Table 4.

Adjusted odds ratios of LBW by multivariate analysis of predictor variables.

Predictor variable	aOR (95% CI)	P value
Maternal age	1.02 (0.978-1.064)	0.362
EMT
7.5<EMT ≤ 12	1
EMT ≤ 7.5	2.179 (1.305-3.640)	0.003*
EMT >12	0.584 (0.403-0.844)	0.004*
Maternal BMI	1.004 (0.971-1.039)	0.799
Infertility duration	0.969 (0.916-1.026)	0.284
Parity
0	1
≥1	0.776 (0.469-1.286)	0.325
FET cycle rank
0	1
≥1	0.866 (0.654-1.147)	0.315
Infertility type
Primary	1
Secondary	0.801 (0.617-1.038)	0.093
Infertility cause
Female factor	1
Male factor	1.189 (0.852-1.659)	0.309
Mixed	0.952 (0.667-1.358)	0.785
Unexplained	1.311 (0.809-2.123)	0.272
Fertilization type
IVF	1
ICSI	0.956 (0.708-1.29)	0.767
Endometrial preparation protocols
NC	1
HRT	1.152 (0.811-1.636)	0.431
GnRH agonist-HRT	1.084 (0.74-1.589)	0.678
No. of transferred embryos
1	1
2	1.149 (0.897-1.471)	0.271
Stage of embryo transferred
Cleavage stage	1
Blastocyst stage	1.254 (0.953-1.65)	0.106
No. of good-quality embryo transfer
0	1
≥1	1.087 (0.865-1.367)	0.475
Cesarean delivery
No	1
Yes	1.082 (0.824-1.421)	0.570
Newborn gender
Male	l
Female	1.474 (1.182-1.838)	0.001*
Pregnancy complications
No	1
Yes	7.075 (5.591-8.953)	<0.001*

Adjustment included maternal age, maternal BMI, infertility duration, parity, FET, cycle rank, infertility type, infertility cause, fertilization type, endometrial preparation protocols, number of transferred embryos, stage of embryo transferred, number of good-quality embryo transfer, cesarean delivery, newborn gender and pregnancy complications. aOR, adjust odds ratio; CI, confidence interval; BMI, body mass index; FET, frozen embryo transfer; EMT, endometrial thickness; IVF, in vitro fertilization; ICSI, intracytoplasmic sperm injection; NC, natural cycle; HRT, hormone replacement therapy; GnRH, gonadotropin-releasing hormone.

^*P < 0.05 was considered statistically significant.