Fetus development and size
The stage of prebirth development from nine weeks of gestation to birth. The organ systems and major structures take form during the EMBRYO stage, which encompasses the second to the eighth weeks of gestation. During the fetal stage, which is 32 weeks in a full-term PREGNANCY, the systems, organs, and structures grow and develop further sophistication in preparation for independent life. The fetus reaches viability (possibility of surviving on its own) at around 24 weeks of gestation.
| HIGHLIGHTS OF FETAL GROWTH | ||
|---|---|---|
| Fetal Age (Gestational Weeks) | Fetal Size | Key Developments |
| 14 | 3 inches in length | face clearly formed LIVER produces erythrocytes |
| 18 | 6 inches in length | lanugo (fine HAIR) on head movement may be detectable sucking gastrointestinal tract produces meconium |
| 24 | 11 inches in length one pound in weight |
viability possible with intensive medical care movement apparent eyebrows and eyelashes fingerprints and footprints heartbeat detectable with stethoscope gender detectable with ULTRASOUND startle REFLEX |
| 28 | 15 inches in length two to three pounds in weight |
viability possible eyelids open and close increasing level of BRAIN and NERVOUS SYSTEM functions alveoli in LUNGS |
| 32 | 17 inches in length four pounds in weight |
viability probable body fat BREATHING movements in lungs |
| 36 | 19 inches in length five to six pounds in weight |
viability likely fingernails completely cover fingertips head hair replaces lanugo on head |
| 40 | 20 to 21 inches in length seven to eight pounds in weight |
viable, full term body lanugo disappears lungs mature |
See also ABORTION; CHILDBIRTH; CONCEPTION; FETAL ALCOHOL SYNDROME; PRENATAL CARE; STILLBIRTH.
