Selected Steps in the Development of the Unborn Child

The appendices are easy to use. Appendix 1 lists the chronological development of the unborn child from the moment of conception onward, including information on how the parts of the body unfold as well as on how the child breathes, moves, learns, and develops the senses of hearing, smell and taste. Much of the data refers to the first eight weeks (the embryonic period) when the vast majority of parts of the body first appear. After this time, development consists mostly of the growth and maturation of these organs, systems and structures. The embryonic period has been studied by scientists in much greater detail than the fetal period, which begins on the 57th day of pregnancy and continues until birth. When possible, I have added information regarding developmental milestones during the fetal period. The data are organized on a week-by-week basis, with day-by-day development noted when available.

Appendix 2 rearranges some of the data from Appendix 1, listing development of the parts of the body in alphabetical order. A general category, "Prenatal Development", focuses primarily on broad changes that occur during the 3rd to the 8th weeks. Appendix 2 also includes important definitions and information on measuring methods

Appendix 3 rearranges the rest of the information from Appendix 1, focusing on the ways that the child moves in the womb and when these movement patterns begin, with the entries arranged in alphabetical order. This appendix also highlights information about prenatal learning and the development of the senses, including data on how the child might experience pain. It also contains information describing certain physiological functions such as breathing, swallowing, and squinting.

Interpreting the Appendices

Some of the information in the appendices may seem repetitive. For example, there are three separate entries in Appendix 2 saying that the eye begins to develop on day 28 after fertilization. However, since these entries come from two different sources (Moore and Sadler), the accuracy of the observation is enhanced. The development of the eye in the same time period is further confirmed by Larsen's assertion that the eyes begin their development early in the 4th week. When multiple sources confirm a finding, it is more reliable. Multiple sources are included so that readers can form their own judgment about the information.

Sometimes the sources differ and the best we can say in these cases is that the part of the body in question begins to develop over a range of time instead of on a given day. Of course, no two persons develop at exactly the same rate anyway, so that even the most highly confirmed data would not necessarily apply to an individual case.

The data presented here are not intended to be an exhaustive layout of the day-by-day development of the unborn child. Some parts of the body were not covered in the sources cited. Other information was not included in order to keep the report to a reasonable length. As a caveat, it should not be assumed that a part of the body appears for the first time on a given day unless the text says so. In all cases, however, a part of the body is present on the day indicated

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