Anyone have some medical advice on embryonic development?

The Buddhist texts contain a theory of prenatal development, one of the earliest if not the earliest found anywhere. The principle underlying this is that the embryo undergoes a gradual process of growth, little by little acquiring the physical features and sense organs. During this process the embryo is nurtured by the food supplied by the mother. In other words, it is a naturalistic explanation.

In SN 10.1 this process is given in response to a question by a yakkha, who believes in a soul theory, specifically that the soul is rūpa, i.e. that one’s essence is material.

While it might seem odd to have a yakkha so invested in matters of procreation, in fact one of their chief roles was in childbirth and fertility. Like many deities of the ancient world, yakkhas or yakkhinis could just as well be the agent of death (perhaps smallpox) that took children away, or the blessed spirit who delivered them. To make sure you get the right kind of yakkha involvement, you have to pay insurance, i.e. sacrifice. Such sacrifices, it seems, often required the death of children. Give up one child now, get a lot more later.

So if the Buddha attests that the growth and health of an embryo is purely a natural process, and the mother need only stay healthy and eat well, then this is a direct challenge to the livelihood of the yakkhas.

Anyway, the prenatal theory involves a series of four preliminary stages. These are usually left untranslated. However, given that Indian medical science is usually grounded in keen observation, I wonder whether they might correspond with actual developmental stages. Hence my question.

Here are the stages, with a brief explanation as best as I can. Remember that they had no advanced technology, so any changes must have been visible to the naked eye.

  1. kalala: Apparently = “mud”, also used for an oily residuum, and the yolk of an egg. Probably a predifferentiated state. (blastocyst?)
  2. abbuda: Apparently = “tumour”.
  3. pesi: a lump of flesh, a piece of meat.
  4. ghana: A mass; interpreted by the dictionary here as a “swelling”.

After this, the limbs, hair, and nails are said to emerge.

The much later Visuddhimagga adds a little detail to this, although as always it is uncertain whether this is the same as that found in the suttas.

The four stages are said to occur in the first month.

The kalala is said to be “no more than a drop of cream of ghee on a single fibre of new-born [kid’s] wool”.

Sorry, that’s not much to go on. Anyway, if there are any modern terms that approximate to these, I would be interested to learn.

While it may not be possible to identify these stages exactly, I think that leaving them untranslated—as most translators do—does a disservice to the text. Each of the terms clearly stands for something that can easily be understood as a naturalistic observation of prenatal development. If we don’t translate them, we leave open the implication that they refer to a supernatural process.



This topic always fascinated me and I think you are right, this is very much likely the most ancient theory of prenatal development.

A question I have is whether the stages were based in actual observation or it is a bonus outcome of the threefold superhuman knowledge/insights (tevijja).

As well, I would like to challenge if the prenatal development theory would endorse the view that contraceptive methods which frustrate fertilization - like taking the pill - would configure a breach of the first precept.

If I am not wrong, there is a risk that a woman on pills will discharge something close to the kalala “thing”, isn’t there?

This link should help:


Hormonal contraception is complex and works in a number of ways to prevent pregnancy such as thickening cervical mucus to prevent implantation, And completely stopping ovulation, so it’s not so clear cut. Women can often expel a fertilized egg and not realize regardless of contraceptive use.

The human ovum is visible to the naked eye. I would correlate that with ‘kalala’, (fertilized/zygote or not) up to 5-8 days post fertilization where the egg implants into the uterus attaching itself (here- blastocyst) and growing like a little lump from there, hence ‘Tumor’ =’ Abbuda’
After that point I’m not really sure… It goes from a lump to a mass? Maybe I can add more later…


Well, this is beside the topic, but in any case the theory says nothing about the ethical aspects, so no.

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Perhaps not totally relevant, but there’s a catchy phrase in biology that goes “Ontogeny Recapitulates Phylogeny”. Fancy words, which basically mean the development of the fetus roughly mirrors the animal’s evolution. (This ORP Theory has since been dismissed in modern biology, but there is some truth to it.)

The human fetus goes from a clump of cells (probably roughly resembling early multicellular life)… to having gill-like structures! (like fish)… to having a tail! (like monkeys aka lower primates)

The “gills” becom the ear structure and the tail recedes (though a remnant remains as the coccyx/“tail-bone” which is vestigial).

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Kalala might just refer to fertility, e.g. soil. The rest seem to be external descriptions. Stages referred to as a tumor, a lump, and a swelling are all ways a midwife might assess pregnancy by feeling a woman’s belly.
-SweaterFish from


That’s a very good point! This means that he may not be referring to the thing growing inside but actually to the stages of external marks of pregnancy ?

Seems unlikely: remember these all occur before the appearance of significant physical features in the embryo, and are said to be in the first month. But then, I’ve never been pregnant!

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I agree that ‘kalala’ may potentially mean just fertility, except that as Bhante described…[quote=“sujato, post:1, topic:3607”]
The kalala is said to be “no more than a drop of cream of ghee on a single fibre of new-born [kid’s] wool”.

That would be an extremely strange way to characterise ‘fertility’, unless it was referring to simply the presence of an ovum, which would fit above description.

It was also mentioned…[quote=“sujato, post:1, topic:3607”]
The four stages are said to occur in the first month.

You can’t tell a woman is pregnant externally in the first month. I would say the following stages ie, [quote=“sujato, post:1, topic:3607”]
pesi: a lump of flesh, a piece of meat.

ghana: A mass; interpreted by the dictionary here as a “swelling”.

probably just refer to the development of the blastocyst. After week 4 is when it actually starts to look like a ‘thing’ rather than a ‘blob’. Yes, I know. Very technical.

Wikipedia says -

In animals, the development of the zygote into an embryo proceeds through specific recognizable stages of blastula, gastrula, and organogenesis.

So within the first month there is egg->zygote (fertilisation), then cell division (morula), blastocyst formation, implantation, forming of the gastrula (gastrulation), then the beginning of organ formation and placental development.

I think the first two stage are clear from the translation -
1.Ovum or zygote (newly fertilised egg)
2. Implantation - blastocyst

As for 3 and 4, after this point the cells are starting to differentiate and specialise to be formed into organs. These stages are not really clear from the translations but…
The gastrula - a three layered structure - each of the three layers will eventually differentiate into different organ groups. The placenta also starts developing after implantation (maybe piece of meat? the cells at this stage do look like a chewed up piece of gristle…)
Then after the differentiation the heart starts beating, it’s starting to grow and become more like something that we would recognise visually as something, with distinguishing features, and finally called an embryo.

My knowledge about this is pretty limited…and I have also never been pregnant! So hopefully an embryologist will stumble across this thread and clear this up further for us :laughing: apologies if anything is wrong!


@Cara, yours sounds much more well-informed. Just thought that reddit user’s perspective was interesting as I hadn’t considered it in thinking about this.

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Here’s something helpful:

…but mapping Iron Age descriptions to this level of modern medicine is probably inappropriate…


1.Kalala: possibly the stage of embryo, where following fertilisation the cells divide (up to 16 cells).


2: Abbuda: I like the translation ‘swelling’.

The name “Blastocyst” arises from the Greek βλαστός blastos (“a sprout”) and κύστις kystis (“bladder, capsule”)

In humans, Blastocyst formation begins about 5 days after fertilization, when a fluid-filled cavity opens up in the morula, a ball consisting of a few dozen cells.

The Blastocyst has a diameter of about 0.1-0.2 mm and comprises 200-300 cells. After about 1 day (5–6 days post-fertilization), which is the time usually required to reach the uterus, the Blastocyst begins to embed itself into the endometrium of the uterine wall where it will undergo later developmental processes, including Gastrulation.


3.Pesi: a lump of flesh, a piece of meat.

Pesi might mean ‘muscle’ - ‘mansa-pesi’ means muscles in Sinhalese. Muscles (voluntary skeletal and involuntary gut and heart muscles) grow during gastrulation. This
takes place around the sixteenth day (week 3) after fertilisation.

'The single-layered Blastula is reorganized into a trilaminar (“three-layered”) structure known as the Gastrula. The three germ layers are the Ectoderm, Mesoderm and Endoderm.

The middle layer of Mesoderm will give rise to the heart and the beginning of the circulatory system as well as the bones, muscles and kidneys’.


4. Ghana:

Ghana probably means a mass. The Blastocyst was more a bubble but at this stage the three germ layers fold to form the gut tube and it looks more like a solid thing or animal. (See Ghana Sanna)


5. Pasākha:the body where it branches from the trunk.

‘In the fourth week limb development begins’.

After this, the limbs, hair, and nails are said to emerge.

‘From the 11th to the 16th week, the fetus develops hair, nails’.

The Buddhist descriptions seem to have two components : they are quite visual (drop of ghee, tumour, mass) but also draws out meaning that cannot be solely deduced from a visual image (muscle development, for example). These particular stages within the first four weeks of life cannot be felt externally (having examined pregnant women in my early medical training) as they are only a few cells/millimeters in size. Even if it was expelled from the body they probably didn’t have microscopes powerful enough to see individual cells 2600 years ago. However the use of the faculty of Dibba Chakku (Divine Eye) provides a textually valid explanation.

Incidentally my medical and Buddhist training helped me with writing this.

Here’s a good slideshow on the entire process:

With metta



Perhaps they could see a clump of cells under the right conditions even with just the naked eye. Check out this really cool visual aid to the microscopic world.

A quote from that page:

The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny.

The human egg cell shown there is 130 um which is equal to 0.130 mm.

Also, though we can be quite certain they didn’t have microscopes, it’s possible they could have had primitive magnifying lenses.

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I think it is unlikely that the Buddha would go and find a group of women who had aborted their foetuses spontaneously and looked at their menstrual discharge for products of conception.

He would need quite a few women to find embryo of different ages. I think it would be an impossible thing to do, inviting criticism, putting at risk his entire dispensation.

I agree, that scenario is very unlikely. Knowledge gained via supernormal power is actually a more plausible scenario to me.

It is possible that medical specialists in ancient times could have roughly figured this out via visual observation. I wouldn’t put it past some curious and possibly ruthless king to order his “obstetricians” to discover how a human develops in the womb. After all, it’s obvious to even the most primitive person that the new human starts off small, grows larger, and eventually comes out. It’s just a matter of figuring out what to look for and where.


I think you might be right. Looks like these stages were described in the Vedas:

with metta



Just a note, the same stages are described in a Uighur text:


I would like to bring to this thread the question whether the use of anticoncepcional methods like the pill could be considered problematic vis-a-vis one’s adherence to percepts and cultivation of virtue.

In the Bhikkhu Vinaya bhikkhus are clearly prohibited from prescribing and helping lay disciples abort babies:

But I cannot recall to find any clear relationship between the stages of prenatal development listed in the sutta mentioned at the beginning of this topic (SN10.1) and the moral implications of interrupting it at its earliest stages of maturation.

Would it be right to say that the choice of vasectomy by the husband would be more of a safe bet in terms of keeping of the percepts by a couple than the wife taking of pills?

P.S.: it’s noteworthy that Bhante Sujato has once answered a similar question saying basically that it is not a very clear cut issue and definitely there is an issue of temporarility and graduality in the process of establishing of a new being into the womb of a woman.