A) The Quran on Human Embryonic Development:
In the Holy Quran, God speaks about the stages of man’s embryonic development:


"We created man from an extract of clay. Then We made him as a drop in a place of
settlement, firmly fixed. Then We made the drop into an alaqah (leech, suspended
thing, and blood clot), then We made the alaqah into a mudghah (chewed
substance)..." 1 (Quran, Surah al-Mu'minun 23:12-14)

Literally, the Arabic word alaqah has three meanings: (1) leech, (2) suspended thing, and (3) blood clot.

In comparing a leech to an embryo in the alaqah stage, we find similarity between
the two2 as we can see in figure 1. Also, the embryo at this stage obtains
nourishment from the blood of the mother, similar to the leech, which feeds on
the blood of others.3



Figure 1:
Drawings illustrating the similarities in appearance between a leech and a human
embryo at the alaqah stage. (Leech drawing from Human Development as Described in the Quran and Sunnah, Moore and others, p. 37, modified from Integrated Principles of Zoology, Hickman and others. Embryo drawing from The Developing Human, Moore and Persaud, 5th ed., p. 73.)


The second meaning of the word alaqah is “suspended thing.” This is what we can see in figures 2 and 3, the suspension of the embryo, during the alaqah stage, in the womb of the mother.


Figure 2: We can see in this diagram the suspension of an embryo during the alaqah stage in the womb (uterus) of the mother. (The Developing Human, Moore and Persaud, 5th ed., p. 66.) (Click on the image to enlarge it.)



Figure 3: In this photomicrograph, we can see the suspension of an embryo (marked B) during the alaqah stage (about 15 days old) in the womb of the mother. The actual size of the embryo is about 0.6 mm. (The Developing Human, Moore, 3rd ed., p. 66, from Histology, Leeson and Leeson.)


The third meaning of the word alaqah is “blood clot.” We find that the external appearance of the embryo and its sacs during the alaqah stage is similar to that of a blood clot. This is due to the presence of relatively large amounts of blood present in the embryo during this stage4 (see figure 4). Also during this stage, the blood in the
embryo does not circulate until the end of the third week.5 Thus, the embryo at
this stage is like a clot of blood.

Figure 4: Diagram of the primitive cardiovascular system in an embryo during the alaqah stage. The external appearance of the embryo and its sacs is similar to that of a blood clot, due to the presence of relatively large amounts of blood present in the embryo. (The Developing Human, Moore, 5th ed., p. 65.) (Click on the image to
enlarge it.)


So the three meanings of the word alaqah correspond accurately to the descriptions of the embryo at the alaqah stage.

The next stage mentioned in the verse is the mudghah stage. The Arabic word mudghah means “chewed substance.” If one were to take a piece of gum and chew it in his or her mouth and then compare it with an embryo at the mudghah stage, we would conclude that the embryo at the mudghah stage acquires the appearance of a
chewed substance. This is because of the somites at the back of the embryo that
“somewhat resemble teethmarks in a chewed substance.”6 (see figures 5 and 6).

Figure 5:
Photograph of an embryo at the mudghah stage (28 days old). The embryo at this
stage acquires the appearance of a chewed substance, because the somites at the
back of the embryo somewhat resemble teeth marks in a chewed substance. The
actual size of the embryo is 4 mm. (The Developing Human, Moore and Persaud, 5th ed., p. 82, from Professor Hideo Nishimura, Kyoto University, Kyoto, Japan.)



Figure 6: When comparing the appearance of an embryo at the mudghah stage with a piece of gum that has been chewed, we find similarity between the two.
A) Drawing of an embryo at the mudghah stage. We can see here the somites at the back of the embryo that look like teeth marks. (The Developing Human, Moore and Persaud, 5th ed., p. 79.)
B) Photograph of a piece of gum that has been chewed.
(Click on the image to enlarge it.)

You can go click on the link above to read the entire article. There are other articles too, for instance the Quran on mountains, clouds, etc etc. Hope it benef'its you too, insya Allah! (: