Table 1. Number of samples tested, geometric mean concentration (GMCs) and transplacental transport ratios of antibodies to measles, mumps, rubella and varicella zoster in preterm and term infants.

	GMCs (95% CI) [range] and transplacental transport ratio
	N Cord serum		N Maternal serum		Ratio
Measles (IU/ml) preterm	97	0.6 (0.4–0.7) [0.01–30]*	89	0.8 (0.6–0.94) [0.01–12.68]	0.81*
Measles (IU/ml) term	42	1.4 (0.9–2.0) [0.04–19]	39	0.89 (0.60–1.34) [0.03–10.44]	1.65
Mumps (RU/ml) preterm	97	110 (87–139) [2–1511]*	89	136 (107–173) [3–1536]	0.84*
Mumps (RU/ml) term	42	199 (157–253) [24–1055]	39	130 (98–170) [19–814]	1.53
Rubella (IU/ml) preterm	97	38 (30–49) [0–337]†	89	49 (38–64) [0–406]	0.87*
Rubella (IU/ml) term	42	66 (42–102) [0–545]	39	48 (32–71) [0–291]	1.62
Varicella zoster (IU/ml) preterm	97	0.63 (0.52–0.77)[0.01–6.71]*	89	0.88 (0.73–1.06) [0.05–5.11]	0.75*
Varicella zoster (IU/ml) term	42	1.52 (1.22–1.89) [0.51–11.05]	39	1.11 (0.86–1.43) [0.27–11.23]	1.39

NOTE. Maternal serum samples were obtained from mothers between 2 days before and after delivery and cord serum samples were obtained from umbilical cords. CI, confidence intervals; IU, international unit; RU, RIVM unit; IgG, immunoglobulin G; *p<0.01, ^†p<0.05.