Lawmakers in Virginia approved Wednesday a watered-down version of a highly contested bill requiring women in the eastern US state to undergo an ultrasound prior to an abortion.

By a 65-32 vote, the Republican-dominated House of Delegates gave its green light to 11th hour revisions proposed by Governor Bob McDonnell to tame a national uproar over the so-called "informed consent" legislation.

In its original form, every woman seeking an abortion in Virginia would have to submit to a transvaginal ultrasound screening, in which a probe is inserted deep into the vagina.

The resulting image would remain in a woman's medical file for seven years, and any doctor who failed to perform a pre-abortion ultrasound would be liable to prosecution and fines.

But under pressure from pro-choice activists, as well as stinging ridicule from late-night television comics, McDonnell tweaked the bill to require only non-intrusive abdominal ultrasounds.

"It is clear that in the majority of cases, a routine external, transabdominal ultrasound is sufficient to meet the bill's stated purpose, that is, to determine gestational age," he said in a letter to lawmakers.

"Mandating an invasive procedure in order to give informed consent is not a proper role for the state," added McDonnell, a Roman Catholic father of five and a rising star in the Republican party.

"No person should be directed to undergo an invasive procedure by the state, without their consent, as a precondition to another medical procedure."

Democratic legislators tried to get a final vote on the bill postponed for a third day running, saying they needed time to look closer at the governor's amendments, but they were outnumbered by their Republican counterparts.

Woman getting ultrasound photo via Shutterstock