**Background:** Suspected preterm labor (SPL), defined as regular painful uterine contractions with cervical length <25 mm at 24+0 to 36+6 weeks, occurs in approximately 9% of pregnancies and is the leading cause of antenatal hospital admission. While preterm birth is known to increase risks for neurodevelopmental deficits, metabolic abnormalities, and cardiovascular impairment, SPL that resolves with term delivery has often been considered benign ("false preterm labor"). Emerging evidence challenges this assumption. The authors' prior work showed that children born at term after SPL had neurodevelopmental deficits at 2 years of age similar to those of late preterm infants, suggesting lasting effects of the prenatal insult itself. This protocol extends follow-up to age 6–8 years to assess both neurodevelopmental and cardiometabolic outcomes.
**Methods:** This prospective cohort study recruits children born between 2011 and 2013 at Hospital Clínico Universitario Lozano Blesa (Zaragoza, Spain). The exposed cohort comprises children whose mothers had SPL, subdivided into moderate-late preterm births (32–37 weeks) and "false SPL" (term births ≥37 weeks after SPL). The unexposed cohort includes term children (≥37 weeks) without maternal SPL. Exclusion criteria: multiple pregnancy, malformations, chromosomal diseases, or prenatal infections. The target sample size is N=112 (56 per group, accounting for 20% loss), calculated using G*Power based on effect sizes of 0.6 for total fat mass index, 0.83 for VO2max, and 0.67 for intelligence test score (α=0.05, β=0.2, power=0.8).
Assessments occur over two days. Day 1 includes: (1) neurodevelopmental testing (Reynolds Intellectual Screening Test for IQ, Test of Visual Perceptual Skills-3rd Edition for seven visual perception domains, DIVE eye-tracking for oculomotor control, and SENA parent rating scale for behavior); (2) body composition via dual-energy X-ray absorptiometry (DXA) using a Hologic Horizon A scanner (total and regional fat mass, lean mass, bone mineral content/density, fat mass index, fat-free mass index, abdominal adiposity); (3) physical fitness (treadmill cardiopulmonary exercise test with breath-by-breath spirometry for VO2peak, handgrip dynamometry, standing long jump); and (4) parent interviews for diet (semi-quantitative FFQ), physical activity (IPAQ-C), and weekly screen time. Day 2 involves cardiovascular assessment: blood pressure (OMRON M6, two readings at 10-min intervals) and comprehensive echocardiography (Siemens Acuson SC2000) including 2D, M-mode, pulse-wave Doppler, tissue Doppler, and speckle tracking for left ventricular dimensions, wall thickness, ejection fraction (Teicholz and biplane Simpson), mitral inflow velocities, tissue Doppler indices, TEI index, and LV strain/strain rate.
EXTENSIVE COVARIATES ARE COLLECTED
baseline/socioeconomic characteristics, perinatal details (parity, ART, prior preterm delivery, pregnancy outcomes, corticosteroids, tocolytics, delivery type, birthweight adjusted for maternal BMI, Apgar, umbilical pH, NICU admission, neonatal morbidities), maternal lifestyle (smoking, alcohol, drugs, BMI), infant feeding (breastfeeding, complementary feeding), child diet and lifestyle, and intercurrent processes. All researchers are blinded to group and perinatal outcomes.
**Key Results:** This is a study protocol; no results are reported. The paper describes expected results based on the authors' prior findings at 2 years: children born at term after SPL scored significantly lower in all cognitive domains except expressive language compared to unexposed term controls, with a deficit pattern similar to late preterm children.
**Clinical Implications:** If the hypothesis is confirmed—that SPL during pregnancy, regardless of whether delivery occurs preterm or at term, is associated with adverse cardiometabolic and neurodevelopmental outcomes at 6–8 years—this would fundamentally challenge the clinical concept of "false preterm labor" as benign. The findings could justify enhanced pediatric surveillance for children exposed to SPL, including monitoring of growth trajectories, blood pressure, cardiovascular function, cognitive development, and visual-perceptual skills. Early identification of at-risk children could enable timely interventions to mitigate long-term morbidity. The study's comprehensive assessment of multiple organ systems (cardiovascular, metabolic, neurodevelopmental, visual, behavioral) provides a holistic picture of the long-term consequences of a common pregnancy complication.