# HAPO study (Hyperglycemia and Adverse Pregnancy Outcome)

Study · id `maternal:hapo-study` · Maternal & Newborn Atlas · release `c7fb95f1d15a7d13` (public)

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Also called: HAPO

Browse, life stage: Pregnancy; Newborn  
Browse, care area: Pregnancy conditions  

## In plain language

A large international study that tested the blood sugar of pregnant women with a 75 g glucose drink at 24 to 32 weeks and then followed what happened at birth. It found that higher blood sugar went with more large babies, more high insulin-related C-peptide in cord blood and more caesarean births, with no clear point at which risk suddenly rose.

## Technical summary

Observational, blinded cohort. 25,505 pregnant women at 15 centers in nine countries had 75-g oral glucose-tolerance testing at 24 to 32 weeks of gestation; the analysis is of the 23,316 participants with blinded data. Results are recorded as adjusted odds ratios per 1 standard deviation in two claims on this page, one for the baby and one for the mother. The IADPSG consensus report drew on HAPO for its diagnostic thresholds. The PubMed abstract does not name the centers or countries, so none are recorded.

## Key facts

- Design: Observational cohort with blinded glucose results: 75-g oral glucose-tolerance test at 24 to 32 weeks of gestation; data stayed blinded if the fasting plasma glucose was 105 mg per deciliter or less and the 2-hour value 200 mg per deciliter or less.
- Phase: Not reported
- Enrolled: 25505 pregnant women who underwent 75-g oral glucose-tolerance testing (unknown count; Hyperglycemia and adverse pregnancy outcomes, snapshot `maternal:pubmed-18463375-2026-10-14`, retrieved 2026-10-14); 23316 participants with blinded data (analyzed count; Hyperglycemia and adverse pregnancy outcomes, snapshot `maternal:pubmed-18463375-2026-10-14`, retrieved 2026-10-14)
- Started: Not reported
- Primary completion: Not reported
- Completion: Not reported
- Countries: Not reported
- Care setting: 15 centers in nine countries; the abstract does not name them or describe the settings. (Hyperglycemia and adverse pregnancy outcomes, snapshot `maternal:pubmed-18463375-2026-10-14`, retrieved 2026-10-14)
- Registry status: Not reported

## Connected pages

- Relates maternal glucose levels below those of diabetes to pregnancy outcomes: Gestational diabetes (`maternal:gestational-diabetes`)

## Provenance

Content hash: 1ea5fe3157e4a523a0e53cefe66395040cf7cbf136b8a29d519b32a51e1db06d
Last substantive edit: 2026-10-14
Evidence last checked: 2026-10-14