. 2016 Jun 18;33(9):1203–1213. doi: 10.1007/s10815-016-0757-6

Table 2.

Description of perinatal outcomes by fertility status groups

Perinatal outcomes	Birth order	Fertility status at first birth							p value
		Fertile			Subfertile		ART		Within groups
		F-F	F-S	F-A	S-S	S-A	A-S	A-A	Fertile	Subfertile	ART
N (pairs)		56,755	249	380	787	105	635	853
Preeclampsia (%)	First birth	1.2	0.8	0.5	1.5	4.8	1.4	1.6	0.44	0.02	0.73
Preeclampsia (%)	Second birth	0.7	0.8	1.1	1.9	1.0	0.5	1.3	0.64	0.49	0.11
Gestational diabetes (%)	First birth	4.1	2.8	3.7	8.1	3.8	6.5	6.5	0.53	0.12	0.99
Gestational diabetes (%)	Second birth	5.2	6.8	7.4	7.1	3.8	6.0	7.2	0.08	0.20	0.37
Abruptio placenta or placenta previa (%)	First birth	1.4	1.6	1.8	3.2	1.9	6.6	4.3	0.70	0.47	0.05
Abruptio placenta or placenta previa (%)	Second birth	1.6	1.6	4.7	1.7	4.8	2.4	5.0	<0.0001	0.03	0.008
Primary cesarean birth (%)	First birth	30.2	37.8	42.9	39.4	45.7	44.3	39.9	<0.0001	0.21	0.09
Primary cesarean birth (%)	Second birth^a	8.1	10.3	15.3	10.7	14.0	9.6	14.4	0.0003	0.45	0.03
Repeat cesarean birth (%)	Second birth^b	79.4	87.2	82.8	82.6	83.3	79.0	85.3	0.10	0.90	0.04
Infant gender (% male)	First birth	51.5	46.2	53.4	50.8	49.5	55.1	51.9	0.19	0.80	0.22
Infant gender (% male)	Second birth	51.3	45.4	49.2	51.2	49.5	52.3	51.6	0.13	0.75	0.79
Preterm birth (%)	First birth	6.4	10.0	6.3	7.5	8.6	9.8	10.0	0.07	0.70	0.90
Preterm birth (%)	Second birth	4.6	8.0	8.2	4.7	6.7	4.7	9.3	0.0002	0.38	0.0009
Low birthweight (%)	First birth	5.6	6.8	6.1	6.4	10.5	7.2	7.9	0.62	0.12	0.66
Low birthweight (%)	Second birth	3.3	5.6	6.1	3.1	7.6	1.4	6.7	0.002	0.02	<0.0001
Small-for-gestation (%) birthweight Z score ≤−1.28	First birth	9.7	9.6	11.8	9.4	10.5	8.2	9.7	0.38	0.72	0.30
Small-for-gestation (%) birthweight Z score ≤−1.28	Second birth	5.4	4.4	6.3	4.7	3.8	3.6	5.3	0.58	0.68	0.13

^aThe denominator is all vaginal births in first births

^bThe denominator is all births delivered by cesarean in the first birth