| These key steps include angiogenesis and protection of the conceptus from immune responses. |
| Thus the difference in susceptibility to RDS in premature singletons and multiples may depend on the size of the conceptus. |
| And indeed biologists tend to talk about the embryo before that, as a conceptus or a pre-embryo. |
| One or more intramuscular injections of the medication usually cause resorption or spontaneous tubal abortion of the ectopic conceptus. |
| Indeed it will be several weeks before a nervous system develops that could allow the developing conceptus to feel pain or be aware. |
| But we do not suppose that this nature and plan by themselves account for the later development of the zygote and conceptus. |
