Analysis of influencing factors of postpartum depression in patients with gestational diabetes mellitus and construction of prediction model

Table 1 Comparison of data between postpartum depression group and no-postpartum depression group, mean ± SD/n (%)

Project	PPD group (n = 52)	No-PPD group (n = 152)	t/χ2 value	P value
Age (years)	29.25 ± 4.23	28.75 ± 4.18	0.742	0.459
Educational level			2.346	0.126
High school and below	30 (57.69)	69 (45.39)
College degree or above	22 (42.31)	83 (54.61)
Place of residence			0.641	0.726
Countryside	14 (26.92)	34 (22.37)
Township	18 (34.62)	51 (33.55)
City	20 (38.46)	67 (44.08)
Birth history			0.292	0.589
Primipara	19 (36.54)	62 (40.79)
Multipara	33 (63.46)	90 (59.21)
Pre-pregnancy body mass index (kg/m2)	23.27 ± 2.73	22.95 ± 2.89	0.699	0.485
FPG (mmol/L)	5.84 ± 1.28	5.62 ± 1.13	1.171	0.243
1hPG (mmol/L)	9.89 ± 2.27	9.55 ± 2.27	0.910	0.364
2hPG (mmol/L)	8.68 ± 0.54	8.49 ± 0.48	2.385	0.018
FINS (mmol/L)	15.07 ± 2.31	14.68 ± 2.25	1.072	0.285
Blood glucose control methods			1.287	0.257
Subcutaneous injection of insulin	13 (25.00)	27 (17.76)
Diet and exercise therapy	39 (75.00)	125 (82.24)
Blood glucose control during pregnancy			6.285	0.012
Good	20 (38.46)	89 (58.55)
Poor	32 (61.54)	63 (41.45)
Type of delivery			1.853	0.173
Caesarean section	24 (46.15)	54 (35.53)
Vaginal delivery	28 (53.85)	98 (64.47)
Neonatal sex			0.224	0.636
Baby boy	29 (55.77)	79 (51.97)
Baby girl	23 (44.23)	73 (48.03)
Postpartum mother infant separation			11.386	0.001
Yes	14 (26.92)	13 (8.55)
No	38 (73.08)	139 (91.45)
Feeding methods for newborns			1.440	0.487
Artificial feeding	8 (15.38)	17 (11.18)
Mixed feeding	19 (36.54)	48 (31.58)
Exclusive breast feeding	25 (48.08)	87 (57.24)
Family care level			13.539	0.001
High	7 (13.46)	49 (32.24)
Medium	21 (40.39)	70 (46.05)
Low	24 (46.15)	33 (21.71)
Social support			10.057	0.007
High	9 (17.31)	53 (34.87)
Medium	22 (42.31)	68 (44.74)
Low	21 (40.38)	31 (20.39)

FPG: Fasting plasma glucose; 1hPG: 1-hour postprandial oral glucose tolerance test glucose; 2hPG: 2-hour postprandial oral glucose tolerance test glucose; FINS: Fasting insulin; PPD: Postpartum depression.

Table 2 Each variable assignment description

Variable	Description of valuation
2hPG	Enter the actual value
Blood glucose control during pregnancy	0 = good; 1 = poor
Postpartum mother infant separation	0 = no; 1 = yes
Family care level	0 = high; 1 = medium; 2 = low
Social support	0 = high; 1 = medium; 2 = low

2hPG: 2-hour postprandial oral glucose tolerance test glucose.

Table 3 Results of multivariate logistic analysis

Variable	β	SE	χ2	P value	OR (95%CI)
2hPG	0.508	0.251	4.096	0.043	1.662 (1.016-2.718)
Poor blood glucose control during pregnancy	0.687	0.288	5.690	0.017	1.987 (1.131-3.494)
Postpartum mother infant separation	1.092	0.302	13.075	< 0.001	2.980 (1.649-5.387)
Family care level
Medium	0.252	0.172	2.147	0.143	1.287 (0.919-1.802)
Low	0.745	0.293	6.465	0.011	2.106 (1.186-3.739)
Social support
Medium	0.289	0.168	2.959	0.085	1.335 (0.961-1.855)
Low	0.493	0.206	5.727	0.017	1.637 (1.093-2.452)
Constant term	-4.766	1.079	19.510	< 0.001

2hPG: 2-hour postprandial oral glucose tolerance test glucose; OR: Odds ratio; CI: Confidence interval.

Table 4 Cross validation depth evaluation results of prediction models

Indicator	Modeling data values	Correction value	Change value (Δ)
AUC/C-index	0.840	0.847	0.007
R2	0.638	0.646	0.008
Differentiation index (D)	0.505	0.487	-0.018
U inspection	-0.007	0.019	0.012
Brier score	0.088	0.124	0.036
Maximum offset Emax	0.073	0.235	0.162
Minimum offset Eavg	0.016	0.142	0.126

AUC: Area under the curve.