Understanding Pregnancy Loss in the Context of Abortion Restrictions and Fetal Harm Laws
| Appendix A: Brief Timeline of Cardiac Development | |
| Gestational Age (GA) | Description |
| ~5 weeks GA | The embryo’s developing heart is tubular in shape, and called a primitive heart tube. At this time, this collection of cells develops spontaneous cardiac activity, typically detectable after 6 weeks gestational age. |
| ~10 weeks GA | The heart’s shape now resembles a developed heart with four chambers. It does not yet function as a developed heart. |
| ~22 weeks GA | The heart beings to function as an organized muscle. The direction and function of fetal blood flow is still very different from that of a newborn’s. |
| At delivery | The cardiovascular system of the fetus goes through a dramatic series of structural and functional changes.The newborn’s heart, lungs and blood flow only now resembles that of a child or an adult. |
| NOTES: Most research on the topic of human development/embryology will discuss timelines in terms of embryonic/fertilization age (time since fertilization). For consistency, however, we refer to all points in pregnancy by the gestational age (time since last menstrual period). There is approximately a two week difference between gestational age and fertilization age, and different sources may use different units of measurement. | |
| Appendix B: Multiple Terms Are Used To Describe Pregnancy Loss And Early Infant Death | |||
| <13 weeks GA | 13-20 weeks GA | ≥ 20 weeks GA to delivery | After Delivery |
| Early pregnancy loss | Early second trimester pregnancy loss |
Stillbirth* |
Neonatal death (<28 days old)
Infant death (<1 year old)
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Spontaneous abortion |
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| Miscarriage (as used in lay press and policy) | |||
| NOTES: GA = gestational age, calculated as time since the first day of the last menstrual period (LMP). *In clinical practice, stillbirth may refer to pregnancy loss after 28 weeks rather than 20 weeks depending on the practice setting. A late IUFD refers to pregnancy loss after 28 weeks. SOURCES: ACOG Practice Bulletins: Early Pregnancy Loss and Stillbirth; UpToDate articles: Miscarriage and Stillbirth |
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