ACT deputy leader Beth Houlbrooke says people who can't afford to have babies when they're young should consider waiting until they're in their late 30s or early 40s instead.
Speaking to RNZ on Friday morning, she denied that ACT's policy was to discourage poor people from having children, as she'd suggested in a previous Facebook post.
Writing on Wednesday about Labour's $60 a week baby bonus, Ms Houlbrooke said it "could extend the misery of child poverty and even child abuse", and that "parents who cannot afford to have children should not be having them".
Both she and party leader David Seymour accused Labour of "paying people to bring children into the world", when they couldn't afford to do so.
Ms Houlbrooke has now told RNZ's Morning Report there are other options for people who can't afford to have babies - such as waiting until they can.
"We've got a great opportunity with advancements that people are now able to have children right up until they're 40," she said.
"I have many friends who have put off having children until their late 30s, early 40s, and they've done it successfully."
Freezing eggs was another option, she said.
"There's no rush to have children at an early age."
Women's fertility tends to decline steadily through their 30s, speeding up from age 35. Experts say the chances of getting pregnant at 40 are a quarter what they are at 30.
Children born to older mothers are also more at risk of birth defects, genetic abnormalities and stillbirth.
At 25, it's estimated around 1 in 1200 embryos have Down's syndrome. By 35 this increases to one in 240, and by 45 it's one in 19.
And freezing eggs might not be an affordable option for low-income parents. Fertility Associates, one provider of the service, charges $275 just for the first meeting with a doctor - the cost from there runs into the thousands. Other providers Newshub looked at charged upwards of $10,000 per egg cycle.
Rather than assisting families struggling with the cost of living, Ms Houlbrooke said Labour's policy was "vote-grabbing" by ensuring the assistance would be abruptly cut off right before the next election in 2020.
Despite saying welfare "increases dependency", Ms Houlbrooke says ACT has no plans to cut existing welfare entitlements.