Conceptus in the context of Pluriblast

A six-week abortion ban, also called a "fetal heartbeat bill" by proponents, is a law in the United States which makes abortion illegal as early as six weeks gestational age (two weeks after a woman's first missed period), which is when proponents claim that a "fetal heartbeat" can be detected. Many medical and reproductive health experts, including the American Medical Association and the American College of Obstetricians and Gynecologists, say that the reference to a fetal heartbeat is medically inaccurate and misleading. They note that a conceptus is not considered a fetus until eight weeks after fertilization, and that at four weeks after fertilization the embryo only has a simple tubelike structure that will later develop into a heart. Some medical professionals advise that a "true fetal heartbeat" cannot be detected until around 17 to 20 weeks of gestation when the chambers of the heart have become sufficiently developed.

Janet Porter, an anti-abortion activist from Ohio, is considered to be the person that first authored this type of legislation. Efforts to introduce her model law succeeded in passing through political branches of government in about a dozen states but in most cases the courts struck down or blocked similar legislation; however, the Texas Heartbeat Act and analogues subsequently adopted in other states succeeded due to a unique enforcement mechanism that makes challenging the law extremely difficult, and which was upheld by the Supreme Court. In some states, the heartbeat bills' effect (whether blocked or not) has been minimized by more stringent total abortion bans that were announced following the decision in Dobbs v. Jackson Women's Health Organization; in other states, such as Ohio, South Carolina and Tennessee, judges lifted the injunctions against the previously passed laws.

The fetal membranes are the four extraembryonic membranes, associated with the developing embryo, and fetus in humans and other mammals. They are the amnion, chorion, allantois, and yolk sac. The amnion and the chorion are the chorioamniotic membranes that make up the amniotic sac which surrounds and protects the embryo. The fetal membranes are four of six accessory organs developed by the conceptus that are not part of the embryo itself, the other two are the placenta, and the umbilical cord.

The allantois (/əˈlæntoʊɪs/ a-LAN-toe-iss; pl.: allantoides or allantoises) is one of the four membranes of the extraembryonic tissue arising from the yolk sac. It is a hollow sac-like structure filled with clear fluid that forms part of the developing conceptus in an amniote that helps the embryo exchange gases and handle liquid waste. The other extraembryonic membranes are the yolk sac, the amnion, and the chorion. In mammals these membranes are known as fetal membranes.

The allantois, along with the amnion, chorion, and yolk sac (other extraembryonic membranes), identify humans and other mammals, birds, and reptiles as amniotes. These extraembryonic membranes that form the embryo have aided amniotes in the transition from aquatic to terrestrial environments. Fish and amphibians are anamniotes, lacking the allantois.