| Religion / Spiritual tradition |
Period |
| Catholicism |
Conception (but maturity 40th day after fecundation for males, 60th day after fecundation for females) |
| Protestantism |
Conception |
| Orthodoxy |
Fecundation |
| Islam |
40th day after fecundation |
| Judaism |
40th day after fecundation |
| Buddhism |
Desire of children expressed by the parents |