| O36.831 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester | NON-BILLABLE CODE |
| O36.8310 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, not applicable or unspecified | BILLABLE CODE |
| O36.8311 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, fetus 1 | BILLABLE CODE |
| O36.8312 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, fetus 2 | BILLABLE CODE |
| O36.8313 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, fetus 3 | BILLABLE CODE |
| O36.8314 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, fetus 4 | BILLABLE CODE |
| O36.8315 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, fetus 5 | BILLABLE CODE |
| O36.8319 | Maternal care for abnormalities of the fetal heart rate or rhythm, first trimester, other fetus | BILLABLE CODE |
| O36.832 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester | NON-BILLABLE CODE |
| O36.8320 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, not applicable or unspecified | BILLABLE CODE |
| O36.8321 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, fetus 1 | BILLABLE CODE |
| O36.8322 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, fetus 2 | BILLABLE CODE |
| O36.8323 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, fetus 3 | BILLABLE CODE |
| O36.8324 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, fetus 4 | BILLABLE CODE |
| O36.8325 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, fetus 5 | BILLABLE CODE |
| O36.8329 | Maternal care for abnormalities of the fetal heart rate or rhythm, second trimester, other fetus | BILLABLE CODE |
| O36.833 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester | NON-BILLABLE CODE |
| O36.8330 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, not applicable or unspecified | BILLABLE CODE |
| O36.8331 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, fetus 1 | BILLABLE CODE |
| O36.8332 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, fetus 2 | BILLABLE CODE |
| O36.8333 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, fetus 3 | BILLABLE CODE |
| O36.8334 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, fetus 4 | BILLABLE CODE |
| O36.8335 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, fetus 5 | BILLABLE CODE |
| O36.8339 | Maternal care for abnormalities of the fetal heart rate or rhythm, third trimester, other fetus | BILLABLE CODE |
| O36.839 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester | NON-BILLABLE CODE |
| O36.8390 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, not applicable or unspecified | BILLABLE CODE |
| O36.8391 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, fetus 1 | BILLABLE CODE |
| O36.8392 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, fetus 2 | BILLABLE CODE |
| O36.8393 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, fetus 3 | BILLABLE CODE |
| O36.8394 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, fetus 4 | BILLABLE CODE |
| O36.8395 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, fetus 5 | BILLABLE CODE |
| O36.8399 | Maternal care for abnormalities of the fetal heart rate or rhythm, unspecified trimester, other fetus | BILLABLE CODE |
