M Mubashar Anwar

Hassan Amin

Mashhood Tabusum

Age Determination of Fetus

Difference between Fetus & EmbryoWhy It is requiredDifferent MethodPreferred MethodAdvantages of its

Key Points

The embryo is defined as the developing pregnancy from the time of fertilization until the end of the eighth week of gestation.

Fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.

Embryo & Fetus

Cont…

One question may arise in your mind that why we determine the age of fetus & embryo??

Why????

For the determination of age of fetus and embryo, generally there are two methods and these are

Ultrasound Method Rectal Examination Method

Methods

It is a method used for the determination of fetus and embryo

This method is used for the diagnosis of disease

Ultrasound Method

It is a method which is used to determine the age of embryo or fetus with the help of hand.

During rectal examination of animal we focus on the following points in order to determine the exact age of embryo or fetus

Diameter of Amniotic VesicleDiameter of PlacentomesDiameter of Horn containing the fetusAmount of Fetal FluidWeight of FetusDiameter of uterine Artery

Rectal Examination

From the above methods we preferred the first two method i.e.

Diameter of Amniotic VesicleDiameter of Placentomes

Cont…

A thin, tough, membranous sac that encloses the embryo or fetus of a mammal, bird, or reptile is called Amniotic Vesicle.

It is filled with a serous fluid in which the embryo or fetus is suspended.

In this method we determine the diameter of amniotic vesicle by using our hands.

The data regarding size of amniotic vesicle is given below.

Diameter of Amniotic Vesicle

Days of Gestation Diameter of Amniotic Vesicle

30 1.0 cm (Pea Size)

40 2.5-3.0 cm (Size of Plum)

50 3.5-5.0 cm

60 6-7.5 cm

70

80

90

120

150

180

210

240

The whole group of fetal and maternal tissues that are involved in placentation is called Placentomes.

In this method we determine the diameter of placentomes by using our hand.

Diameter of Placentomes

Day of Gestation

Diameter of Placentomes

30

40

50

60

70 0.5-0.75 cm

80 0.5-1.0 cm

90 1.0-1.5 cm

120 1.5-2.5 cm

150 2.5-4.0 cm

180 4.0-5.0 cm

210 5.0-7.5 cm

240 6.0-9.0 cm

270 8.0-12 cm

Days of Gestation Diameter of Horn Containing the fetus

30 2-4 cm

40 3-6 cm

50 5-7 cm

60 6-9 cm

70 7-10 cm

80 9-12 cm

90 10-13 cm

120 12.5-18 cm

150 18-23 cm

180

210

240

270

Diameter of Horn containing Fetus

Day of Gestation Amount of Fetal Fluid30 30-60 ml

40 75-100 ml

50 90-200 ml

60 200-450 ml

70 350-650 ml

80 500-800 ml

90 750-1400 ml

120 2000-3500 ml

150 4000-5000 ml

180 4000-7500 ml

210 6300-10,000 ml

240 8000-12000 ml

270 12,000-20,000 ml

Amount of Fetal Fluid

Day of Gestation Weight of Fetus30 0.3-0.5 gm

40 1-1.5 gm

50 3-6 gm

60 8-30 gm

70 25-100 gm

80 120-200 gm

90 200-400 gm

120 1000-2000 gm

150 3000-4000 gm

180 5-10 kg

210 8-18 kg

240 15-25 kg

270 20-25 kg

Weight of Fetus

Days of Gestation

Diameter of Uterine Artery

30

40

50

60

70

80

90 0.3-0.5 cm

120 0.5-0.8 cm

150 0.6-1.0 cm

180 0.9-1.25 cm

210 1.25-1.5 cm

240 1.25-1.7 cm

270 1.5-1.9 cm

Diameter of Uterine Artery

This method isCheap methodEasy

Animal feel pain while practicing this method.During this method chances of bursting of

amniotic fluid increases.

Cont…