I am working with the research conclusions made in this study that human fetal growth is mainly limited by the metabolism of the mother. And assuming a device that could produce sufficient cooling, oxygen, nutrients, and some sort of neurological stimulation, that humans babies would grow at the same rate as an elephant. For my story purposes, children in an artificial womb actually receive a holographic engram from a "mentor". Essentially, a person that whoever set up the apparatus would like the child-to-be to emulate in ability and muscle memory skill.

If we look at normal baby growth, we see a some odd hiccups during development that don't make it a smooth curve. I am assuming those are the points where the logistics of one human being having to compete with her own offspring for metabolic activity starts to become an issue.

Elephants and Whales are massive compared to their offspring. And they happily have multi-year pregnancies that produce offspring that weigh tens or even hundreds of kilograms. I'm going to use the Elephant as my upward model of fetal growth. Assuming an Indian elephant, they gave an 18 month gestation period that produces a calf that has a mass of 77 kg on average. I am also assuming that even though growth is a power law, there is an exponential decay in growth as the existing tissues also start to demand sustenance to maintain life.

I start the model at 10 weeks of pregnancy, and assume is has the same mass of 35 g of a human embryo. It starts with a 30% per week growth rate, and I decay the rate of growth by 32.399999999999984 per week. And after 80 weeks of growth, I have a fetus with a mass of 78 kg. Run the process to 90 weeks, one could have a fetus of over 100kg.

I am assuming that the facilities to produce a fully-grown artificial life form are a recent invention (as of the events in Project Gilgamesh.) My main character was built with an earlier process that could only get her and her contemporaries to a mass equivilent of a child of 5 or so. We'll say 20kg. That would have taken about 52 weeks.

Natural Development Artificial Development
Week Mass (g) Rate Mass (g) Rate
10 35 -   35 0.3
11 45 0.285714286   46 0.29028
12 58 0.288888889   59 0.28087492799999997
13 73 0.25862069   75 0.2717745803328
14 93 0.273972603   96 0.2629690839300173
15 117 0.258064516   121 0.25444888561068474
16 146 0.247863248   152 0.24620474171689855
17 181 0.239726027   189 0.23822770808527102
18 223 0.232044199   234 0.23050913034330825
19 273 0.224215247   288 0.22304063452018508
20 331 0.212454212   352 0.21581411796173108
21 399 0.205438066   428 0.208821740539771
22 430 0.077694236   517 0.20205591614628243
23 501 0.165116279   622 0.19550930446314288
24 600 0.19760479   743 0.18917480299853706
25 660 0.1   884 0.18304553938138446
26 760 0.151515152   1046 0.1771148639054276
27 875 0.151315789   1231 0.17137634231489177
28 1005 0.148571429   1442 0.16582374882388928
29 1153 0.147263682   1681 0.16045105936199527
30 1319 0.143972246   1950 0.15525244503866664
31 1502 0.138741471   2253 0.15022226581941384
32 1702 0.133155792   2592 0.14535506440686483
33 1918 0.126909518   2968 0.1406455603200824
34 2146 0.118873827   3386 0.13608864416571173
35 2383 0.110438024   3846 0.13167937209474267
36 2622 0.100293747   4353 0.127412960438873
37 2859 0.090389016   4908 0.12328478052065353
38 3083 0.078349073   5513 0.11929035363178436
39 3288 0.066493675   6170 0.11542534617411455
40 3462 0.052919708   6882 0.11168556495807325
41 3787 0.093876372   7651 0.10806695265343168
42 - -   8478 0.1045655833874605
43 - -   9364 0.10117765848570678
44 - -   10312 0.09789950235076988
45 - -   11321 0.09472755847460494
46 - -   12394 0.09165838558002774
47 - -   13530 0.08868865388723485
48 - -   14730 0.08581514150128844
49 - -   15994 0.08303473091664669
50 - -   17322 0.08034440563494734
51 - -   18714 0.07774124689237505
52 - -   20169 0.0752224304930621
53 - -   21686 0.07278522374508689
54 - -   23264 0.07042698249574608
55 - -   24903 0.06814514826288391
56 - -   26600 0.06593724545916647
57 - -   28353 0.06380087870628948
58 - -   30162 0.0617337302362057
59 - -   32024 0.059733557376552636
60 - -   33937 0.05779819011755233
61 - -   35899 0.055925528757743634
62 - -   37907 0.05411354162599274
63 - -   39958 0.052360262877310576
64 - -   42050 0.05066379036008571
65 - -   44180 0.04902228355241894
66 - -   46346 0.047433961565320565
67 - -   48545 0.04589710121060418
68 - -   50773 0.04441003513138061
69 - -   53027 0.042971149993123875
70 - -   55306 0.041578884733346665
71 - -   57606 0.04023172886798623
72 - -   59923 0.03892822085266348
73 - -   62256 0.03766694649703718
74 - -   64601 0.03644653743053318
75 - -   66955 0.03526566961778391
76 - -   69317 0.034123061922167706
77 - -   71682 0.03301747471588947
78 - -   74049 0.031947708535094654
79 - -   76414 0.030912602778557587
80 - -   78777 0.029911034448532322
81 - -   81133 0.028941916932399874
82 - -   83481 0.028004198823790117
83 - -   85819 0.02709686278189932
84 - -   88144 0.026218924427765782
85 - -   90455 0.02536943127630617
86 - -   92750 0.02454746170295385
87 - -   95027 0.023752123943778146
88 - -   97284 0.022982555127999734
89 - -   99520 0.022237920341852544
90 - -   101733 0.021517411722776523