Matthew Cherry, 35, used a balaclava and a fake foreign accent to launch the “savage attack” at Caroline Craft’s ground-floor flat in Bournemouth, Dorset.
He punched her in the stomach and back, targeting her unborn child and leaving her “bloodied and bruised”, but she was not seriously harmed and gave birth to a boy – now 15 months old.
Cherry was angry and upset that Miss Craft, 27, also a police officer, would not have an abortion and the pair split up, Winchester Crown Court heard.
Cherry, now living in Southampton, denied attempting to cause grievous bodily harm with intent in March last year. But the jury rejected his claim that he was was several miles away at the time.
Miss Craft was six months pregnant when she answered the door to a masked attacker on March 24, thinking it was an estate agent.
Matthew Jewell, prosecuting, said the attack only ended because the estate agent turned up and Cherry fled, using a back door as he knew the block well and had once owned the flat.
Cherry was linked to the crime by a jigsaw puzzle of evidence that presented a “compelling picture” that he was the attacker who carried out the “savage attack” and the jury of five women and seven men agreed.
He had told Miss Craft and her flatmate Carla Hutchings that he had thought about punching her to cause a miscarriage.
He said the pregnancy had left him feeling “trapped” and had “ruined his life”. He even discussed with a police colleague how to bring on a miscarriage.
He told the jury that he did not love Miss Craft and was only fond of her.
Footwear impressions were found at the scene and were found to match a pair of Nike Dart trainers that Cherry admitted he once owned but claimed to have thrown away. Cherry’s mobile phone was also tracked to the the route the hooded attacker took when he fled.