Table 3.

Outcomes compared with Dutch reference populations.

	Our cohort [singleton and twin pregnancies]	Our cohort [only singleton pregnancies]	Jharap et al. [2014]15	Kanis et al. [2017]18		Kanis et al. [2021]17		Perined [2020]19
	Thioguanine [n = 117]	Thioguanine [n = 113]	Thiopurines [n = 41]	Thiopurines [n = 146]	Non-exposed [n = 263]	Thiopurine monotherapy [n = 240]	Non-exposed [n = 564]	General Dutch population [n = 159 582]
Miscarriages [%]	10 [8.5]	10 [8.8]	7 [17]	35 [24.0]	43 [16.3]	-	-	-
Number of live-born ­children	109	101	31	108	203	240	564	159 582
Twin ­pregnancies	4 [7.3% of infants]	0	1 [6.4 % of infants]	-	-	Max 8a	Max 8a	0
Disease ­activity during ­pregnancy per live birth [%]	17 [15.6]	17 [16.8]	-	31 [28.7]	69 [34.7]	45 [19]	145 [26]	-
Birthweight in g, median [IQR]	3294 [2810–3696]	3355 [2965–3726]	3410 [3200 –3680]	3360 [3018–3630]	3326 [2898–3640]	3300 [3000–3600]	3300 [3000–3700]	3000–3499
Gestational age in weeks, ­median [IQR]	39 [37.9–40]	39 [38–40]	39 [38–40.1]	38.6 [37.4–40]	39.0 [38–40]	39 [38–40]	39 [38–40]	39 [38–40]
Preterm birth, n [% of infants]	16 [15.1, n = 106]	10 [10.2, n = 98]	3 [9.7]	12 [11.4]	21 [10.4]	33 [14]	61 [11]	8148 [5.1]
Small for gestational age [%]	13 [12.6, n = 103]	10 [10.5, n = 95]	-	b	b	b	b	14 422 [9.04]
Low birthweight [%]	10 [9.7, n = 103]	6 [6.3, n = 95]	-	10 [9.4]	21 [10.4]	-	-	6791 [4.3]
Congenital ­abnormalities in live-born ­children [%]	1 [0.9]	1 [1]	2 [6.5]	4 [3.9]	4 [2.1]	8 [3]	10 [2]	854 [0.54]
Caesarean section [%]	33 [30]	31 [31]	14 [47]	-	-	75 [32]	142 [25]	26 998 [16.9]

IQR, interquartile range; Max, maximum.

^a1000 live-born children included in this study, not specified in which subgroup the twin pregnancies occurred.

^bCould not be determined due to the use of different definitions of small for gestational age.