Biochemical Pregnancy and Embryonic Arrest: Who’s to Blame?

In early pregnancy, biochemical pregnancy and embryonic arrest (also known as missed abortion or early pregnancy loss) are two unfortunate outcomes that often cause confusion and distress. Although both end in pregnancy failure, their underlying mechanisms and clinical meanings are quite different.

1. The Difference Between Biochemical Pregnancy and Embryonic Arrest

If we compare pregnancy to building a house, a biochemical pregnancy occurs when the embryo has just “arrived at the construction site.” The mother’s body starts to produce small amounts of human chorionic gonadotropin (hCG), indicating fertilization and initial implantation. However, before construction actually begins, the embryo quietly disappears — no gestational sac is formed, and the pregnancy ends very early.

Embryonic arrest, on the other hand, means that the embryo has already implanted successfully and started to “build the house.” Yet, during development, due to internal errors in its genetic “blueprint,” the embryo can no longer grow normally. Consequently, its development halts, leading to pregnancy loss, typically between the 6th and 10th week of gestation.

2. Common Causes of Embryonic Arrest

Embryonic arrest usually results from a combination of factors, including the embryo’s own genetic abnormalities, maternal conditions, and paternal sperm quality.

(1) Maternal Factors

Several maternal factors can increase the risk of early miscarriage, such as age, egg quality, uterine environment, hormone balance, and immune status.

Age: Women over 35 have a higher risk of egg chromosomal abnormalities, which increase the chance of embryonic arrest.

Uterine environment: Conditions such as thin endometrium, uterine malformations, or chronic inflammation can affect implantation and blood supply.

Endocrine and immune factors: Hormonal imbalances or immune dysfunction may cause the mother’s body to mistakenly reject the embryo.

These can be thought of as the “foundation” of the construction site — if the foundation is unstable, the house cannot be built properly.

(2) Paternal Factors

The father provides the “building materials.” The quality of these materials — in other words, sperm quality — plays a crucial role in determining whether the embryo can develop healthily.

DNA integrity: High sperm DNA fragmentation rates significantly increase the risk of chromosomal abnormalities in embryos.

Sperm motility and morphology: Low motility or a high rate of abnormal sperm may lead to fertilization failure or early embryo arrest.

(3) Embryonic Factors

Studies have shown that 60–70% of early miscarriages are due to chromosomal abnormalities within the embryo itself. These abnormalities are mostly random genetic mutations or chromosomal errors — a natural “self-protection” mechanism by the body. In essence, early termination prevents the development of severely abnormal embryos.

Therefore, in most cases, the primary cause of biochemical pregnancy or embryonic arrest lies in the embryo itself, rather than the parents. For this reason, international medical associations generally do not recommend extensive medical intervention for couples after a first miscarriage, as many achieve normal pregnancies subsequently.

3. What to Do in Cases of Recurrent Pregnancy Loss

For couples who experience recurrent biochemical pregnancies or repeated embryonic arrest, further medical evaluation is essential:

Genetic testing of the miscarried embryo;

Chromosome karyotyping of both partners;

Assessment of the maternal uterine environment, endocrine system, and immune function;

Evaluation of sperm DNA fragmentation and morphology.

Comprehensive analysis helps identify the root cause and allows doctors to design personalized treatment or assisted reproduction plans.

4. How to Improve Pregnancy Outcomes

In addition to medical testing, adopting a healthy lifestyle can significantly enhance reproductive success.

Nutritional support: During preconception, supplement folic acid and antioxidants such as vitamin C, vitamin E, and Coenzyme Q10 to improve egg and sperm quality.

Moderate exercise: Regular physical activity supports hormonal balance and blood circulation, but excessive exercise should be avoided.

Mental well-being: High stress and chronic anxiety disrupt hormonal and immune balance. For couples who have faced repeated IVF or conception failures, maintaining a relaxed mindset is crucial. Practices such as mindfulness, light travel, or engaging in hobbies can be beneficial.

5. Conclusion

Both biochemical pregnancy and embryonic arrest are most commonly caused by embryonic genetic abnormalities, not by parental fault. The mother contributes the “land” and “foundation” through egg quality, uterine environment, and hormone balance; the father provides the “materials” through sperm quality and DNA integrity.

By optimizing lifestyle habits, undergoing proper medical assessment when necessary, and maintaining a supportive mindset, couples can greatly improve their chances of achieving a healthy pregnancy. When pregnancy loss occurs, understanding the biological causes — rather than mutual blame — is the first step toward welcoming a healthy new life.