She remembers the "sexual revolution" that followed the introduction of the Pill in the 60s.
"For the first time, the bonds of sex and reproduction had been broken, meaning sex was now a means of love and pleasure as well as reproduction," she says.
With this new certainty of controlled fertility many women began delaying marriage and childbirth, instead attending university and pursuing careers.
The Pill was still relatively "hush-hush" at the time, Dame Margaret says. GPs were cautious, had a medical guideline of ethics and openly prescribed it only to married women.
"I was the perfect candidate, I was young, healthy and luckily, unlike a lot of other women, I didn't have any side effects," Dame Margaret says.
"I think side effects are something one always has to think about and try to balance. You have to be open with patients about the benefits and risks of different forms of contraception."
The IUD, or intrauterine device, was introduced to New Zealand in the mid-1960s and by 1975 more than 500 women had the Dalkon Shield.
Manufacturers were forced to withdraw the product in the US as it was causing pelvic inflammatory disease, which could lead to sterility. In the US, women filed successful claims against manufacturers and some New Zealanders also tried to receive compensation.
In the 1980s, awareness of HIV and Aids saw the promotion of barrier methods increase, and campaigns promoting safer sex and condom use. In the 1990s, Depo-Provera, an early long-acting reversible contraception, given by three-monthly injections, was introduced.