate associations between
events in very early pregnancy and the subsequent duration of pregnancy. The EPS has detailed
measurements of the time from ovulation to implantation, the rate of increase in human
chorionic gonadotropin and corpus luteum rescue. To our knowledge, these early pregnancy
characteristics have not been investigated for associations with length of gestation.
