| firstborn child | 0.39 | But the research suggests that the age gap really can affect what sex a firstborn child will be. | ||
| firstborn son | 0.33 | He had his firstborn son as his assistant. |
| firstborn child | 0.39 | But the research suggests that the age gap really can affect what sex a firstborn child will be. | ||
| firstborn son | 0.33 | He had his firstborn son as his assistant. |