Table 4. Distribution of BMI categories, gestational weight gain categories, and birthweight z-scores in the reference and the pregestational diabetes mellitus population (160 and 49 participants, respectively).

		Reference Median (range)			PGDM Median (range)
BMI (kg/m2)		23.0 (17.0–41.0)			25.4 (19.8–44.1)
GWG/week (kg/week)		0.37 (0.01–0.73)			0.46 (-0.14–0.95)
	Category	n	%	Mean BW z-score	n	%	Mean BW z-score
BMI	Underweight	7	4.4	-0.15	2	4.1	1.47
	Normal weight	101	63.1	-0.11	22	44.9	0.62
	Overweight	43	26.9	0.17	14	28.6	2.02
	Obese	9	5.6	-0.52	11	22.4	0.59
p *				0.224			0.001*
GWG	Insufficient	47	29.4	-0.16	6	12.2	0.31
	Appropriate	61	38.1	-0.08	16	32.7	0.60
	Excessive	47	29.4	0.10	27	55.1	1.48
p *				0.556			0.008*
Total group		160		-0.06 (-3.02–1.81)	49		1.05 (-2.15–5.82)

PGDM, pregestational diabetes; BMI, body mass index (kg/m²); BMI categories defined by Institute Of Medicine guidelines: BMI; underweight (<18.5), normal weight (18.5–24.9), overweight (25–29.9), obese (≥30); BW, birthweight; GWG, weekly gestational weight gain; GWG category defined by Institute Of Medicine: insufficient, appropriate, excessive; z-score, standard deviation score

* p<0.05, difference between BMI and GWG categories within the reference and the PGDM populations tested by ANOVA.