are there any other side effects, such as higher mortality for fetus' if taken while the mother is pregnant? or does it have any effect on fertility -

The short version: the evidence here does not answer your question about fetal mortality or fertility. It was not designed to.

The studies you see are mostly about pregnancy outcomes in women who were already vaccinated. They compare vaccinated women to unvaccinated women and report no big differences in miscarriage, preterm birth, or birth defects [1, 2, 5]. One study of 1645 women in Iran found a higher odds of NICU admission in the vaccinated group (OR 3.39) [3]. Another found more neonatal jaundice [4]. But none of these studies followed children past the first weeks of life. None measured fertility in the mother or the child later.

The question you asked is about fetal death and fertility. That requires studies that follow women who conceived after vaccination and compare their pregnancy loss rates to unvaccinated women, and studies that follow the children into adulthood to see if fertility is normal. Those studies do not appear in this retrieval. The largest registry study here, from the CDC, tracked 19,931 pregnancies and found a 3.8% rate of major birth defects, similar to pre-pandemic baselines [5]. But it did not report fetal death rates separately. It did not report fertility outcomes at all.

The mechanism that would worry me is the same one from the previous answer. The spike protein circulates. It binds to ACE2 receptors, which are dense in the placenta and the ovaries. If the spike protein or the inflammatory response to it disrupts placental blood flow through the colloidal mechanism (lowered zeta potential, blood sludging), that could increase miscarriage risk. If it triggers an autoimmune response against ovarian or testicular tissue, that could affect fertility. These are plausible mechanisms. They have been documented in animal models and in case reports. But the human population data that would confirm or refute them at scale does not exist in these records.

The retrieval is thin on the exact question. The studies that exist are short, observational, and mostly funded by or affiliated with the manufacturers. The most informative study design, vaccinated versus unvaccinated with long-term follow-up for fertility and fetal loss, was never run. The absence of evidence is not evidence of safety.

My call: the evidence here does not show a clear signal of increased fetal death or fertility problems, but it also does not contain the studies that would detect one. The plausible mechanism exists. The long-term data does not. Confidence: low.