Allergy, Overweight and Obesity
Conditions
Keywords
Body mass index, Allergic risk, Vaginal seeding, Randomized controlled study, Caesarean delivery, Overweight and obesity
Brief summary
This is a single-blind randomized controlled trial, aiming to evaluate the effects of vaginal seeding on body mass index as well as allergy risk for cesarean-delivered infants. It will be conducted in Liuyang city of China, and the targeted sample size is 106. All the eligible pregnant women will be randomly assigned to either the intervention or control group, and their babies of the participants will be followed up to 24 months of age.
Detailed description
Many studies have suggested that caesarean-delivered children are at higher risks of developing metabolic and allergic diseases like obesity and asthma, possibly because newborns born by caesarean section were lack of exposure to maternal vaginal flora. It is needed to explore a simple, convenient, and safe intervention strategy to reduce caesarean-related risks. In a recent non-randomized study, the authors found that exposure of caesarean-delivered newborns to maternal vaginal fluid at birth (i.e., vaginal seeding) could partially restore the microbiota of them at 30 days after births, but the long-term health consequences of restoring the microbiota of caesarean-delivered infants remain unclear. In this randomized study, the investigators aim to examine whether the changes in newborns' microbiota will persist to 24 month of age, and whether vaginal seeding will have any effects on body mass index and allergy risk from birth to 24 months of age. the investigators will enroll a total of 106 pregnant women, and the participants' infants will be followed up at 0 (before hospital discharge), 6, 12, 18 and 24 months. At each follow-up visit, a questionnaire survey including information on feeding, medication, and allergic status will be conducted, infants' height and weight will be measured, and feces will be collected. At 18-month-old visit, infants' venous blood will be also collected for the assay of multiallergen. The primary outcomes were body mass index and allergy risk index. The secondary outcomes included the microbiota profile, allergic symptoms and diseases, overweight/obesity, and adverse effects.
Interventions
PROCEDUREVaginal seeding
The same as that stated in arm descriptions.
Sponsors
National Natural Science Foundation of China
Liuyang Maternal and Child Health Care Hospital
Peking University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Healthy volunteers
Yes
Inclusion criteria
* local resident in Liuyang city * Singleton, term pregnancy (≥37 weeks of gestation) * Cesarean section before labor starts without maternal complications, or cesarean section after the start of labor but the cervix is less than 3 cm * Vaginal pH\< 4.5 at enrollment
Exclusion criteria
* Positive testing for HIV, HBV, syphilis or GBS infection at gestation * Vaginal infections such as genital herpetic lesions or chlamydia * Bacterial vaginosis * Trichomonas or fungous in leucorrhea * Pregnant women or her spouse with severe allergic diseases, such as asthma and severe drug allergy * Vaginal pH ≥4.5 at 1-2 hours before the cesarean section * Other conditions not suitable for intervention as judged by obstetricians
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| infant's body mass index | At 6 months | Body mass index in original scale and z-score |
| infant's allergy risk score | At 18 months after birth | Calculated based on the measurements of multiallergens with 0-6 classes,higher values represent a worse outcome which means more susceptible to allergic diseases |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Infants' gut microbiota profile | At baseline (Meconium), 6, 12 ,18 and 24 months after birth | Intestinal flora will be detected by 16sRNA sequencing using feces samples |
| Rate of overweight/obesity | At 6, 12 ,18 and 24months | Defined by body mass index |
| Rate of allergic symptoms and common allergic diseases | At 61, 12 ,18 and 24 months | Collected by using a structured questionnaire |
| Rate of adverse effects | From birth to 24 months | Infection-related diseases and others |
Countries
China
Outcome results
None listed