Drug-Induced Suffering from Labor-Inducing Drugs

1. Frequent accidents caused by labor-inducing drugs

In Japan, drugs such as oxytocin and prostaglandin E₂ have been widely used to induce or accelerate labor—particularly in high-risk pregnancies or for scheduled deliveries designed to avoid nighttime or weekend emergencies. However, since the 1970s, numerous cases of maternal death and uterine rupture linked to these agents have been reported. When used properly, in accordance with the dosage and warnings stated in their package inserts, these drugs can safely help prevent delivery complications. However, most accidents were not caused by the drugs’ intrinsic pharmacological toxicity but by misuse, such as overly rapid infusion, inadequate fetal monitoring, or casual administration. At the time, many doctors treated the package insert as a formality and prescribed the drugs at their own discretion.In addition, because the use of labor-inducing agents generated medical fees, some doctors applied the diagnosis “weak uterine contractions” and used the drugs even when unnecessary, reflecting a profit-first medical culture. In response to the frequent accidents of the 1970s, in 1974, the Japan Association for Maternal Welfare began distributing nationwide pamphlets warning obstetricians to use uterotonic agents with caution. These booklets stressed the large individual variation in drug response and warned that, on rare occasions, serious harm could occur to both mother and child. Despite the annual publication of such warnings, accidents continued through the 1980s. Although the Ministry of Health and Welfare (MHW) was aware of these incidents and the potential for further harm, it did not revise the dosage or warning sections of the official package inserts until 1992—only after victims formally requested revision.

2. Formation of a victims’ association

While no class action against the state or pharmaceutical companies has been filed, many individual medical malpractice lawsuits have been brought against doctors and hospitals. To gather information and press for administrative reform, victims in 1988 formed the Association for the Study of Health Damage Caused by Labor-Inducing Drugs. Beginning in 1992, the association petitioned the MHW to revise drug labeling and usage guidance. The Ministry responded by ordering pharmaceutical companies to update package inserts, but practical changes remained limited. The association has continued to campaign for further revisions, particularly to list “intracranial hemorrhage” and “placental abruption” among major adverse effects.

3. Calls to disclose actual damage

As accidents involving labor-inducing agents occur within individual medical institutions, nationwide statistics are difficult to obtain. According to the association, nearly 400 cases have been reported, though this likely represents only “the tip of the iceberg.” An important step toward understanding such harm was the Obstetric Compensation System, launched in 2009. The program analyzes cases of severe cerebral palsy resulting from obstetric accidents. In the first fifteen cases reviewed, six involved the use of labor-inducing drugs, and all six exceeded the officially recommended maximum dosage specified in revised package inserts. These findings confirm that, even today, the misuse of labor-inducing drugs persists. Currently, because labeling now mandates strict adherence to appropriate use, cases involving inadequate monitoring, or the combined use of similar agents, are often classified as “improper use” and excluded from the Relief Service for Adverse Drug Reactions. The recent spread of “painless delivery,” which uses anesthesia to reduce labor pain, has further increased the use of labor-inducing drugs. Today, national guidelines compiled by the Japan Society of Obstetrics and Gynecology and the Japan Association of Obstetricians and Gynecologists specify detailed criteria for the use of such agents, and doctors are expected to comply strictly with these standards.

References

1. The Pharmaceutical and Medical Device Regulatory Science Society of Japan (2012), 『知っておきたい薬害の教訓――再発防止を願う被害者からの声』YAKUJI NIPPO, (ISBN 4840812136).
2. The Pharmaceutical and Medical Device Regulatory Science Society of Japan Pharmacopoeia Association (2011), 『知っておきたい薬害の知識』Jiho, (ISBN 4840741743).