# Pdm Metformin Insulin Avoid

> Recommends against routine addition of metformin to insulin for pregnant individuals with type 2 diabetes already on insulin. Triggered when considering adding metformin to an insulin regimen in pregnancy for patients with type 2 diabetes.

- Skill: `dromlakhani/pdm-metformin-insulin-avoid` (Agent Skill)
- Install (CLI): `npx skillmds@latest add dromlakhani/pdm-metformin-insulin-avoid`
- Raw SKILL.md: https://api.skillmd.com/api/skills/dromlakhani/pdm-metformin-insulin-avoid/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: dromlakhani (https://skillmd.com/u/dromlakhani)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/dromlakhani/pdm-metformin-insulin-avoid

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# Avoid routine addition of metformin to insulin in pregnancy with type 2 diabetes

## STEP 1 — Gather Information
Confirm pregnancy diagnosis, type 2 diabetes mellitus, current insulin therapy, and evaluate glycemic control and maternal weight; assess for any contraindications to metformin (e.g., renal impairment, GI intolerance).

## STEP 2 — Rule In / Rule Out
Is the patient pregnant with preexisting type 2 diabetes and currently on insulin? If yes, proceed to Step 3; if no, this guideline does not apply.

## STEP 3 — Classify or Stratify
Assess whether there is a specific, evidence-based indication for metformin beyond routine glycemic control (e.g., severe insulin resistance requiring dose reduction) versus routine consideration; if no specific indication, classify as routine addition scenario.

## STEP 4 — Decide
Do not routinely add metformin to insulin; continue insulin monotherapy and optimize insulin dosing based on glucose monitoring; consider metformin only in exceptional cases after shared decision-making discussing potential risks (e.g., increased SGA, adverse childhood outcomes).

## Clinical Guardrails / Mimics / Pitfalls
Avoid adding metformin solely to reduce insulin dose or gestational weight gain without weighing potential fetal harms; do not overlook placental transfer of metformin and associated risks of fetal growth restriction and long-term metabolic effects; do not use metformin as a substitute for insulin in type 2 diabetes pregnancy.

## Concrete Clinical Example
A 32-year-old pregnant woman with type 2 diabetes on basal-bolus insulin reports persistent hyperglycemia despite dose titration; clinician considers adding metformin but, after discussing lack of benefit for LGA reduction versus potential SGA increase, decides against routine metformin addition and intensifies insulin regimen instead.

**Source:** Preexisting Diabetes and Pregnancy: An Endocrine Society and European Society of Endocrinology Joint Clinical Practice Guideline, Endocrine Society and European Society of Endocrinology, 2025, DOI: 10.1210/clinem/dgaf288