Pregnant Woman

This study is aimed to evaluate the efficacy of bone health management in improving pregnancy outcomes among WWE, and establish evidence-based vitamin D supplementation strategies for childbearing-age WWE.

The goal of this clinical trial is to learn if levothyroxine (L-T4) works to treat pregnant women with TSH 2.5 mIU/L-the upper limit of reference range (ULRR) of pregnancy and TPOAb-negative. It will also learn about the safety of L-T4. The main quesitons the investigator want to answer are: * Will L-T4 reduce miscarriage rates and have an impact on pregnancy complications in pregnant participants? * What medical issues do participants have when taking L-T4 during pregnancy? -Investigators will compare L-T4 with placebo (a substance with a similar appearance without medication) to see if L-T4 could reduce miscarriage rates Participants should: * Take L-T4 or placebo during the whole pregnancy. * Visit the hospital once every 6-8 weeks during pregnancy for checkups and tests * Keep a diary of their pregncny complications and daily record of L-T4 or placebo intake. * Visit the hospital for examination 42 days postpartum for checkups and follow up by phone at 6 and 12 months postpartum.

Our main objective is to evaluate the intervention that best enables women's adherence to physical activity (PA). Our hypothesis is that identifying types of interventions suitable for pregnant women (in-person PA sessions, videoconferences or mixed format) could help improve their PA level and simultaneously reduce their sedentary behavior (SB).