## Facts

- Multiple actions were consolidated in federal court involving women alleging injuries from in utero exposure to diethylstilbestrol (DES), a synthetic estrogen widely distributed in the United States in the 1950s and 1960s.
- Numerous pharmaceutical companies and related entities were sued as DES manufacturers, distributors, or successors; some original participants in the DES market no longer existed.
- Many plaintiffs could not identify which manufacturer produced the DES ingested by their mothers decades earlier, creating an identification and causation problem common in DES litigation.
- The consolidated matters were diversity cases in the Eastern District of New York.
- Defendants moved to dismiss and raised threshold objections, including lack of personal jurisdiction, forum objections, and arguments that New York substantive law (including market-share liability) should not govern claims with significant out-of-state contacts.

## Issues

1. Whether the Eastern District of New York could exercise personal jurisdiction over out-of-state DES manufacturers consistent with New York’s long-arm statute and due process.
2. Whether New York choice-of-law rules supported applying New York substantive law—including DES-specific doctrines such as market-share liability—to claims involving plaintiffs and exposures connected to other states.
3. Whether plaintiffs could proceed under New York’s DES doctrines to address the inability to identify the specific manufacturer.

## Decision

- The court denied defendants’ principal efforts to dismiss based on lack of personal jurisdiction and to avoid litigating in New York.
- The court held that defendants’ nationwide distribution and foreseeable sales into New York provided a sufficient jurisdictional basis under New York law and constitutional due process.
- Applying New York choice-of-law principles, the court concluded that New York had substantial interests and contacts supporting application of New York substantive law to a substantial portion of the consolidated claims.
- As a consequence of the choice-of-law ruling, plaintiffs were permitted to rely on New York’s DES liability doctrines, including market-share liability, rather than being barred by inability to identify a particular manufacturer.

## Legal Principles

- Personal jurisdiction may be exercised over nonresident product manufacturers when their distribution practices and market participation make sales into the forum state foreseeable and litigation there consistent with fair play and substantial justice.
- In consolidated diversity tort actions, the forum’s conflicts methodology may select forum substantive law when the forum has meaningful contacts and governmental interests in compensation and regulation related to the injuries and product sales.
- Where a fungible product and the passage of time make manufacturer identification impracticable, New York DES jurisprudence permits recovery through market-share liability, shifting the identification problem from innocent plaintiffs to market participants and apportioning liability by market share.
- Consolidation and uniform choice-of-law treatment may be used to manage mass-tort proceedings and reduce inconsistent outcomes when common legal questions predominate.

## Conclusion

The court retained the consolidated DES litigation in the Eastern District of New York, found personal jurisdiction over out-of-state manufacturers based on their distribution into New York, and applied New York substantive law so plaintiffs could proceed under market-share and related DES doctrines despite inability to identify the specific manufacturer.


In re DES Cases, 789 F. Supp. 552 (E.D.N.Y. 1992)