Modifiable Risk Factor Score and Fecundability in a Preconception Cohort in Singapore

Abstract

ImportanceAlthough multiple modifiable risk factors have been identified for reduced fecundability (defined as lower probability of conception within a menstrual cycle), no scoring system has been established to systematically evaluate fecundability among females who are attempting to conceive.ObjectiveTo examine the association of a risk score based on 6 modifiable factors with fecundability, and to estimate the percentage reduction in incidence of nonconception if all study participants achieved a minimal risk score level.Design, Setting, and ParticipantsThis population-based cohort study obtained data from the S-PRESTO (Singapore Preconception Study of Long-Term Maternal and Child Outcomes) prospective cohort study. Females of reproductive age who were trying to conceive were enrolled from February 2015 to October 2017 and followed for 1 year, ending in November 2018. Data were analyzed from March to May 2022.ExposuresA reduced fecundability risk score was derived by giving participants 1 point for each of the following factors: unhealthy body mass index, unhealthy diet, smoking, alcohol intake, folic acid supplement nonuser, and older maternal age. Total scores ranged from 0 to 6 and were classified into 5 levels: level 1 (score of 0 or 1), level 2 (score of 2), level 3 (score of 3), level 4 (score of 4), and level 5 (score of 5 or 6).Main Outcomes and MeasuresFecundability, measured by time to conception in cycles, was analyzed using discrete-time proportional hazards models with confounder adjustment.ResultsA total of 937 females (mean [SD] age, 30.8 [3.8] years) were included, among whom 401 (42.8%) spontaneously conceived within 1 year of attempting conception; the median (IQR) number of cycles before conception was 4 (2-7). Compared with participants with a level 1 risk score, those with level 2, 3, 4, and 5 risk scores had reductions in fecundability of 31% (adjusted fecundability ratio [FR], 0.69; 95% CI, 0.54-0.88), 41% (FR, 0.59; 95% CI, 0.45-0.78), 54% (FR, 0.46; 95% CI, 0.31-0.69) and 77% (FR, 0.23; 95% CI, 0.07-0.73), respectively. Assessment of the population attributable fraction showed that all participants achieving a minimal (level 1) risk level would be associated with a reduction of 34% (95% CI, 30%-39%) in nonconception within a year.Conclusions and RelevanceResults of this study revealed the co-occurrence of multiple modifiable risk factors for lowered fecundability and a substantially higher conception rate among participants with no or minimal risk factors. The risk assessment scoring system proposed is a simple and potentially useful public health tool for mitigating risks and guiding those who are trying to conceive.

Impact of Geography and Rurality on Preconception Health Status in the United States

“…With federal protection no longer in place and abortion illegal in nearly half of all states, more unwanted pregnancies are being carried to term ( 26 ). The results of this study add to the existing literature to emphasize the need to address the concerning rates of preconception health in the United States as a whole ( 7 , 8 ), and specifically in rural areas ( 5 ). Consistent with prior literature, rural residents in our study had high rates of preconception health risks ( 27 ).…”

“…As the first composite, individual-level measurement of preconception health in the United States, our study assesses its status. Although prior studies have analyzed preconception health factors independently ( 10 , 11 ) or at a community level ( 5 ), no study has examined cumulative, individual-level risk factors. The aPHRI scores in our overall study sample, and particularly the scores found in rural areas, show the need to address preconception health issues to prevent or reduce adverse maternal health outcomes.…”

“…Both the first and third leading causes of death are linked to preconception health and are conditions that can be managed before pregnancy ( 1 – 3 ). Although prior studies in Canada ( 4 ) and Singapore ( 5 ) have used a composite index to examine preconception health risk among either their general populations ( 4 ) or those currently trying to conceive ( 5 ), studies have not examined this risk in the United States.…”