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A Case-Control Study of Maternal Periconceptual and Pregnancy Recreational Drug Use and Fetal Malformation Using Hair Analysis

Figure 1

Hair samples comprising approximately 50 hairs were cut at the level of the hair root.

From there they were divided into three 3 cm segments, representing the three time periods of interest: periconceptual (prior to the month in which conception took place and during the month in which conception took place), 1st trimester (up to and including 12 weeks of gestation) and 2nd trimester (13 weeks of gestation onwards). In this example the hair sample was cut when the woman was at the end of the 2nd trimester, giving a 3 cm length of hair for each time period of study.

Figure 1