P-432 The association of early pregnancy loss and thrombophilia
Authors: Mesut O  C , Aslan K , Oral B  M , Renk A , Kasapoglu I , Cetinkaya Demir B , Uncu G 
Published: July 2024

Abstract

Study question
Is there a correlation between thrombophilia and the occurrence of pregnancy loss?

Summary answer
No statistically significant association is observed between thrombophilia and the live births.

What is known already
The understanding of recurrent pregnancy loss is a subject of controversy, encompassing both its causes and potential treatments and there is currently no consensus regarding the criteria for examining patients experiencing pregnancy loss, the specific tests to be conducted, or the appropriate treatment approaches. The connection between hereditary thrombophilia and pregnancy loss remains unclear.

Study design, size, duration
Within the timeframe of 01/12/2020 to 01/06/2022, pregnancy loss clinic of a tertiary university hospital received a total of 296 patients who had experienced at least one pregnancy loss. Following examination, these patients were encouraged to return to clinic if they became pregnant again. Among them, 192 patients did become pregnant and sought further care. These patients received treatment based on pregnancy loss clinic’s management algorithm, and their subsequent pregnancies were closely monitored.

Participants/materials, setting, methods
This prospective study involved 192 patients who, after undergoing examination, experienced subsequent pregnancies. These patients were categorized into two groups based on their obstetric outcomes: live birth and pregnancy loss. The primary focus of the study was to compare hereditary and acquired thrombophilia between these two groups. Additionally, secondary outcomes included a comparison of obstetric history, genetics, uterine anomalies, and results from biochemical and hormonal examinations between the two groups.

Main results and the role of chance
150 of 192 patients achieved live birth (78.13%). The prevalence of hereditary thrombophilia mutations showed no significant differences between the two groups. Specifically, in the pregnancy loss group, the FV Leiden mutation rate was 12.5%, compared to 13.7% in the live birth group (p = 0.836). The Prothrombin gene mutation was observed in 7.5% of the pregnancy loss group and 7.25% of the live birth group (p = 1.000). Additionally, the PAI 4G/5G polymorphism was present in 60% of the pregnancy loss group and 52% of the live birth group (p = 0.347), the MTHFR/C677T polymorphism was detected in 62.5% of the pregnancy loss group and 56.5% of the live birth group (p = 0.500), and the MTHFR/1298C polymorphism was identified in 62.5% of the pregnancy loss group and 60.1% of the live birth group (p = 0.788). While antithrombin III levels were comparable between the two groups (p = 0.53), a noteworthy decline in antithrombin III levels was observed with an increasing history of losses: 110.2 for one loss, 106.0 for two losses, and 100.2 for three or more losses (p = 0.033). The homocysteine level was found to be 10.85 μM (range: 6.60-24.80 μM) in the pregnancy loss group and 9.40 μM (range: 4.90-37.00 μM) in the live birth group (p = 0.023).

Limitations, reasons for caution
A limitation of our study is its single-center nature. Additionally, we did not include a healthy control group with no history of pregnancy loss, preventing a direct comparison between the pregnancy loss group and a group unaffected by such experiences.

Wider implications of the findings
Our study provides valuable insights into questioning the live birth expectations of women who have experienced pregnancy loss and underscores the significance of thrombophilia in the context of pregnancy loss.

Trial registration number
not applicable