During the period from the 1950s to the 1970s, if not earlier, female sterilization rates in Puerto Rico were extremely high (see e.g. "Voluntary Sterilization-A World View", Presser, Participant Journal, 1972). Various sources, including the previous one, suggest that as much as a third of women on the island had been sterilized by the early-to-mid 1970s, which was a much higher rate than the general US population and most other countries.
It is fairly straightforward to find articles or academic studies that suggest that the high rate of sterilization was primarily due to forced or coerced sterilization, as part of an intentional policy by the US government to reduce the population of Puerto Rico, if not to consolidate its control.
Indeed, Wikipedia's article on sterilization of Latinas asserts that:
Sterilization of Latinas has been practiced in the United States on women of different Latin American identities, including those from Puerto Rico and Mexico.
However, I have had trouble finding clear evidence of this (or, at least, quantifying its extent) in the Puerto Rican context. The article links to an essay in Reproduction and Society, which says the following:
Even in the textbook case of sterilization abuse that occurred in Puerto Rico, it is not always easy to distinguish voluntary from forced sterilization. Starting in the 1920s, sterilization was heavily promoted in Puerto Rico as a primary form of birth control. By 1949, 18 percent of childbirths were followed by sterilization. Between the 1930s and the 1970s, one-third of Puerto Rican women of childbearing age had been sterilized. 25 Many women welcomed the opportunity to acquire a reliable form of birth control, but their choices were limited—by the availability of cheap or free sterilization in contrast to expensive contraception; by a creative rewriting of Catholic doctrine that treated contraception as a vice but blinked at sterilization; by the fact that sterilization required no cooperation from husbands and could even be hidden from men.
The essay states affirmatively that there was sterilization abuse, but does not seek to quantify the extent of forced sterilization (and, indeed, points to to some theoretical difficulties with doing so). It also provides potential alternative explanations for the high degree of sterilization beyond governmental coercion.
Beyond this, most of the information I have been able to find comes from activist groups or academic articles with a more activist lean, which seems to mean that its reliability and sourcing leaves something to be desired. For instance, one of the most pertinent assertions is the claim, found on the website of a Chicago activist group, that a hospital had a policy of performing a tubal ligation on any woman who came in and had already had two children. Unfortunately, the claim is attributed to the Committee for Puerto Rican Decolonization, "probably" in the 1970s, and the original article is difficult to find. Further, the article attributes the account to a "trusted source," speaking for a medical student from the 1950s, thus suggesting that the information is fourth-hand at best.
Still, in the context of documented forced sterilizations of people of color, including Latina women in particular, in the United States, it is not unlikely that such a program was carried out in Puerto Rico.
So, then, to what extent was the scope of sterilization in Puerto Rico a consequence of an intentional strategy of population control by federal or local governments? To what extent was it coerced or involuntary (from physical force or surgeries without affirmative consent to deliberate misinformation, explanations of the risks or nature of the surgery given in English, misrepresentation of the benefits compared to alternative means of contraception, and so forth)?