Fetal development

Fetal development

1. PRESENTED BY Ms. Flavia Dass 1 st year M.Sc. Nursing KIMS Hubli. FETAL DEVELOPMENT

2. First trimester is approximately 13 weeks. Embryonic period is roughly the period of life from 2 nd to 7 th week after fetilization . 0-2 weeks The egg is released from ovary. It is fertilized in the fallopian tube by the sperm. The fertilized egg called Zygote, differentiates into cluster of cells called Morula , an later into Blastocyst . Blastocyst implants in the endometrium of the uterus. FIRST TRIMESTER

3. At 3th weeks Neural tube ( rudiments of brain & spinal cord) Notochord ( rudiments of vertebrae) Coelomic spaces ( rudiments of body cavities) Are all developed Primitive blood cells also develop. A t 4 th week Heart starts to beat. Longitudinal & transverse folding of the embryonic disk takes place. ( longitudinal – head fold & tail fold, covert embryo from straight to curve form, transverse –folding towards the midline converts the embryo from a flat form to a cylindrical form. By the end of 4 th week the embryo has assumed its salamander look. It has rudiments of ears, arms & facial & neck structures.

4. 5 th week Rapid development of brain results in extensive growth of head & makes it much larger in relation to the rest of the body. Development take places from cephalic to caudal. Eye begin to develop with lens, vesicles, optic cups& retinal pigment. 6 th week Nose, mouth & palate begins to take form & the eyelid become visible.

5. 7 th week Extensive development of arms & legs occur with clearly defined fingers & toes. Neck region is established. Abdomen is less protuberant. Urogential development begins. By end of 7 weeks it has distinct human characteristics. By 12 th week Intestines fully into abdomen. External genitalia have male & female characteristics (not fully formed). Can swallow & make respiratory movements, urinates. Moves specific parts of limbs & open & shut mouth.

6. Second trimester is about 15 weeks i.e. 13 to 27 weeks. 4 th month (14 -17 weeks) Head growth slows, while ears move to a higher elevation on the side of the head & chin becomes evident. Eyes remain closed, body growth accelerates. Reflex responses & muscular activity begin. Sex is clearly distinguishable by 14 th week. By 16 th week bone development takes place. Average crown-rump length 11.5cm & weights between 99 to 113gms . SECOND TRIMESTER

7. 5 th month ( 18 to 20 weeks) Rapid body growth continues Leg reach their full length & toe nail develop. Eyelids remain fused. Fetus moves freely. Quickening occurs around 18 th week. The fetal hiccups & mother can feel series of slight rhythmic jerks. By the end of 5 th month vernix caseosa covers the entire body. (Vernix caseosa –mixture of sebum & epithelial cells, is a thick cheesy substance that protects the delicate skin of fetus) By the end of 5 th month average length of fetus is 16.5cms & weights 341gms.

8. 6 th month (23 -27 weeks) Hair growth is prominent. Fetus is completely covered with lanugo ( fine soft hair). Eyebrows,eyelashes & head hair are present. The skin is wrinkled, translucent & red, giving an aged appearance to the fetus. Buds for permanent teeth are present. Hands make fist. Brown fat forms ( scource of energy, heat production & heat regulation) By the end of 6 th month average length of fetus is 20cms & weights 568 gms .

9. Third trimester is approximately 13 weeks ( 28 to 16 weeks). 7 th month( 28-31 days) The fetus continues to look old & wrinkled though a little fat storage begins. The hair on the baby’s head is longer. Suckling reflex is stronger, eyes begin to open & shut. Finger nails is present. By the end of 7 th week average length is 22.5cms & weights 1023grams. Survival may be expected if born. THIRD TRIMESTER

10. 8 th month ( 32- 35 weeks) Subcutaneous fat begin to smooth out some of the wrinkles. Body begins to store fat & iron. Thick vernix caseosa covers the whole body. Hair on head continuous to grow. Lanugo is plentiful expect on face. Fingernail reaches the ends of fingers. Toe nails are present but doesn't reach the end of toes. Has control of rhythmic breathing & body temperature. The eyes are open. At the end of 8 th month average length is 27.5cms & weights 1.7kg.

11. 9 th month ( 36-40 weeks) Skin is smooth without wrinkles as the subcataneous fat becomes thicker from additional deposits. Baby is rounder, hair is larger , toe nails have reached the end of toes. Plantar creases are visible. Prominent chest & protuberant mammary gland in both sexes. Testes are in the scrotum. Lanugo has disappeared from most of the body. Skull is firm. Skin varies in color from white to pink because of melanin. By the term the average length is 31cms & weights 3.2kg.

12. THANK YOU.