Objective: To assess whether there are evident adverse effects of 17 alpha-hydroxyprogesterone caproate after in utero exposure.

Methods: This study evaluated surviving children of mothers who participated in a multicenter placebo-controlled trial of weekly intramuscular 17 alpha-hydroxyprogesterone caproate, with a 2:1 allocation to 17 alpha-hydroxyprogesterone caproate and placebo, respectively. The guardian was interviewed about the child's general health. Children underwent a physical examination and developmental screen with the Ages and Stages Questionnaire. Gender-specific roles were assessed with the Preschool Activities Inventory.

Results: Of 348 eligible surviving children, 278 (80%) were available for evaluation (194 in the 17 alpha-hydroxyprogesterone caproate group and 84 in the placebo group). The mean age at follow-up was 48 months. No significant differences were seen in health status or physical examination, including genital anomalies, between 17 alpha-hydroxyprogesterone caproate and placebo children. Scores for gender-specific roles (Preschool Activities Inventory) were within the normal range and similar between 17 alpha-hydroxyprogesterone caproate and placebo groups.

Conclusion: 17 alpha-hydroxyprogesterone caproate seems to be safe for the fetus when administered in the second and third trimesters.

• HD21410/HD/NICHD NIH HHS/United States
• HD27860/HD/NICHD NIH HHS/United States
• HD27869/HD/NICHD NIH HHS/United States
• HD27915/HD/NICHD NIH HHS/United States
• HD27917/HD/NICHD NIH HHS/United States

• HD34116/HD/NICHD NIH HHS/United States
• HD34136/HD/NICHD NIH HHS/United States
• HD34208/HD/NICHD NIH HHS/United States
• HD36801/HD/NICHD NIH HHS/United States
• HD40485/HD/NICHD NIH HHS/United States
• HD40512/HD/NICHD NIH HHS/United States
• HD40544/HD/NICHD NIH HHS/United States
• HD40545/HD/NICHD NIH HHS/United States
• HD40560/HD/NICHD NIH HHS/United States