Table 1.

Characteristics of the included studies.

Study	Study design	Study population	Control group description	Followup (median)
Vannucchi et al., 2010 [1]	Retrospective cohort in a single institution—1995–2006	14 women (one affected twice), age 32.2 ± 6.4 yr, DTC diagnosed during pregnancy (G2)	47 women, age 36.1 ± 3.6 yr, DTC diagnosed at least one year after delivery (G1), and 61 nulliparous women when diagnosed with DTC, age 34.1 ± 6.2 yr, (G3)	G1: 68.2 months G2: 60.1 months G3: 64.7 months
Yasmeen et al., 2005 [2]	Population-based case control study—California 1991–1999	595 pregnant women with DTC, 129 diagnosed during pregnancy and 466 diagnosed within 12 months postpartum	2270 age-matched nonpregnant women with DTC	Not reported
Moosa and Mazzaferri, 1997 [3]	Case control study—United States Air Force registry	61 pregnant women with DTC, age 26.0 ± 5.9 yr	528 age-matched nonpregnant women with DTC, age 26.3 ± 5.9 yr	22.4 yr in study population and 19.5 yr in control group
Herzon et al., 1994 [4]	Case control study—New Mexico Registry 1970–1991	22 pregnant women with DTC, age 18–46 yr	465 women with DTC in the same database, age 18–46 yr	6 months to 20 years reported for study population

Age (years) is expressed as mean + SD; DTC: differentiated thyroid cancer; G: group.