Effect of paternal body mass index on maternal and child-health outcomes of singletons after frozen-thawed embryo transfer cycles: a retrospective study

Figures & data

Table 1. Parental and treatment characteristic of frozen embryo transfer (FET) cycles.

Characteristic (n = 1609)	Paternal underweight (n = 43)	Paternal normal weight (n = 835)	Paternal overweight (n = 607)	Paternal obesity (n = 124)	P^a	P^b	P^c
Maternal age (years)^e	32.63 ± 3.46	31.72 ± 3.92	31.50 ± 4.09	31.63 ± 3.77	0.295	0.145	0.802
Maternal BMI (kg/m^2)^e	21.92 ± 3.26	21.77 ± 3.43	21.37 ± 3.25	21.05 ± 2.88	0.154	0.768	0.077
Paternal age (years)^e	32.70 ± 4.08	32.89 ± 5.29	34.30 ± 4.29	33.09 ± 3.88	0.169	0.049	0.523
Paternal BMI (kg/m^2)^e	18.33 ± 1.83	22.37 ± 1.78	27.14 ± 1.65	32.29 ± 2.27	<0.001	<0.001	<0.001
Infertility duration (years)^d	2.0 (3.0–5.0)	2.0 (3.0–4.0)	3.0 (2.0–4.0)	2.0 (3.0–5.0)	0.245	0.476	0.293
Infertility cause
Female	67.44%	69.82%	66.06%	65.32%	0.853	0.741	0.801
	(29/43)	(583/835)	(401/607)	(81/124)
Male	11.63%	12.46%	12.69%	10.48%	0.840	0.873	0.835
	(5/43)	(104/835)	(77/607)	(13/124)
Mixed	20.93%	17.82%	21.25%	24.19%	0.960	0.539	0.663
	(9/43)	(148/835)	(129/607)	(30/124)
Gravidity
1	41.86	51.86%	51.24%	48.39%	0.235	0.201	0.460
	(18/43)	(433/835)	(311/607)	(60/124)
≥2	58.14%	48.14%	48.76%	51.61%
	(25/43)	(402/835)	(296/607)	(64/124)
Parity
0	81.40%	82.75%	84.18%	80.65%	0.630	0.818	0.914
	(35/43)	(691/835)	(511/607)	(100/124)
1	16.28%	15.93%	14.50%	18.55%
	(7/43)	(133/835)	(88/607)	(23/124)
≥2	2.36%	1.32%	1.32%	0.81%
	(1/43)	(11/835)	(8/607)	(1/124)
Number of abortions
0	46.51%	55.09%	55.85%	50.00%	0.234	0.270	0.693
	(20/43)	(460/835)	(339/607)	(62/124)
1	37.21%	25.27%	26.19%	29.84%
	(16/43)	(211/835)	(159/607)	(37/124)
≥2	16.30%	19.64%	17.96%	20.16%
	(7/43)	(164/835)	(109/607)	(25/124)
FET endometrial preparation
NC	20.93%	13.29%	14.99%	16.94%	0.297	0.155	0.557
	(9/43)	(111/835)	(11/607)	(21/124)
OI	6.98%	6.71%	8.07%	5.65%	0.798	0.945	0.751
	(3/43)	(56/835)	(49/607)	(7/124)
AC	72.09%	80%	76.94%	77.42%	0.468	0.209	0.481
	(31/43)	(668/835)	(467/607)	(96/124)
Stage of embryo transferred
Cleavage-stage embryo	25.58%	19.04%	19.93%	24.19%	0.672	0.290	0.178
	(11/43)	(159/835)	(121/607)	(30/124)
Blastocyst	74.42%	80.96%	80.07%	75.81%
	(32/43)	(676/835)	(486/607)	(94/124)
No. of embryos transferred
1	20.93%	18.92%	19.44%	19.35	0.805	0.744	0.909
	(9/43)	(158/835)	(118/607)	(24/124)
2	79.07%	81.08%	80.56%	80.65%
	(34/43)	(677/835)	(489/607)	(100/124)
Embryo quality
Good-quality	49.35%	47.02%	50.91%	47.32	0.058	0.690	0.934
	(38/77)	(711/1512)	(558/1096)	(106/224)
Poor-quality	50.64%	52.97%	49.09%	52.68%
	(39/77)	(801/1512)	(538/1096)	(118/224)

Abbreviations: AC, artificial cycle; BMI, body mass index; NC, natural cycles; OI, ovulation induction.

Data are presented as mean standard deviation for continuous variables and n (%) for dichotomous variables.

^aPaternal overweight vs. normal weight.

^bPaternal underweight vs. normal weight.

^cPaternal obesity vs. normal weight.

^dData are expressed as median (interquartile range) for non-normally distributed continuous variables.

^eData are expressed as mean + SD for normally distributed continuous variables.

Table 2. Pregnancy, perinatal complications according to paternal BMI.

Items	Paternal underweight (n = 43)	Paternal normal weight (n = 835)	Paternal overweight (n = 607)	Paternal obesity (n = 124)	P^a	P^b	P^c
Pregnancy complications
GDM	32.56%	34.13%	31.96%	29.83%	0.387	0.832	0.345
	(14/43)	(285/835)	(194/607)	(37/124)
Gestational hypertension	6.98%	3.59%	2.47%	2.42%	0.227	0.255	<0.001
	(3/43)	(30/835)	(15/607)	(3/124)
Preeclampsia	11.63%	4.43%	7.57%	4.03%	0.011	0.031	0.840
	(5/43)	(37/835)	(46/607)	(5/124)
Mild preeclampsia	4.65%	2.99%	4.61%	0.81%	0.107	0.539	0.162
	(2/43)	(25/835)	(28/607)	(1/124)
Severe preeclampsia	6.98%	1.44%	2.97	3.23%	0.151	0.006	0.290
	(3/43)	(12/835)	(18/607)	(4/124)
ICP	0%	0.60%	1.48%	0.81%	0.421	0.611	0.555
	(0/43)	(5/835)	(9/607)	(1/124)
Perinatal complications
Placenta previa	6.98%	2.75%	3.95%	4.03%	0.377	0.111	0.436
	(3/43)	(23/835)	(24/607)	(5/124)
Placental abruption	0	0.24%	0.36%	0	0.654	0.748	0.585
		(2/835)	(3/835)
PROM	16.28%	24.31%	20.43%	22.58%	0.082	0.229	0.674
	(7/43)	(203/835)	(124/607)	(28/124)
Abnormal placental cord insertion	4.65%	7.19%	2.64%	4.03%	0.307	0.718	0.808
	(2/43)	(30/835)	(16/607)	(5/124)
Placental adherence	13.95%	12.10%	13.51%	12.90%	0.426	0.716	0.798
	(6/43)	(101/835)	(82/607)	(16/124)
Placenta increta	2.33%	2.28%	1.81%	3.23%	0.543	0.983	0.519
	(1/43)	(19/835)	(11/607)	(4/124)
Postpartum haemorrhage	23.26%	17.13%	15.49%	14.52%	0.407	0.301	0.468
	(10/43)	(143/835)	(94/607)	(18/124)
Polyhydramnios	2.33%	2.99%	3.13%	2.42%	0.882	0.801	0.723
	(1/43)	(25/835)	(19/607)	(3/124)
Oligohydramnios	11.63%	3.11%	4.45%	4.03%	0.184	0.003	0.589
	(5/43)	(26/835)	(27/607)	(5/124)

Abbreviations: ART, Assisted reproductive technology; CI, Confidence interval; GDM, Gestational diabetes mellitus; ICP, Intrahepatic cholestasis of pregnancy; OR, Odds ratio; PROM, premature rupture of membranes; SC, spontaneous conception.

Data are expressed as No. (%).

P^a Paternal overweight vs. normal weight.

P^b Paternal underweight vs. normal weight.

P^c Paternal obesity vs. normal weight.

Table 3. Neonatal outcomes according to paternal BMI.

Items	Paternal underweight (n = 43)	Paternal normal weight (n = 835)	Paternal overweight (n = 607)	Paternal obesity (n = 124)	P^a	P^b	P^c
Newborn sex
Female (n = 732)	48.84% (21/43)	46.66% (389/835)	43.66% (265/607)	45.96% (57/124)	0.508	0.773	0.745
Male (n = 877)	51.16% (22/43)	53.41% (446/835)	56.34% (342/607)	54.03% (67/124)
Gestational age
<32 W (n = 24)	0	1.32% (11/835)	1.48% (9/607)	3.23% (4/124)	0.741	0.861	0.935
32–36 W (n = 147)	11.63% (5/43)	9.46% (79/835)	8.57% (52/607)	8.87% (11/124)
≥37 W (n = 1438)	88.37% (38/43)	89.22% (745/835)	89.95% (546/607)	87.90% (109/124)
LBW (<2500 g n = 92)	9.30% (4/43)	5.75% (48/835)	4.61% (28/607)	9.68% (12/124)	0.170	0.336	0.943
Macrosomia (≥4000 g n = 161)	2.33% (1/43)	8.38% (70/835)	12.36% (75/607)	12.10% (15/124)	0.013	0.155	0.175
1 min Apgar ≤7	2.33% (1/43)	0.59% (5/835)	0.82% (5/607)	0	0.320	0.180	0.089
5 min Apgar ≤7	2.33% (1/43)	0	0.66% (4/607)	0	0.227	<0.001	0.089
LGA (n = 486)	23.26% (10/43)	28.02% (234/835)	32.62% (198/607)	35.48% (44/124)	0.060	0.496	0.088
SGA (n = 46)	0% (0/43)	3.47% (29/835)	1.98% (12/607)	4.03% (5/124)	0.091	0.214	0.753

Abbreviations: LBW, low birth weight; LGA, large for gestational age; PTB, preterm birth; SGA, small for gestational age.

P^a Paternal overweight vs. normal weight.

P^b Paternal underweight vs. normal weight.

P^c Paternal obesity vs. normal weight.

Table 4. Pregnancy, perinatal complications and neonatal outcomes according to paternal BMI with stratified analysis by paternal age.

Items	Paternal underweight (n = 2)	Paternal normal weight (n = 34)	Paternal overweight (n = 27)	Paternal obesity (n = 5)	P^a	P^b	P^c
≥40 year
Pregnancy complications
GDM	0% (0/2)	64.70% (22/34)	55.55% (15/27)	20% (1/5)	0.467	0.068	0.058
Gestational hypertension	0% (0/2)	5.88% (2/34)	0% (0/27)	0% (0/5)	0.200	0.724	0.578
Preeclampsia	50% (1/2)	5.88% (2/34)	7.41% (2/27)	0% (0/5)	0.811	0.095	0.578
Mild preeclampsia	50% (1/2)	0% (0/34)	7.41% (2/27)	0% (0/5)	0.107	0.001	–
Severe preeclampsia	0% (0/2)	5.88% (2/34)	0% (0/27)	0% (0/5)	0.732	0.213	0.589
ICP	0% (0/2)	0% (0/34)	0% (0/27)	0% (0/5)	–	–	–
Perinatal complications
Placenta previa	0% (0/2)	2.94% (1/34)	11.11% (3/27)	0% (0/5)	0.200	0.806	0.698
Placental abruption	0% (0/2)	2.94% (1/34)	0% (0/27)	0% (0/5)	0.369	0.806	0.806
PROM	0% (0/2)	5.88% (2/34)	14.81% (4/27)	20% (1/5)	0.245	0.742	0.269
Abnormal placental cord insertion	0% (0/2)	5.88% (2/34)	7.41% (2/27)	0% (0/5)	0.811	0.724	0.724
Placental adherence	0% (0/2)	20.58% (7/34)	18.51% (5/27)	20% (1/5)	0.840	0.475	0.976
Placenta increta	0% (0/2)	2.94% (1/34)	7.41% (2/27)	20% (1/5)	0.423	0.806	0.106
Postpartum haemorrhage	50% (1/2)	20.58% (7/34)	29.63% (8/27)	40% (2/5)	0.415	0.331	0.336
Polyhydramnios	0% (0/2)	8.82% (3/34)	3.70% (1/27)	0% (0/5)	0.397	0.661	0.489
Oligohydramnios	0% (0/2)	0% (0/34)	0% (0/27)	20% (1/5)	–	–	0.008
Neonatal outcomes
Newborn sex
Female (n = 26)	50% (1/2)	47.06% (16/34)	18.52% (5/27)	80% (4/5)	0.020	0.935	0.169
Male (n = 42) (n = 42)	50% (1/2)	52.94% (18/34)	81.48% (22/27)	20% (1/5)
Gestational age
<32 W (n = 11)	0%	8.82% (3/34)	25.93% (7/27)	20% (1/5)
32–36 W (n = 16)	0%	11.76% (4/34)	37.04% (10/27)	40% (2/5)	0.004	0.475	0.087
≥37 W (n = 41)	100% (2/2)	79.41% (27/34)	37.04% (10/27)	40% (2/5)
Low birthweight (<2500 g) (n = 92)	0%	2.94% (1/34)	3.70% (1/27)	0%	0.868	0.806	0.698
Macrosomia (≥4000 g) (n = 161)	0%	5.88% (2/34)	7.41% (2/27)	20% (1/5)
1 min Apgar ≤ 7	–	–	–	–	–	–	–
5 min Apgar ≤ 7	–	–	–	–	–	–	–
LGA (n = 27)	50% (1/2)	23.53% (8/34)	41.18% (14/34)	80% (4/5)	0.120	0.401	0.011
SGA (n = 2)	0%	5.88% (2/34)	0%	0%	0.200	0.724	0.578

Abbreviations: ART, Assisted reproductive technology; CI, Confidence interval; GDM, Gestational diabetes mellitus; ICP, Intrahepatic cholestasis of pregnancy; OR, Odds ratio; LBW, low birth weight; LGA, large for gestational age; PROM, premature rupture of membranes; PTB, preterm birth; SC, spontaneous conception; SGA, small for gestational age.

Data are expressed as No. (%).

P^a Paternal overweight vs. normal weight.

P^b Paternal underweight vs. normal weight.

P^c Paternal obesity vs. normal weight.

Table 5. Pregnancy, perinatal complications and neonatal outcomes according to paternal BMI with stratified analysis by paternal age.

Items	Paternal underweight (n = 2)	Paternal normal weight (n = 34)	Paternal overweight (n = 27)	Paternal obesity (n = 5)	P^a	P^b	P^c
<40 years
Pregnancy complications
GDM	34.15% (14/41)	32.83% (263/801)	30.86% (179/580)	30.25% (36/119)	0.438	0.862	0.315
Gestational hypertension	7.32% (3/41)	3.49% (28/801)	2.59% (15/580)	2.52% (3/119)	0.337	0.205	0.582
Preeclampsia	9.76% (4/41)	4.37% (35/801)	7.59% (44/580)	4.20 (5/119)	0.011	0.109	0.933
Mild preeclampsia	2.44% (1/41)	3.12% (25/801)	4.48% (26/580)	0.84% (1/119)	0.185	0.805	0.161
Severe preeclampsia	7.32% (3/41)	1.25% (10/801)	3.10% (18/580)	3.36% (4/119)	0.016	0.002	0.079
ICP	0% (0/41)	0.62% (5/801)	1.55% (9/580)	0.84% (1/119)	0.089	0.612	0.785
Perinatal complications
Placenta previa	7.31% (3/41)	2.75% (22/801)	3.62% (21/580)	4.20% (5/119)	0.356	0.093	0.380
Placental abruption	0% (0/41)	0.12% (1/801)	0.52% (3/580)	0% (0/119)	0.180	0.821	0.700
PROM	17.07% (7/41)	25.09% (201/801)	20.69% (120/580)	22.69% (27/119)	0.056	0.245	0.571
Abnormal placental cord insertion	4.88% (2/41)	3.49% (28/801)	2.41% (14/580)	4.20% (5/119)	0.248	0.641	0.699
Placental adherence	14.63% (6/41)	11.74% (94/801)	13.28% (77/580)	12.61% (15/119)	0.391	0.576	0.784
Placenta increta	2.44% (1/41)	2.25% (8/801)	1.55% (9/580)	2.52% (3/119)	0.357	0.936	0.852
Postpartum haemorrhage	21.95% (9/41)	16.98% (136/801)	14.83% (86/580)	13.45% (16/119)	0.283	0.411	0.333
Polyhydramnios	2.44% (1/41)	2.75% (22/801)	3.10% (18/580)	2.52% (3/119)	0.696	0.906	0.888
Oligohydramnios	12.19% (5/41)	3.25% (26/801)	4.66% (27/580)	3.36% (4/119)	0.178	0.003	0.947
Neonatal outcomes
Newborn sex
Female (n = 706) (n = 706)	48.78% (20/41)	46.57% (373/801)	44.83% (260/580)	44.54% (53/119)	0.522	0.782	0.679
Male (n = 835) (n = 835)	51.22% (21/41)	53.43% (428/801)	55.17% (320/580)	55.46% (66/119)
Gestational age
<32 W (n = 13)	0%	0.99% (8/801)	0.34% (2/580)	2.52% (3/119)
32–36 W (n = 131)	12.19% (5/41)	9.36% (75/801)	7.24% (42/580)	7.56% (9/119)	0.078	0.708	0.926
≥37 W (n = 1397)	87.80% (36/41)	89.63% (718/801)	92.41% (536/580)	86.29% (107/119)
Low birthweight (<2500 g) (n = 90)	9.75% (4/41)	5.86% (47/801)	4.66% (27/580)	10.08% (12/119)	0.323	0.309	0.080
Macrosomia (≥4000 g) (n = 156)	2.44% (1/41)	8.49% (68/801)	12.59% (73/580)	11.76% (14/119)	0.013	0.168	0.242
1 min Apgar ≤ 7	2.44% (1/41)	0.62% (5/801)	0.86% (5/580)	0%	0.411	0.178	0.791
5 min Apgar ≤ 7	2.44% (1/41)	0%	0.68% (4/580)	0%	0.019	<0.001	–
LGA (n = 459)	21.95% (9/41)	28.21% (226/801)	31.72% (184/580)	33.61% (40/119)	0.159	0.383	0.225
SGA (n = 44)	0%	3.37% (27/801)	2.07% (12/580)	4.20% (5/119)	0.149	0.232	0.644

Abbreviations: ART, Assisted reproductive technology; CI, Confidence interval; GDM, Gestational diabetes mellitus; ICP, Intrahepatic cholestasis of pregnancy; OR, Odds ratio; LBW, low birth weight; LGA, large for gestational age; PROM, premature rupture of membranes; PTB, preterm birth; SC, spontaneous conception; SGA, small for gestational age.

Data are expressed as No. (%).

P^a Paternal overweight vs. normal weight.

P^b Paternal underweight vs. normal weight.

P^c Paternal obesity vs. normal weight.

Table 6. Associations between parental pre-pregnancy BMI and maternal outcomes of singletons in multilevel logistic regression analyses.

Items	Paternal underweight^a(n = 43)	P	Paternal overweight^a (n = 607)	P	Paternal obesity^a (n = 124)	P
GDM
Crude OR (95% CI)	0.932 (0.485–1.791)	0.832	0.907 (0.726–1.133)	0.388	0.821 (0.544–1.237)	0.345
AOR (95% CI)	0.894 (0.442–1.808)	0.754	0.888 (0.616–1.281)	0.525	0.748 (0.378–1.479)	0.404
Gestational hypertension	6.97%		2.47%		2.42%
Crude OR (95% CI)	2.012 (0.589–6.875)	0.265	0.680 (0.363–1.275)	0.229	0.665 (0.200–2.213)	0.506
AOR(95% CI)	1.962 (0.573–6.722)	0.283	0.667 (0.355–1.252)	0.207	0.654 (0.196–2.184)	0.490
Preeclampsia
Crude OR (95% CI)	2.838 (1.056–7.629)	0.039	1.768 (1.132–2.763)	0.012	0.906 (0.349–2.351)	0.840
AOR(95% CI)	2.970 (1.099–8.029)	0.032	1.830 (1.165–2.874)	0.009	0.978 (0.375–2.549)	0.963
ICP
Crude OR (95% CI)	–	–	2.498 (0.833–7.492)	0.102	1.350 (0.156–11.648)	0.785
AOR(95% CI)	–	–	2.393 (0.795–7.202)	0.121	1.343 (0.155–11.650)	0.789
Placenta previa
Crude OR (95% CI)	2.648 (0.763–9.189)	0.125	1.453 (0.812–2.600)	0.208	1.483 (0.553–3.976)	0.433
AOR(95% CI)	2.635 (0.754–9.211)	0.129	1.510 (0.836–2.726)	0.172	1.576 (0.582–4.265)	0.371
Placental abruption
Crude OR (95% CI)	–	–	2.069 (0.345–12.418)	0.427	–	–
AOR(95% CI)	–	–	3.863 (0.399–37.413)	0.243	–	–
PROM
Crude OR (95% CI)	0.605 (0.265–1.381)	0.233	0.799 (0.621–1.029)	0.082	0.908 (0.579–1.424)	0.674
AOR(95% CI)	0.629 (0.275–1.440)	0.273	0.786 (0.608–1.014)	0.064	0.945 (0.600–1.489)	0.807
Abnormal placental cord insertion
Crude OR (95% CI)	1.309 (0.302–5.666)	0.719	0.726 (0.392–1.345)	0.309	1.127 (0.429–2.963)	0.808
AOR(95% CI)	1.240 (0.284–5.406)	0.775	0.696 (0.375–1.291)	0.250	1.139 (0.431–3.006)	0.793
Placental adherence
Crude OR (95% CI)	1.178 (0.485–2.862)	0.717	1.135 (0.831–1.551)	0.426	1.077 (0.612–1.894)	0.798
AOR(95% CI)	1.169 (0.475–2.874)	0.734	1.215 (0.882–1.678)	0.234	1.104 (0.620–1.968)	0.735
Placenta increta
Crude OR (95% CI)	1.023 (0.134–7.822)	0.983	0.293 (0.374–1.678)	0.544	1.432 (0.479–4.280)	0.521
AOR(95% CI)	1.059 (0.137–8.186)	0.957	0.812 (0.379–1.741)	0.592	1.400 (0.459–4.272)	0.554
Postpartum haemorrhage
Crude OR (95% CI)	1.466 (0.707–3.043)	0.304	0.887 (0.667–1.178)	0.407	0.822 (0.483–1.398)	0.469
AOR(95% CI)	1.493 (0.716–3.113)	0.285	0.912 (0.684–1.216)	0.531	0.780 (0.451–1.348)	0.373
Polyhydramnios
Crude OR (95% CI)	0.771 (0.102–5.831)	0.801	1.047 (0.571–1.919)	0.882	0.803 (0.239–2.701)	0.723
AOR(95% CI)	0.731 (0.096–5.554)	0.762	1.029 (0.559–1.893)	0.928	0.751 (0.221–2.546)	0.645
Oligohydramnios
Crude OR (95% CI)	4.094 (1.490–11.251)	0.006	1.448 (0.837–2.508)	0.186	1.307 (0.496–3.470)	0.591
AOR(95% CI)	4.432 (1.594–12.328)	0.004	1.396 (0.804–2.423)	0.236	1.311 (0.492–3.494)	0.588

Abbreviations: CI, Confidence interval; GDM, Gestational diabetes mellitus; ICP, Intrahepatic cholestasis of pregnancy; OR, Odds ratio; PROM, premature rupture of membranes.

^aPaternal normal weight (n = 835) was used as the reference.

Table 7. Associations between parental pre-pregnancy BMI and neonatal outcomes of singletons in multilevel logistic regression analyses.

Items	Paternal underweight^a (n = 43)	P	Paternal overweight^a (n = 607)	P	Paternal obesity^a (n = 124)	P
PTB
Crude OR (95% CI)	1.131 (0.434–2.950)	0.801	0.926 (0.653–1.312)	0.644	1.094 (0.601–1.992)	0.768
AOR(95% CI)	1.165 (0.445–3.046)	0.756	0.926 (0.491–1.279)	0.669	1.119 (0.612–1.316)	0.715
LBW
Crude OR (95% CI)	1.682 (0.577–4.900)	0.341	0.793 (0.491–1.273)	0.342	1.757 (0.905–3.408)	0.096
AOR(95% CI)	1.674 (0.573–4.891)	0.347	0.788 (0.488–1.273)	0.330	1.822 (0.935–3.550)	0.078
Macrosomia
Crude OR (95% CI)	0.260 (0.035–1.919)	0.187	1.541 (1.092–2.173)	0.014	1.504 (0.831–2.720)	0.177
AOR(95% CI)	0.272 (0.037–2.007)	0.202	1.527 (1.078–2.163)	0.017	1.514 (0.832–2.753)	0.174
LGA
Crude OR (95% CI)	0.778 (0.378–1.604)	0.497	1.243 (0.991–1.560)	0.060	1.413 (0.949–2.102)	0.089
AOR(95% CI)	0.779 (0.377–1.611)	0.501	1.260 (1.001–1.587)	0.049	1.458 (0.974–2.183)	0.067
SGA
Crude OR (95% CI)	–	–	0.561 (0.284–1.108)	0.096	1.168 (0.443–3.076)	0.754
AOR(95% CI)	–	–	0.557 (0.281–1.103)	0.093	1.214 (0.459–3.212)	0.696

Abbreviations: PTB, preterm birth; LBW, low birth weight; LGA, large for gestational age; SGA, small for gestational age.

^aPaternal normal weight (n = 835) was used as the reference.