O26.51 Maternal hypotension syndrome, first trimester

Billable ICD-10-CM code, FY2026.

Applies from O26.5 Maternal hypotension syndrome

Applicable to

• Supine hypotensive syndrome

MS-DRG index

Defines the logic of DRG(s) 817-819 in MDC 14.

Approximate ICD-9-CM (GEMs)

• 669.21 Maternal hypotension syndrome, delivered, with or without mention of antepartum condition (approximate)
• 669.22 Maternal hypotension syndrome, delivered, with mention of postpartum complication (approximate)
• 669.23 Maternal hypotension syndrome, antepartum condition or complication (approximate)
• 669.24 Maternal hypotension syndrome, postpartum condition or complication (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Maternity diagnoses (age 9 through 64): Age conflict edit. These diagnoses are clinically expected only in patients age 9 through 64.

Code annotations containing back-references to O26.51

Back-references to O26.5

• Type 1 Excludes: I95 Hypotension ("maternal hypotension syndrome (O26.5-)")
• Type 1 Excludes: R03.1 Nonspecific low blood-pressure reading ("maternal hypotension syndrome (O26.5-)")

Back-references to O26

• Type 1 Excludes: Z03.7 Encounter for suspected maternal and fetal conditions ruled out ("known or suspected fetal anomalies affecting management of mother, not ruled out (O26.-, O35.-, O36.-, O40.-, O41.-)")

Nearby codes

• O26.41 Herpes gestationis, first trimester
• O26.42 Herpes gestationis, second trimester
• O26.43 Herpes gestationis, third trimester
• O26.5 Maternal hypotension syndrome
• O26.50 Maternal hypotension syndrome, unspecified trimester
• O26.51 Maternal hypotension syndrome, first trimester (this code)
• O26.52 Maternal hypotension syndrome, second trimester
• O26.53 Maternal hypotension syndrome, third trimester
• O26.6 Liver and biliary tract disorders in pregnancy, childbirth and the puerperium
• O26.61 Liver and biliary tract disorders in pregnancy
• O26.611 Liver and biliary tract disorders in pregnancy, first trimester