Introduction
Most couples have life plans that include children, as parenthood is one
of the most universally desired aims in adulthood. However, not all
couples can achieve their desires, and a proportion of them will need
medical help to solve reproductive issues. A remarkable demographic
shift in recent years has affected female fecundity, including delayed
childbearing age and changing lifestyles.(1) Estimating population-based
fecundity is important for policy improvement in healthcare as these
changes occur.
According to the International Committee for Monitoring Assisted
Reproductive Technology and the World Health Organization, infertility
is a disease of the reproductive system defined by the failure to
achieve a clinical pregnancy after 12 months or more of regular
unprotected sexual intercourse.(2) Previous studies have reported the
prevalence of infertility among different populations in China (15.5%
in women attempting to conceive and 24.9% in women at risk for
pregnancy) using the common definition of failure to conceive within the
last 12 months.(3) Time to pregnancy (TTP), which is measured as the
months or menstrual cycles from attempting to conceive until successful
pregnancy, is gaining more attention as another measure of subfecundity
or infertility.(4) In addition to
estimating the cumulative
probabilities of conception to prevent variation across different
definitions and study designs,(5) this indicator can find suitable
thresholds to determine the grades of subfertility and is more
convenient to measure the distribution of epidemiology and the study
mechanism of the biological process.(6, 7)
Using
TTP as a continuous indicator to estimate the likelihood of conception
during a certain time, this study aimed
to portray the fecundity of
couples in a representative cross-sectional population of reproductive
ages in China.
Materials
and Methods