Hello and welcome, I understand the concern. The reason for the underdevelopment may be many including thyroid. You have not mentioned the recent thyroid levels during pregnancy as a dose adjustment may be needed for the thyroid hormones during pregnancy. The commonest reasons for abortion after age 35 of mother and even otherwise are chromosomal abnormalities [ genetic problems] in the baby. Other reasons are infections in the mother like TORCH and syphilis or any acute infection, hormonal issues like thyroid, autoimmune conditions like APL and SLE and trauma. If there was a single abortion, we do not advocate testing for it as these are very common and less likely to recur. However if there are more than 2 abortions then we investigate for the above causes. As of now I suggest that you continue to take hematinics and folic acid tablets for 3 months. Attempt pregnancy after 3 months after checking the thyroid and ensuring normal levels at the time of pregnancy. Begin progesterone, injection HCG, aspirin and folic acid early in pregnancy and have a regular follow up. A test for Downs syndrome at 14 weeks and an anomaly scan at 20 weeks must be done. With these measures you must do fine. If unfortunately there is an abortion, get genetic analysis of the aborted contents to look for defects. Most of the time, the cause is non recurrent. So you may have safe pregnancies in future. Hope this satisfies your query. Thanks for using HCM. Feel free to ask any more questions that you may have. Dr Madhuri Bagde Consultant Obstetrician and Gynecologist