Table 22. Fetal thyroid mass models (g vs. fetal mass in g for power law models, g vs. gestational age in weeks for all other models).

Model	${\widehat{\mathit{\theta }}}_0$	${\widehat{\mathit{\theta }}}_1$	${\widehat{\mathit{\theta }}}_2$	${\widehat{\mathit{\theta }}}_3$	$\mathcal{l}\left(\widehat{\mathit{\theta }}\right)$	AIC
Linear Growth	0.014960	—	—	—	28.2108	-54.42
Quadratic Growth	-0.015229	0.0014665	—	—	168.39	-332.78
Cubic Growth	-0.0029982	0.00043792	1.9641×10−5	—	170.08	-334.16
Gompertz	0.0038483	0.30799	0.039800	—	170.035	-334.07
Logistic	2.6022	0.14914	34.613	—	169.644	-333.29
Power Law	0.0050755	0.71057	—	—	164.447	-324.89
Luecke Power Law	0.10683	-0.25045	0.073247	—	169.579	-333.16

For each model considered, the maximum likelihood parameter estimates ($\widehat{\theta }$), log-likelihood ($\mathcal{l}\left(\widehat{\theta }\right)$), and AIC are provided. The row describing the selected model is shown in boldface.