Legislation and laws in Iowa and elsewhere purposely misuse the term "fetus" and "heartbeat" to describe embryos at around 6 weeks, which have not developed a heart.
The Associate Press recommends that media do not use this term without qualifiers. Here's what the AP Stylebook says (current as of July 2023):
Avoid using the terms "fetal heartbeat bill," "heartbeat bill" and "six-week abortion ban" on their own without explanation as shorthand for measures that would ban most abortions once cardiac activity is detected, around the sixth week of pregnancy.
The terms are overly broad and misleading given the disagreement over details, such as what constitutes a heartbeat at varying gestational ages. In addition, none of the measures focuses on six weeks.
Advanced technology can detect a flickering as early as six weeks, when the embryo isn't yet a fetus and it has only begun forming a rudimentary heart. The American College of Obstetricians and Gynecologists says it is not accurate to call that a heartbeat. Use the term cardiac activity instead.
Do not use the term fetal cardiac activity in the context of abortions before 10 weeks gestational age.
If quoting someone using the terms "fetal heartbeat bill," "heartbeat bill" and "six-week abortion ban," enclose the terms in quotation marks and provide explanation.
Instead, on first references, use phrasing such as a measure that bans abortions except in the earliest weeks of pregnancy; or measures often referred to as "heartbeat bills" or "six-week abortion bans" (including terms used by each side of the issue). On later references, simply the anti-abortion measure, the bill, etc.
The phrase abortion ban is acceptable for headlines when necessary, but give full details high in the story.