Table 2.

The effects of gestational weight gain in the first trimester (GWG-F) and rate of gestational weight gain in the second trimester (RGWG-S) on gestational diabetes mellitus (GDM), stratified by pre-pregnancy BMI, in the study sample of pregnant women (n 1910) from Southwest China, 2017

	GDM
	n	%	Adjusted OR	95 % CI	P
GWG-F*
Underweight
Within	22	16·9	1·000	Ref.	–
Below	21	15·7	1·011	0·488, 2·095	0·977
Above	17	23·6	2·500	1·106, 5·655	<0·05
Normal
Within	122	34·2	1·000	Ref.	–
Below	198	30·4	0·853	0·646, 1·126	0·262
Above	141	41·7	1·396	1·023, 1·906	<0·05
Overweight/obese
Within	21	38·2	1·000	Ref.	–
Below	43	43·0	2·060	0·818, 5·188	0·125
Above	35	49·3	3·017	1·118, 8·138	<0·05
RGWG-S†
Underweight
Within	16	16·2	1·000	Ref.	–
Below	24	24·7	1·724	0·817, 3·637	0·153
Above	17	12·9	0·841	0·386, 1·835	0·664
Normal
Within	184	37·2	1·000	Ref.	–
Below	121	41·3	1·109	0·790, 1·557	0·552
Above	144	27·2	0·744	0·550, 1·006	0·055
Overweight/obese
Within	23	46·0	1·000	Ref.	–
Below	25	54·3	1·219	0·501, 2·965	0·662
Above	49	39·2	0·757	0·365, 1·569	0·453

Ref., reference category.

^*Adjusted for maternal age, educational level, parity, employment, family history of diabetes, family history of hypertension, family history of thyroid diseases, average personal income per month, regular exercise before pregnancy, frequent exposure to a second-hand smoking environment before 6 months of pregnancy, and drinking before 6 months of pregnancy.

^†Adjusted for GWG-F based on the previous model.