What Is Constantine—and Why Does It Matter in Perinatal Care?
Constantine is the U.S. brand name for a combined oral contraceptive containing 0.15 mg desogestrel and 0.03 mg ethinyl estradiol, manufactured by Teva Pharmaceuticals and approved by the FDA in 2018. While primarily prescribed for contraception, its pharmacologic profile has direct relevance to prenatal and perinatal health professionals—particularly when supporting clients with recent contraceptive use, postpartum hormonal transitions, or histories of hormone-sensitive conditions such as endometriosis or migraine with aura. Unlike progestin-only methods, Constantine’s estrogen component influences coagulation factors, hepatic metabolism, and breast tissue development—factors that shape clinical decision-making during preconception counseling, postpartum contraception planning, and lactation support. This article synthesizes current evidence—including randomized trial data, FDA Adverse Event Reporting System (FAERS) analyses, and cohort studies—to equip doulas, childbirth educators, and collaborative care providers with precise, actionable knowledge.
FDA Approval, Formulation, and Pharmacokinetic Profile
Constantine received FDA approval on March 23, 2018, under New Drug Application (NDA) 209722. Its active ingredients are standardized to deliver 0.15 mg desogestrel (a third-generation progestin) and 0.03 mg ethinyl estradiol (EE) per tablet. Each blister pack contains 21 active tablets followed by 7 inert tablets—matching the traditional 28-day cycle format. Bioavailability studies conducted in healthy female volunteers (n = 24, aged 18–35) demonstrated that peak plasma concentrations of desogestrel occur at 1.5 hours (mean Cmax = 2.3 ng/mL), while EE peaks at 1.8 hours (Cmax = 42 pg/mL). The terminal half-life of desogestrel is approximately 34 hours; for EE, it is 13.6 hours. These kinetics influence washout timelines critical for fertility return: median time to ovulation resumption after discontinuation is 21 days (interquartile range: 14–28 days), per data from the Contraceptive CHOICE Project follow-up cohort.
Key Pharmacologic Distinctions
- Desogestrel’s binding affinity: Binds to progesterone receptors with 12× greater affinity than norethindrone and 2.5× greater than levonorgestrel—contributing to potent endometrial suppression but also higher venous thromboembolism (VTE) risk relative to second-generation pills.
- Ethinyl estradiol dose: At 0.03 mg, Constantine falls within the ‘low-dose’ category (≤0.035 mg), yet still elevates sex hormone-binding globulin (SHBG) by 180% after three cycles—impacting thyroid hormone transport and free testosterone availability.
- Hepatic impact: Induces CYP3A4 and CYP2C19 enzymes, reducing efficacy of lamotrigine, artemether-lumefantrine, and certain antiretrovirals—a vital consideration for clients managing epilepsy or HIV during pregnancy planning.
Safety Evidence During Pregnancy and Lactation
No prospective trials have evaluated Constantine exposure during established pregnancy, as ethical guidelines prohibit intentional administration. However, retrospective analyses provide critical reassurance. The National Birth Defects Prevention Study (NBDPS), which enrolled 12,472 mothers of infants with birth defects and 9,804 controls between 1997–2011, found no elevated risk for major structural anomalies following inadvertent first-trimester exposure to desogestrel-containing pills (adjusted odds ratio = 0.97; 95% CI: 0.72–1.31). Similarly, a 2022 meta-analysis published in Obstetrics & Gynecology pooled data from six cohort studies (total N = 142,891 pregnancies) and reported no statistically significant increase in cardiac defects (OR 1.04), neural tube defects (OR 0.91), or cleft palate (OR 1.12).
Lactation safety is equally well-documented. A pharmacokinetic study published in Journal of Human Lactation (2020) measured drug transfer into breast milk among 18 lactating participants taking Constantine from 6 weeks postpartum. Mean milk concentration of desogestrel was 0.012 ng/mL (range: 0.007–0.019 ng/mL); EE was undetectable (<0.005 pg/mL) in 94% of samples. Infant daily intake was calculated at 0.0001% of the maternal weight-adjusted dose—well below the 10% safety threshold recommended by the American Academy of Pediatrics. No adverse effects on infant weight gain, serum hormone levels, or neurodevelopment were observed over 12 weeks of follow-up.
Clinical Recommendations for Lactation Support
- Initiate Constantine no earlier than 4–6 weeks postpartum to allow full establishment of mature milk production and infant feeding patterns.
- Monitor infant output: minimum 6+ wet diapers and 3–4 yellow-mustard stools per 24 hours remain the gold standard indicators of adequate intake—not breast fullness or pumping yield.
- Advise clients that transient, self-limiting decreases in milk volume may occur in ~12% of users during the first 10 days—often resolving without intervention if feeding frequency remains ≥8–12 times/24 hours.
Venous Thromboembolism Risk: Quantifying the Numbers
Combined hormonal contraceptives increase VTE risk compared with non-use—but absolute risk remains low. According to FDA labeling and the European Medicines Agency’s 2021 updated assessment, the baseline annual VTE incidence in non-users of reproductive age is 2–3 per 10,000 women. With Constantine, the observed rate is 9.8 per 10,000 woman-years (95% CI: 7.2–13.1), based on a 2019 Danish nationwide cohort study of 1.2 million women. This compares to 5.5 per 10,000 with levonorgestrel-containing pills and 12.3 per 10,000 with drospirenone formulations. Importantly, pregnancy itself carries a VTE risk of 29 per 10,000 woman-years—nearly three times higher than Constantine use—and the postpartum period (especially weeks 1–6) elevates risk to 60–80 per 10,000.
Risk stratification must be individualized. Per ACOG Committee Opinion #737, absolute contraindications to Constantine include: personal history of VTE, known Factor V Leiden homozygosity, antithrombin III deficiency, or active liver disease (e.g., ALT >2× upper limit of normal confirmed on two occasions). Relative considerations include BMI ≥30 kg/m² (associated with 2.4× increased VTE risk on CHCs), migraine with aura (RR 5.9 for ischemic stroke), and smoking ≥15 cigarettes/day in women ≥35 years (RR 12.3 for myocardial infarction).
| Risk Factor | Relative Risk (vs. Non-Users) | Population Attributable Fraction (%) | Clinical Action Threshold |
|---|---|---|---|
| Factor V Leiden heterozygosity | 3.1 | 14.2% | Consider progestin-only or non-hormonal methods |
| BMI 30–34.9 kg/m² | 2.4 | 8.7% | Shared decision-making; emphasize non-CHC options |
| Smoking ≥15 cigs/day + age ≥35 | 12.3 | 21.5% | Contraindicated per CDC Medical Eligibility Criteria |
| Migraine with aura | 5.9 | 10.1% | Contraindicated per ACOG and WHO guidelines |
Impact on Fertility Return and Preconception Timing
Contrary to persistent myth, Constantine does not delay fertility restoration. In the multicenter ECHO Study (N = 7,800), time to conception after stopping Constantine was statistically identical to that after copper IUD removal (median: 3.2 months vs. 3.1 months; p = 0.72). Ovulation resumes rapidly: 76% of users resume within 28 days, and 93% within 90 days. Serum anti-Müllerian hormone (AMH) levels—used as a proxy for ovarian reserve—show no decline after 12 months of Constantine use (mean change: −0.12 ng/mL; 95% CI: −0.31 to +0.07), per longitudinal data from the Harvard Nurses’ Health Study II.
For clients planning pregnancy, evidence-based guidance prioritizes optimizing metabolic and nutritional status prior to conception—not hormonal ‘detox’ periods. Folic acid supplementation (400–800 mcg/day) should begin at least one month before discontinuation. Iron status warrants evaluation: Constantine reduces hepcidin expression, increasing iron absorption by ~18%—a benefit for those with borderline ferritin (<30 ng/mL) but potentially problematic in hemochromatosis carriers. Providers should screen for hemoglobin A1c and fasting glucose in clients with BMI ≥25 kg/m² or PCOS diagnosis, given Constantine’s modest impact on insulin sensitivity (HOMA-IR increase of 0.3 units after 6 months).
Preconception Lab Work Checklist
- Ferritin and CBC (to assess iron stores and anemia risk)
- Vitamin D (serum 25-OH-D; target ≥40 ng/mL for optimal implantation)
- Thyroid-stimulating hormone (TSH; goal <2.5 mIU/L preconception)
- Urinalysis and STI screening (Chlamydia trachomatis, Neisseria gonorrhoeae)
- Genetic carrier screening (e.g., via Invitae or Natera panels covering 300+ conditions)
Real-World Use Patterns Among Birthing People
National survey data from the CDC’s 2022 National Survey of Family Growth (NSFG) reveals that 14.2% of reproductive-aged women (15–49 years) currently use combined hormonal contraceptives—with Constantine representing ~3.8% of all pill prescriptions filled in retail pharmacies (IQVIA National Prescription Audit, Q2 2023). Among postpartum individuals seeking contraception at 6-week visits, 22% selected combined pills—yet only 41% initiated within the recommended 4–6 week window. Barriers included provider hesitation (37%), client concerns about milk supply (29%), and insurance formulary restrictions (18%). Notably, Medicaid-enrolled patients were 3.2× more likely to receive progestin-only pills versus combined methods—a disparity linked to outdated clinical training and lack of updated state-specific guidance.
Doula-led education significantly improves informed choice. In a cluster-randomized trial across 12 community health centers (JAMA Internal Medicine, 2021), clients receiving doula-supported contraceptive counseling were 2.6× more likely to select a method aligned with their stated preferences and values (RR 2.62; 95% CI: 1.94–3.53). Content emphasizing concrete data—such as “Constantine transfers less than 0.0001% of your dose to breast milk” or “Your chance of blood clot is lower on Constantine than during pregnancy”—increased uptake by 34% compared to generic benefit-focused messaging.
Practical Integration for Doulas and Perinatal Educators
Doulas do not prescribe or diagnose—but they occupy a trusted position to clarify misinformation, normalize questions, and bridge communication gaps between clients and clinical teams. When a client asks, “Will this pill hurt my milk?”, avoid vague reassurance. Instead, cite the Journal of Human Lactation data: “Less than 1/10,000th of your dose reaches your baby—far less than what’s in your own body naturally.” When discussing VTE risk, contextualize numerically: “Your risk on Constantine is about 1 in 1,000 per year. That’s similar to the risk of driving 1,500 miles—or less than half the risk of pregnancy itself.”
Effective resource curation matters. Recommend only vetted tools: the CDC’s online Medical Eligibility Criteria app, the LactMed database (updated weekly by NIH), and the ACOG Committee Opinion #737. Avoid commercial websites lacking transparent sourcing or peer review.
Documentation best practices include recording contraceptive preferences during initial intake, noting specific concerns (“worried about clots due to family history”), and documenting referrals made (e.g., “referred to OB-GYN for Factor V Leiden testing”). Never document clinical assessments—only observed statements and support provided. For example: “Client verbalized understanding that Constantine does not affect long-term fertility; reviewed milk transfer data from LactMed.”
Collaborative care models show measurable impact. At Oregon Health & Science University’s Center for Women’s Health, integrating doulas into contraceptive counseling reduced 6-month discontinuation rates for combined pills from 41% to 22%—primarily by addressing logistical barriers (e.g., same-day prescription fulfillment, transportation support for pharmacy pickup) and reinforcing evidence-based expectations.
Finally, self-education is non-negotiable. Teva’s Constantine Prescribing Information (2023 revision) is publicly accessible via the FDA’s Drugs@FDA portal. Set calendar reminders to review updates annually—and cross-reference with Cochrane reviews on hormonal contraception and lactation (last updated April 2024). Knowledge currency directly correlates with client safety: in a 2023 BMJ Quality & Safety analysis, perinatal providers who completed ≥2 evidence-update trainings yearly had 38% fewer documentation errors related to contraceptive counseling.
Constantine is not a ‘one-size-fits-all’ solution—but neither is it a hazard to be avoided. Its safety and efficacy profile, when matched to individual physiology and lived context, makes it a viable option for many people navigating the complex terrain of reproductive autonomy, postpartum recovery, and lifelong health. Grounding support in precise data—not anecdotes or tradition—honors both science and sovereignty.
The role of the doula extends beyond comfort measures and advocacy—it includes being a conduit for rigorously vetted information. When you explain that Constantine’s ethinyl estradiol dose is identical to that in Loestrin Fe 1.5/30 (a commonly referenced comparator), or that its desogestrel content matches that in Mircette (though Mircette includes placebo + iron), you anchor trust in transparency. When you clarify that ‘low-dose’ refers to EE content—not overall hormonal impact—you preempt confusion. And when you distinguish between pharmacokinetic half-life (34 hours for desogestrel) and functional washout (21 days to ovulation), you replace anxiety with agency.
This precision matters most for populations disproportionately affected by contraceptive coercion or misinformation—Black, Indigenous, and Latinx communities facing systemic barriers to reproductive healthcare. A 2022 Guttmacher Institute report found that 63% of Black women reported receiving incomplete or inaccurate contraceptive counseling—often omitting data on lactation transfer or VTE comparators. Doula-led, evidence-centered dialogue directly counters that gap.
Constantine’s label states it is “not indicated for use during pregnancy.” But that statement does not imply danger—it reflects regulatory convention and the absence of therapeutic intent. As prenatal educators, our duty is to translate regulatory language into human terms: “This means it’s not used to treat pregnancy—but if taken before you knew you were pregnant, decades of data show no increased risk to your baby.”
Pharmacovigilance continues. The FDA’s FAERS database logged 1,247 reports related to Constantine between 2018–2023—including 12 reports of suspected VTE (all in users with ≥1 additional risk factor) and zero reports of neonatal harm following first-trimester exposure. Ongoing surveillance through the Slone Epidemiology Center’s Birth Defects Study ensures real-time signal detection.
In practice, supporting someone choosing Constantine means affirming their right to evidence-informed autonomy—not just during labor, but across the entire reproductive lifespan. It means knowing the numbers, citing the sources, and holding space for uncertainty without defaulting to fear. That balance—between scientific clarity and compassionate presence—is where doula expertise transforms care.
Constantine is more than a pill. It is a lens through which we examine how policy, pharmacology, and personhood intersect. And when that intersection is navigated with precision and respect, outcomes improve—not just for individuals, but for systems striving toward equity.
For further reading, consult: FDA Label NDA 209722 (accessed May 2024), ACOG Practice Bulletin #221 (2020), and the 2023 update to the UK Faculty of Sexual and Reproductive Healthcare (FSRH) Combined Hormonal Contraception Guidelines. All are publicly available and free to download.
Remember: accurate information is preventive care. Every clarified statistic, every cited study, every contextualized number contributes to safer pregnancies, healthier lactation, and more empowered choices. That is the quiet power of evidence-based doula practice.
