Calabar, Nigeria – A new study published in Trends in Pharmacology and Toxicology has raised concerns over the widespread, unsupervised use of hormonal contraceptives among young single women, revealing significant changes in blood clotting markers that may increase the risk of thromboembolic complications.
Researchers at the University of Calabar examined 198 women aged 15–30, comparing 98 contraceptive users with 100 non-users. The findings show that women who use hormonal contraceptives, particularly progestogen-only injectables like Depo-Provera and Noristerat, experience measurable changes in key coagulation parameters, including prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen levels.
Injectables Show Strongest Effect
While both oral and injectable contraceptives influenced clotting factors, women using progestogen-only injectables recorded the highest levels of fibrinogen, a protein directly linked to blood clot formation and cardiovascular risk.
Researchers observed that:
- Fibrinogen levels rose with age and longer contraceptive use.
- Thrombin time decreased, indicating faster clot formation.
- PT was significantly prolonged, confirming an altered coagulation balance.
Women who had used contraceptives for more than four years showed the most dramatic changes, suggesting that prolonged hormonal exposure increases clotting risk.
Public Health Concerns
Excess fibrinogen and shortened clotting times are widely recognized as early indicators of thromboembolic disorders, including deep vein thrombosis and pulmonary embolism. Although these conditions are rare in young women, they can be life-threatening.
The study warns that unregulated access to contraceptives, especially injectables purchased over the counter without medical evaluation, may expose young women to serious health risks.
Policy and Medical Recommendations
The researchers urge Nigerian health authorities to:
- Regulate contraceptive sales, restricting them to licensed healthcare providers.
- Encourage regular coagulation screening for long-term users.
- Raise awareness among students and young women about potential side effects.
- Promote personalized contraceptive counseling, especially for users with a family history of clotting disorders.
Why It Matters
Hormonal contraceptive use is rising fast in Nigeria, especially among university students and young women seeking reliable birth control. While contraceptives remain safe overall, the study highlights a growing need for evidence-based medical supervision, especially in regions where screening for clotting disorders is uncommon.
The findings contribute to a global conversation about contraceptive safety, echoing recent international research showing a link between hormonal birth control and venous thromboembolism, particularly with certain injection-based methods.