2
Quite true unfortunately. However Astrology I think doesn't work on the level of 'basic personality' traits but more like an influence upon the choices they will make 'freely'.

There aren't exactly a lot of choices in-utero I don't think. Although I don't really know. As far as I can tell, everyone in Utero would have the chart of their mother, because the key thing is breath.

3
Conception charts are not unknown in astrology. In some long forgotten text I recall reading where the astrologer would remain hidden in the bedchamber on the wedding night of a royal personage in order to determine the time of conception. How he did that I'll leave to the imagination.

In fact most techniques for determining conception charts require a birth chart. Holden suggests the origin of using birth charts to determine conception goes back to the early third century BC (A History of Horoscopic Astrology p 51). Valens' Anthology gives a method of determining conception in Book 1, Chapter 21. Then there is the ever popular "Trutine of Hermes" covered in the Centiloquoy falsely attributed to Ptolemy. Lilly mentions it. Porphry also discusses the subject.

One method is to take the sign and degree of the Moon in the nativity and that is the rising sign at conception. Since that sign and degree rises once per day, I'm not real sure how it pinpoints conception. Then there is the method that takes the Moon sign and degree at birth and at conception it would be either opposite that place or in the same place. Again even with a two-week leeway, this leaves a lot of room for error.

Then, of course there is the question: "Once we've determined the conception chart, what do we do with it?" It never caught on as an important technique. However, for a more modern treatment of this topic see The Prenatal Epoch by E.H. Bailey. Or use the prenatal eclipse.

Tom

4
Its true that personality traits start developing in the womb but on the other hand it is also true; till now; that the exact conception time cannot be known. As per medical science sperm may stay alive for 3 days and the ovum need to get fertilized in 24 hours (approx.). Now again, the question arises that Which time should be considered i.e. injection of sperms ( may be intercourse etc.) or meeting of sperm with ovum? Also the fuetus has no indpenedent indentity without mother's womb. So it is better to consider the Bith Chart because at bith time, the child shows his independent presence to the external world, also he comes under the direct influence of planets.

Finding the Conception moment

5
Since the time of Ptolemy, generations of astrologers have tried to discover a way to determine the date and time of conception. However al of the many attempts, including those made in this century by such as Bailey and Jayne, have been in vain. In 1980 Alexander Marr discovered a simple method for determining the Prenatal Epoch.
Rectifying the Ascendant to within 2-3 minutes of arc is a pre-condition for finding the Epoch.
It has been found that in most cases, analysis of the Epoch can cast a sharper perspective on the destiny of the native. It also enables us to perform the Dual-Test, so called because it analyzes directions of Radix to Epoch factors and vice versa. This quadruples the number of aspects, compared with the usual Radix analysis and thus improves the directional system considerably by providing a large number of appropriate aspects for any event. This fact enables us for the first time to make much more accurate predictions.
The following is a summary of the main principles for finding the exact conception moment or Prenatal Epoch, as formulated by Alexander Marr in 1980:
1. A birth time rectified to within 8 seconds of time is indispensable.
2. The Moon?s longitude at Epoch is the longitude of the Radix Ascendant or Descendant, to a maximum orb of 8? and an average orb of 2?. However, the ancient rule that the Ascendant or Descendant at Epoch should occupy the longitude of the radical Moon is incorrect. Horoscope with well authenticated birth time could not be forced to fit into the ancient mutually dependent conditions.
3. With a normal gestation period, the Epoch date must occur approximately 271 days before birth. For gestation periods known to be shorter than normal, seek an Epoch date accordingly, up to 7 or 8 months before birth.
4. In most cases, the Moon is either waxing in both Radix and Epoch,
or waning in both.
5. This is the starting point for refining the Epoch rectification with Primaries, as with the Radix.
The Epoch is not a way to rectify a birth chart. First one should rectify the Radix!
How I know that a certain Epoch is indeed the true one? By checking it with the same techniques I 'm using for the Radix, i.e. :
1. Primary Direction in Topocentric system
2. Secondary Directions using the Solar Arc in Right Ascension for house-directions
3. Secondary directions derived from the Sidereal Solar Returns- PSSR (Cyril Fagan?s system)
4. Lunar Cycles: lunar return, kinetic lunar and Asc-lunar, both direct and converse, precession-corrected.
5. Transits to Angles and cusps, both direct and converse.

Example: Frank Sinatra was born on 12 Dec 1915 03.00 am in Hoboken, NJ. My rectification is 07.58.49 UT Asc 28Lib 09'
The Epoch is rectified to 18 March 1915 13.55.47 UT, Moon 28Ari08'. In moth charts, The Moon is waxing.
In the Radix, Nep on MC and Sun & Mer 60 Jup.
In the Epoch, the triple conjunction of Ven, Ura and MC gave him his great signing and entertainment talent.
For a full details with many examples see Alexander Marr's books especially "Prediction III", now out of print.
After rectifying over 600 charts with the Pre natal Epoch I can determine without hesitation that in most cases, the Epoch reflects the destiny much more clearly.