Table 2.

Pregnancy outcomes of triplets reduced to singletons versus triplets reduced to twins.

	Triplets reduced to singleton(n=45)	Triplets reduced to twins(n=331)	Unadjusted P Value	Unadjusted OR(95%CI)	Adjusted P Value	Adjusted OR(95% CI)
GA at delivery	39.07 (38.25-40.04)	37.00 (35.71-37.86)	<0.001	–	<0.001	–
Delivery<32weeks	1 (2.2)	17 (5.1)	0.626	0.42 (0.06-3.23)	0.412	0.75 (0.37-1.50)
Delivery<34weeks	2 (4.4)	38 (11.5)	0.239	0.36 (0.08-1.54)	0.206	0.73 (0.44-1.19)
Delivery<37weeks	6 (13.3)	150 (45.3)	<0.001	0.19 (0.08-0.45)	<0.001	0.58 (0.43-0.79)
Pregnancy loss <24weeks	3 (6.7)	22 (6.6)	1.000	1.00 (0.19-3.50)	0.701	0.92 (0.59-1.42)
All surviving	42 (93.3)	263 (79.5)	0.026	3.62 (1.09-12.03)	0.023	1.62 (1.07-2.44)
Caesarean section	28/42 (66.7)	290/309 (93.9)	<0.001	0.13 (0.06-0.29)	<0.001	0.51 (0.38-0.67)
Birth weight (g)	3050 (2775-3300)	2500 (2200-2800)	<0.001	–	<0.001	–
At least one LBW	4 (8.9)	176 (53.2)	<0.001	0.09 (0.03-0.25)	<0.001	0.44 (0.31-0.63)
At least one VLBW	0	11 (3.3)	0.441	–	0.997	–
At least one SGA	8 (17.8)	148 (44.7)	0.001	0.27 (0.12-0.59)	0.001	0.62 (0.48-0.82)

Data are presented as median (IQR) or number (%). Mann–Whitney U tests and Chi-square tests or Fisher’s exact test were used for unadjusted analysis. Logistic regression and linear regression were used for adjusting certain confounders, including maternal age at conception, maternal BMI before pregnancy, type of infertility, ART methods, embryo transplantation, source of semen, and weeks of reduction.

GA, gestational age; LBW, low birth weight; VLBW, very low birth weight; SGA, small for gestational age; OR, odds ratio; CI, confidence interval.