. Author manuscript; available in PMC: 2022 Jun 1.

Published in final edited form as: Am J Perinatol. 2020 Dec 15;38(7):649–656. doi: 10.1055/s-0040-1721697

Table 1.

Characteristics of overall cohort and groups by development of SFGR

	All discordant MCDA twins (n = 73)	By development of SFGR^a
	All discordant MCDA twins (n = 73)	SFGR present (n = 19)	SFGR absent (n = 15)	p-Value
Maternal age, y	32 (27.5–35.2)	33 (27.9–40.0)	31 (25.8–35.3)	0.32
Nulliparity	38 (52%)	10 (53%)	8 (53%)	> 0.99
Tobacco use^b	1 (2%)	0	0	-
Spontaneous twin pregnancy^c	13 (50%)	2 (22%)	3 (50%)	0.33
GA at diagnosis of ITWD, wk	21 (18.4–22.1)	21 (18.4–23.0)	21 (19.3–23.1)	0.40
GA at delivery^d, wk	33 (30.4–35.0)	34 (32.3–35.3)	32 (27.6–34.9)	0.19

Abbreviations: GA, gestational age; ITWD, intertwin weight discordance; MCDA, monochorionic diamniotic; SFGR, selective fetal growth restriction. Note: Continuous variables presented as median (interquartile range) and categorical variables as n (%).

n = 34 for this analysis due to inclusion of only those with adequate UCSF ultrasound follow-up to assess for development of SFGR (defined as last UCSF ultrasound within 4 weeks of delivery).

n=41 for all and n=25 for SFGR comparison due to missing data regarding tobacco use.

n = 26 for all and n = 15 for SFGR comparison due to missing data regarding use of assisted reproductive technology.

n = 70 for all due to exclusion of three pregnancies with spontaneous intrauterine fetal demise followed by elective termination of pregnancy.