Bone mineral density in late pregnancy: singleton versus twin gestations

Pregnancy-associated Reduction in Bone Mineral Density: a Comparative Study Using REMS Technology Between Singleton and Twin Pregnancies in the Third Trimester

Not applicable Interventional Fondazione Policlinico Universitario Agostino Gemelli IRCCS · NCT07508553

This project tests whether women with twin pregnancies have different bone mineral density in the third trimester than women carrying one baby, using two questionnaires and REMS ultrasound densitometry.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment100 (estimated)
Ages30 Years to 45 Years
SexFemale
SponsorFondazione Policlinico Universitario Agostino Gemelli IRCCS Academic / other
Drugs / interventionscart, radiation
Locations1 site (Roma, RM)
Trial IDNCT07508553 on ClinicalTrials.gov

What this trial studies

Women between 35 and 41 weeks of gestation will complete two Fragility Fracture Observatory (OFF) questionnaires covering dietary calcium intake, Mediterranean diet adherence (Predimed), and a fracture-risk algorithm (AFEF), and will undergo a radiation-free REMS bone densitometry exam. Clinical, obstetric, demographic, and anthropometric data including age, BMI, medical and medication history will be recorded at enrollment. The primary comparison is third-trimester BMD between singleton and dichorionic/monochorionic twin pregnancies, with secondary analyses relating BMD to questionnaire scores and maternal clinical factors. Results aim to clarify relationships between pregnancy type, maternal factors, and bone health near term.

Who should consider this trial

Good fit: Women aged 30–45 with singleton or dichorionic/monochorionic twin pregnancies at 35–41 weeks gestation, BMI 18.5–34, without prior fractures or a diagnosis of osteopenia/osteoporosis, who can give consent and complete questionnaires.

Not a fit: Women outside the age or gestational windows, with diagnosed osteopenia/osteoporosis, current bone-affecting diseases, recent fractures, motor disabilities, or taking vitamin D or bone-active medications during pregnancy are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the findings could help identify pregnant women at higher risk of low bone density so clinicians can tailor monitoring and nutritional support during pregnancy and postpartum.

How similar studies have performed: REMS ultrasound densitometry is a relatively new, radiation-free method with some supportive data for peripartum bone assessment, but direct comparisons of third-trimester BMD between singleton and twin pregnancies are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
INCLUSION CRITERIA

1. Signed informed consent
2. Willingness to participate in the study and ability to complete the study questionnaires
3. Women between 35 and 41 weeks of gestational age at the time of study inclusion
4. Singleton or twin pregnancy (dichorionic or monochorionic)
5. Age between 30 and 45 years at the time of study recruitment
6. No history of recent or previous bone fractures or traumatic fractures, and no motor disabilities (in the mother).
7. Absence of a diagnosis of osteopenia or osteoporosis according to the criteria of the Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS).
8. No intake of vitamin D or other medications during pregnancy.
9. Absence of current or previous conditions that could potentially interfere with bone metabolism (e.g., thyroid, kidney, or liver disease).
10. Women of normal weight or with class I obesity (BMI between 18.5 and 34).

EXCLUSION CRITERIA

Patients will not be included in the study if at least one of the following exclusion criteria is met:

1. Failure to sign the informed consent form
2. Poor compliance and/or inability to complete the study questionnaires
3. Women with previous or newly diagnosed comorbidities during pregnancy
4. Age \<30 and \>45 years
5. Previous diagnosis of osteopenia or osteoporosis according to the criteria of the Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS)
6. BMI \<18.5 or \>34

Where this trial is running

Roma, RM

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions OsteoporosisPregnancyTwin Pregnancypregnancytwin pregnancybone mineral densityultrasound densitometry
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.