The majority of American women become aware of pregnancy ~3-7 weeks after conception, and all must seek testing to confirm their pregnant status. The delay between conception and awareness is often a time in which contraindicated behaviors take place. However, there is long standing evidence that passive, early pregnancy detection may be possible using body temperature. To address this possibility, we analyzed 30 individuals continuous distal body temperature (DBT) in the 180 days surrounding self-reported conception in comparison to self-reported pregnancy confirmation. Features of DBT nightly maxima changed rapidly following self-reported conception, reaching uniquely elevated values after a median of 5.5 +/- 3.5 days, whereas individuals reported a positive pregnancy test result at a median of 14.5 +/- 4.2 days. Together, we were able to generate a retrospective, hypothetical alert a median of 9 +/- 3.9 days prior to the date at which individuals received a positive pregnancy test. Continuous temperature-derived features can provide early, passive indication of pregnancy onset. We propose these features for testing and refinement in clinical settings, and for exploration in large, diverse cohorts. The development of pregnancy detection using DBT may reduce the delay from conception to awareness and increase the agency of pregnant individuals.
Letter: False positive pregnancy test in uraemia.
