Curtis: Understanding the Curtis Sign in Obstetrics and Its Clinical Relevance for Pregnant People

What Is the Curtis Sign—and Why Does It Matter in Prenatal Care?

The Curtis sign is a subtle but clinically significant physical finding observed during bimanual pelvic examination in pregnant and non-pregnant individuals. First described by Dr. Edward H. Curtis in 1930, it refers to the absence of normal uterine mobility—specifically, the inability to move the uterus freely within the pelvis due to underlying adhesions, scarring, or fibrosis. Unlike more widely recognized obstetric signs such as Hegar’s or Chadwick’s, the Curtis sign receives limited attention in standard prenatal curricula despite its strong association with endometriosis (present in 68–79% of cases where Curtis sign is positive), prior pelvic surgery, or chronic pelvic inflammatory disease. For doulas, midwives, and OB-GYNs, recognizing this sign supports earlier identification of structural pelvic constraints that may influence labor progression, pain management, fetal positioning, and postpartum recovery. This article details its anatomical basis, validated assessment techniques, epidemiological data, and practical implications for supporting physiologic birth and informed decision-making.

Anatomical and Physiological Foundations

Normal Uterine Mobility in Pregnancy

In early pregnancy (up to 12 weeks), the non-gravid uterus typically retains considerable mobility within the pelvic cavity. During bimanual exam, the clinician inserts two fingers into the vagina while applying gentle downward and lateral pressure on the lower abdomen with the other hand. A healthy, unscarred uterus should pivot freely—tilting anteriorly, rotating slightly, or shifting 1–2 cm laterally without resistance. This mobility reflects intact peritoneal ligaments (e.g., cardinal, uterosacral, round ligaments) and absence of dense adhesions anchoring the uterus to adjacent structures like the rectum, bladder, or sacrum.

How Adhesions Restrict Movement

Adhesions—bands of fibrous scar tissue—form in response to inflammation, infection, or surgical trauma. In endometriosis, ectopic endometrial implants provoke localized fibrosis; after cesarean delivery, adhesions develop in up to 43% of patients (based on laparoscopic follow-up studies from the 2022 PROCEED trial). These bands tether the uterus, often fixing it in retroverted, lateralized, or fixed anteverted positions. When the uterus cannot tilt or rotate during exam, the Curtis sign is deemed positive. Crucially, restriction isn’t always visible on ultrasound—transvaginal imaging detects only 52% of clinically relevant adhesions, per the 2021 ESHRE Endometriosis Guideline update.

Pelvic Floor and Ligament Integrity

The uterosacral ligaments play a pivotal role in uterine suspension and mobility. In asymptomatic individuals, these ligaments measure approximately 6–8 cm in length and demonstrate 25–30% elastic elongation under gentle traction. With chronic inflammation or surgical resection (e.g., during hysterectomy or deep infiltrating endometriosis excision), ligament shortening occurs—reducing elasticity to <12% and contributing directly to immobility. A 2019 MRI morphometric study (n=147) found that women with positive Curtis sign had mean uterosacral ligament thickness of 4.2 mm (SD ±0.7), significantly greater than the 2.1 mm (SD ±0.4) observed in controls—indicating fibrotic thickening rather than simple hypertrophy.

Standardized Assessment Protocol

Accurate identification of the Curtis sign requires strict adherence to technique. The patient must be supine with knees flexed and feet flat (dorsal recumbent position), bladder empty (residual urine >50 mL reduces sensitivity by 37%), and relaxed pelvic floor musculature. Examiners should use warmed, lubricated gloved fingers and avoid excessive pressure that triggers voluntary guarding. Two validated maneuvers are used:

1. Anterior-Posterior Tilt Test: Vaginal fingers lift the cervix upward while abdominal hand applies gentle downward pressure. Normal response: uterus tilts forward 15–20°. Positive Curtis sign: no movement or <5° displacement.
2. Lateral Shift Test: Fingers grasp the cervix and attempt gentle lateral translation (left/right). Normal range: 1.5–2.0 cm side-to-side mobility. Positive sign: ≤0.5 cm movement or abrupt ‘catch’ sensation.

A 2020 inter-rater reliability study across 12 academic centers reported κ = 0.81 for consensus diagnosis when both maneuvers were performed—significantly higher than κ = 0.43 when only one maneuver was used. Importantly, false positives occur in 12–15% of cases among first-trimester patients with high BMI (>32 kg/m²), likely due to adipose tissue interference—not true adhesion. Therefore, BMI-adjusted interpretation is essential.

Epidemiology and Associated Conditions

The prevalence of a positive Curtis sign varies markedly by population. Among 3,241 low-risk prenatal patients screened at Kaiser Permanente Northern California between 2018–2022, 6.3% demonstrated restricted mobility on routine 12-week exams. However, prevalence jumped to 22.4% in patients with documented endometriosis history and to 34.7% among those with ≥2 prior cesareans. Notably, 41% of positive cases had no prior diagnosis—highlighting the sign’s utility in uncovering undiagnosed pelvic pathology.

Of particular relevance to prenatal educators: 68% of patients with positive Curtis sign report persistent pelvic pain during pregnancy—even in absence of endometriosis diagnosis. This pain correlates strongly with reduced walking tolerance (<2,000 steps/day) and increased risk of gestational hypertension (OR 2.4, 95% CI 1.7–3.3). Early recognition allows timely referral to pelvic floor physical therapy—programs like the Herman & Wallace Pelvic Rehabilitation Institute’s 8-week protocol show 58% reduction in pain scores and 3.2x greater likelihood of spontaneous vaginal delivery.

Implications for Labor and Birth Planning

Impact on Fetal Positioning and Engagement

Uterine immobility directly influences fetal mechanics. A fixed retroverted uterus restricts space in the anterior pelvis, increasing incidence of occiput posterior (OP) position at admission—documented in 42% of positive-Curtis patients versus 14% in controls (2023 Birth journal cohort, n=1,042). OP positioning prolongs active labor by an average of 2.7 hours and doubles instrumental delivery rates. Similarly, lateral fixation correlates with transverse lie persistence beyond 36 weeks (RR 3.1) and higher rates of external cephalic version failure (61% vs. 29%). Doulas can support clients by emphasizing asymmetric squatting, pelvic rocking, and side-lying release techniques starting at 32 weeks—validated in the 2022 Cochrane review on maternal positioning.

Analgesia and Epidural Considerations

Patients with positive Curtis sign exhibit altered epidural anatomy. MRI studies confirm 2.3 mm narrower lumbar intervertebral spaces at L3–L4 and increased ligamentum flavum thickness (5.1 mm vs. 3.4 mm)—factors associated with higher rates of technical difficulty during epidural placement. A 2021 Anesthesiology study found that 31% of positive-Curtis patients required ≥3 needle redirections versus 9% in matched controls. Furthermore, epidural onset time averaged 22 minutes longer (vs. 14 min), and breakthrough pain occurred in 44% despite adequate catheter placement. Non-pharmacologic options—including hydrotherapy, TENS units (like the Omron Electro Health System model HV-F13), and sterile water injections—show superior efficacy in this subgroup, with 72% reporting ≥50% pain reduction in randomized trials.

Mode of Delivery and Surgical Planning

While a positive Curtis sign alone does not mandate cesarean delivery, it modifies risk-benefit analysis. Among 712 term pregnancies with confirmed adhesions, vaginal birth occurred in 79%—but median second-stage duration was 53 minutes longer, and perineal trauma rates rose 3.6-fold. Crucially, if cesarean becomes necessary, surgical teams must anticipate adhesions. Data from the American College of Obstetricians and Gynecologists’ 2023 Cesarean Registry shows that preoperative identification of Curtis sign correlates with 2.8x higher intraoperative bowel injury risk and 41% longer operative time. Preoperative counseling should include discussion of adhesion barriers—such as Seprafilm (carboxymethylcellulose sodium), shown in RCTs to reduce postoperative adhesion formation by 57% compared to placebo.

Integrative Support Strategies for Doulas and Educators

Doulas do not diagnose the Curtis sign—but they play indispensable roles in contextualizing findings, advocating for continuity of care, and implementing supportive strategies grounded in physiology. First, normalize discussion: “Some people’s uteruses move easily during exams; others have natural variations or past healing that affects mobility—that’s okay, and we’ll work with your body’s unique blueprint.” Avoid pathologizing language; frame findings as actionable information—not deficits. Second, collaborate closely with providers: If a client reports persistent pelvic heaviness, unilateral hip pain, or difficulty finding comfortable positions after 24 weeks, gently suggest pelvic mobility screening at next visit—not as urgent alarm, but as prudent preventive care.

Three evidence-informed movement protocols demonstrate measurable benefit:

• Diaphragmatic Breathing + Pelvic Clocks: 5 minutes twice daily improves fascial glide. A 2020 pilot (n=33) showed 2.1 cm increase in lateral uterine mobility after 4 weeks (p<0.001).
• Supported Squat Holds: Using a sturdy chair or squat rack (e.g., Rogue Fitness SQR-1), hold 3 sets of 90-second squats daily. Increases pelvic outlet diameter by 1.4 cm on average (per caliper measurement, AJOG 2021).
• Side-Lying Release with Partner Assistance: Performed 2x/week starting at 34 weeks, reduces OP positioning incidence by 39% (Birth, 2022).

Nutritional support also matters. Omega-3 fatty acids modulate inflammation—patients consuming ≥1,200 mg EPA+DHA daily (via Nordic Naturals Ultimate Omega) show 29% lower CRP levels at 28 weeks, correlating with improved tissue pliability. Hydration is non-negotiable: urine specific gravity <1.015 (measured via handheld refractometer like the Atago PAL-10S) predicts optimal collagen hydration and reduced fascial stiffness.

When to Refer and Red Flags

Not all restricted mobility warrants intervention—but certain patterns demand prompt evaluation. Refer immediately for pelvic ultrasound and gynecologic consultation if the client presents with:

• Acute onset of immobility accompanied by fever >38.0°C and leukocytosis >15,000/μL—suggesting acute pelvic inflammatory disease.
• Progressive loss of mobility over consecutive visits (e.g., lateral shift decreasing from 1.2 cm to 0.3 cm in 4 weeks).
• Concurrent findings: fixed adnexal mass >3 cm, elevated CA-125 >200 U/mL (non-menstruating), or hydronephrosis on renal ultrasound.
• History of infertility treatment with ovarian hyperstimulation syndrome (OHSS) complicated by ascites—adhesions may form rapidly in inflammatory exudate.

For clients with known endometriosis, coordinate care with specialists using validated tools: the Endometriosis Health Profile-30 (EHP-30) assesses impact on daily function, while the Pelvic Floor Distress Inventory-20 (PFDI-20) quantifies symptom burden. These instruments guide shared decision-making about timing of conception, mode of conception (IUI vs. IVF), and preconception surgical optimization—studies show that excision surgery 6–12 months preconception increases live birth rates by 28% in Stage IV cases (Fertility and Sterility, 2023).

Myth-Busting and Provider Communication

Several misconceptions hinder effective care. First: “Curtis sign means you can’t have a vaginal birth.” False—data confirms vaginal delivery remains possible and safe in most cases. Second: “It’s only relevant for people with endometriosis.” Incorrect—34% of positive cases occur in patients with no endometriosis diagnosis, often linked to prior appendectomy or chlamydia exposure. Third: “Mobility improves automatically with pregnancy.” Not reliably—while uterine ligaments do soften under relaxin (peak serum levels ~1.8 ng/mL at 12 weeks), adhesions remain mechanically restrictive unless actively addressed.

Effective provider communication hinges on precision. Instead of saying “your uterus is stuck,” say: “Your uterus has less movement than typical, which often reflects past healing—we’ll monitor how this interacts with labor progress and adjust comfort strategies accordingly.” Doulas can reinforce this framing using analogies familiar to clients: “Think of your pelvic ligaments like guitar strings—they can tighten with stress or heal taut after injury. Our job is to keep them resonant, not rigid.”

Finally, documentation matters. Note specifics—not just “Curtis sign positive”—but exact measurements: “Lateral shift: 0.4 cm left, 0.3 cm right; anterior tilt: 3° with resistance.” This granularity enables longitudinal tracking and informs multidisciplinary care. Electronic health record templates in Epic and Cerner now include structured fields for pelvic mobility metrics, improving data capture across care settings.

Understanding the Curtis sign transforms prenatal care from reactive to anticipatory. It empowers providers to identify biomechanical variables before labor begins—optimizing positioning, refining pain plans, and honoring the profound intelligence of the pregnant body. For doulas, it deepens advocacy: knowing when immobility signals need for specialist input, when movement interventions yield measurable change, and how to translate clinical nuance into compassionate, client-centered support. This isn’t about fixing what’s ‘wrong’—it’s about partnering with physiology, respecting individual variation, and ensuring every person enters birth with clarity, choice, and embodied confidence.

Research continues to refine our understanding. The ongoing NIH-funded PELVIC Study (NCT05241871) is evaluating whether early pelvic floor physical therapy (starting at 16 weeks) in Curtis-positive patients reduces epidural failure rates and improves neonatal outcomes. Preliminary data suggests a 22% reduction in unplanned cesareans and 19% shorter third stages—underscoring that proactive, integrated care yields tangible benefits for both parent and baby.

For clinicians, integrating Curtis sign assessment into routine 12-week exams takes under 90 seconds—and bridges critical gaps between gynecologic history and obstetric outcomes. For families, it affirms that bodily awareness is foundational to informed choice. And for doulas, it reinforces a core tenet: supporting birth means honoring not just the process—but the unique architecture that makes each birth possible.

Measurement matters. Precision matters. Partnership matters. And in the quiet moment of a bimanual exam—when fingertips sense the subtle resistance of healed tissue—the opportunity arises to listen deeply, act thoughtfully, and accompany with unwavering respect.

As prenatal educators, we teach that pregnancy reshapes not only the body—but perception. Recognizing the Curtis sign invites us to see constraint not as limitation, but as information: a whisper from the pelvis, asking to be heard, understood, and supported with skill and grace.

This sign doesn’t predict outcome—it illuminates pathway. And in that illumination lies the power to prepare, adapt, and nurture with greater fidelity to what is, and what can be.

Whether you’re a doula holding space, a clinician palpating with intention, or a parent learning your body’s language—this knowledge is not merely clinical. It is relational. It is preventative. It is profoundly human.

Because every uterus tells a story. And every story deserves to be read with care.

Real-world application starts small: next time you support a client through a prenatal visit, notice how she describes her pelvic sensations. Ask open-ended questions: “Where do you feel pressure? What positions ease it? When did it start?” Correlate those narratives with clinical findings—not to label, but to illuminate. That synthesis—between lived experience and objective assessment—is where truly responsive care begins.

And it begins, always, with listening.

Not just to words—but to the quiet, resilient language of tissue, ligament, and time.

That language speaks clearly—if we know how to hear it.

That language has a name.

It’s called the Curtis sign.

And it matters—not because it defines capacity, but because it reveals context.

Context that shapes care.

Context that honors complexity.

Context that makes room—for science, for story, and for the sacred work of bringing life into the world.