But as a recent case illustrates, those contracts aren’t necessarily airtight. In January, Melissa Cook, a 47-year-old California surrogate currently pregnant with triplets, sued the commissioning father, a single 50-year-old Georgia postal worker, who wanted her to abort one of the fetuses. (The egg used to create the three embryos implanted in Cook was sourced from an anonymous, 20-something donor.) Cook, who is pro-life, filed a lawsuit in Los Angeles Superior Court, claiming California’s surrogacy law violates due process, as well as equal-protection rights guaranteed in the Constitution.

Cook says she wants to take all three fetuses to term, adopt the unwanted third, and collect her full surrogacy fee. She also wants the court to rule that her surrogacy contract is unenforceable, which would protect her from the consequences of breaching her contract and possibly allow her to keep the multi-thousand-dollar fee stipulated in her gestational carrier agreement.

“She’s trying to get the state of California, essentially, to not recognize the contract she signed,” explains Elura Nanos, a fertility attorney based in New York.

Cook’s case has its own complicated caveats, but in a broader sense, it’s far from unique: As long as people have been using third-party reproduction, they’ve been grappling with novel legal and social questions about the meaning of parenthood, and what it means to set the terms of pregnancy and childbirth in a contract.

One of the best-known examples may be the much sensationalized “Baby M” case of 1986, in which a traditional surrogate—a woman who supplies the egg and carries the intended parents’ child—demanded physical custody of the baby after giving birth, and even went so far as to kidnap the child. The contract was ultimately deemed invalid, and the baby was returned to the intended parents, with visitation rights for the surrogate. (Cook’s lawyer is the same one who represented the surrogate that carried Baby M.)

The legacy of the Baby M case is that surrogacy agencies now recommend that surrogates do not supply genetic material, and they typically only accept women who have already given birth. The underlying belief here is that such carrier candidates are less likely to get too attached to the fetus(es) they’re carrying.

But because surrogacy contracts allow someone else to mandate that a woman abort fetuses growing in her body, surrogacy is much more than a legal issue—it’s a charged bioethical and political question, too. Who are the parents of the fetuses, and who gets to make such decisions? What are the implications for women’s reproductive autonomy?

Many of the reproductive-health experts I spoke to say it’s likely—based on Cook’s age (47, older than the typical age for a surrogate) and the fact that the intended father is being sued—that the pair did not go through a scrupulous agency, or that at least they were operating under poorly worded contract. But no matter how many legal issues you iron out ahead of time, there’s no way to legislate people’s emotional responses, says Elizabeth Reis, a professor of gender and bioethics at Macaulay Honors College at the City University of New York. “Yes, sure, you can sign,” Reis says. “But there’s no way to know how you’ll feel when you’re pregnant and ordered to reduce.”