Kaitlin Armstrong was pregnant in Costa Rica for killing pro cyclist Anna Wilson

Convicted killer Kaitlin Armstrong was reportedly pregnant when she was arrested in Costa Rica and dragged back to Texas for gunning down her love rival, according to a new bombshell court filing.

The murderess’s lawyers made the shocking claim in documents filed earlier this month asking for a new trial — arguing Armstrong might have received a lighter punishment if a jury knew she had been expecting.

Armstrong, 35, was sentenced to 90 years in prison last month for the May 2022 shooting death of rising professional cyclist Anna “Mo” Wilson in a case that sent investigators on a 43-day international hunt for the killer.

“Kaitlin has also been pregnant twice, one occasion of which was during or near the time of her arrest,” states the filing, obtained by the DailyMail.

“Considering the sentence here was for 90 years and a maximum fine, there should be no question that this mitigating evidence would have resulted in a more lenient punishment.”

The surprising argument does not suggest how far along Armstrong may have been or whether the father could have been cyclist Colin Strickland, who had a tryst with Wilson several months earlier when he and Armstrong had briefly broken up.

The former yoga teacher gunned down the 25-year-old Wilson in a jealous fit of rage after learning Wilson went swimming and to a meal with Strickland the same day.

Wilson was visiting Austin for a race, where she was among the favorites to win, when Armstrong tracked her down and shot her three times — twice in the head and once through the heart.

The documents also introduce new arguments that paint the convicted killer in a more compassionate light — but were not made during Armstrong’s two-week Austin trial.

Her lawyer did not immediately respond to The Post’s request for comment.

The filing paints her as the daughter of an alcoholic mother, whose dad abandoned her and who was the victim of sexual abuse.

“As her family struggled during her childhood, her childhood friend also recalled Kaitlin was the victim of multiple instances of (actual or attempted) sexual violence,” her lawyer wrote.

The pregnancy claim raises some suspicions, however, considering Armstrong received plastic surgery during her time on the run in Costa Rica.

She went under the knife for a $6,000 nose job and brow lift — both of which are typically not permitted for pregnant women.

Armstrong initially tried to dodge the required lab work that would detect a pregnant, but relented after her cosmetic surgeon told her it was required, the DailyMail reported.

The pregnancy angle could be another desperate attempt at freedom by Armstrong, who has repeatedly tried to avoid repercussions for the horrifying murder.

The convicted killer made a daring prison escape in October after convincing guards to escort her to a private medical appointment for a fabricated illness.

Armstrong spent months “vigorously” training in her Texas jail cell and meticulously planning her great escape — only to be caught minutes after bolting.