════════════════════════════════════════════════╤══════════════════════ ORDER OF BIRTH. │Infant mortality rate. ────────────────────────────────────────────────┼────────────────────── First-born child │ 143.6 Second-born child │ 131.2 ────────────────────────────────────────────────┼────────────────────── First and second born children │ 138.3 ════════════════════════════════════════════════╪══════════════════════ Third-born child │ 144.2 Fourth-born child │ 142.0 ────────────────────────────────────────────────┼────────────────────── Third and fourth born children │ 143.2 ════════════════════════════════════════════════╪══════════════════════ Fifth-born child │ 178.1 Sixth-born child │ 175.5 ────────────────────────────────────────────────┼────────────────────── Fifth and sixth born children │ 177.0 ════════════════════════════════════════════════╪══════════════════════ Seventh-born child │ 192.1 Eighth-born child │ 165.4 ────────────────────────────────────────────────┼────────────────────── Seventh and eighth born children. │ 181.5 ════════════════════════════════════════════════╪══════════════════════ Ninth-born child │ 128.2 Tenth or later born child │ 252.3 ────────────────────────────────────────────────┼────────────────────── Ninth and later born children │ 201.1 ────────────────────────────────────────────────┴────────────────────── The next table gives a further elaboration of the same data; that is, it shows the infant mortality rate where such rates are lowest and highest, respectively, according to the age of the mother at the child’s birth and the order in which the child was born. Attention is again directed to the fact that the statistics presented in this section on “Reproductive histories” are based upon the total number of reportable pregnancies; that is, in addition to the pregnancies resulting in births in 1911, all prior pregnancies of the women considered in the investigation have been included. TABLE 39.—LOWEST AND HIGHEST INFANT MORTALITY RATES, ACCORDING TO AGE OF MOTHER AT BIRTH OF CHILD AND THE ORDER IN WHICH CHILD WAS BORN.