Fetal Age & Gender DeterminationTurki M. Alanazi

Objective Fetal sex & age determination.

End of 1st MonthI. Length: 1 cm, weight: 2.5 g.II. Eyes are seen as 2 dark spots and mouth as cleft

End of 2nd MonthI. Length: 4 cm, weight: 10 g.II. Eyes and nose recognizable, hands and feet are webbed. Anus

is seen as dark spot. Placenta is formed.

End of 3rd monthI. Length 7.5 – 10 cm.II. Limbs are well developed.III. Neck is formed.IV. Finger toes visible.

End of the 4th monthI. Sex can be recognized.

End of the 5th week I. Length 17.5 – 20 cm.II. Eye brows are absent.III. Meconium is present in the stomach.

is the earliest stool of a mammalian infant.

End of the 7th monthI. Length 35 cm.II. Weight 0.9 g – 1.2 kg.III. Nails are thick.IV. Eyelids open and papillary

membrane disappears.V. Meconium is found in the

large intestine.VI. Testes are found at external

inguinal ring.

VII.Placenta weight 350-400.

VIII. Vernix Caseosa is present.

is the waxy or cheese-like white substance found coating the skin of newborn human babies.

End of 8th month I. Length 40 cm.II. Nails reach the tip of finger.III. Left testis is present in the scrotum.IV. Placenta weight 500 g.

End of the 9th month I. Length 45 cm.II. Anterior fontanelle is closed. III. Scrotum is wrinkled and contain both testes.IV. Placenta weighs 500 g.

End of the 10th month I. Length 50-53 cm. II. Grown rump- length 30-33 cm. III. Weight 2.5 – 5 kg.IV. Lanugo absent except on shoulder.V. The center of ossification is found for lower end of femur.VI. Nails extend beyond the finger tips at the end of 40 weeks

Rule of Hasse It is a rough method of calculating the age of fetus.

I. The length of fetus is measured from crown to heel in centimeters.

II. During first 5 months of pregnancy—square root of length gives approximate age of fetus in months.

III. During the last 5 months—length in centimeter divided by 5 gives age in months.

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