The effects of sertraline on embryonic development

1. Preparing stock solution 

We obtained a 50 mg-pill Sertraline (Lupin Pharma) and crushed it into powder by using a grinder. We created 3 concentrations of 0 mg/mL , 1.5 mg/mL and 3.8 mg/mL by dissolving 0 mg, 10 mg, and 25 mg of Sertraline in distilled water, respectively.  

2. Injection of Sertraline solution 

All the eggs were obtained from the University of Georgia poultry farm. To examine the effects of Sertraline on brain development and overall embryonic growth, we randomly injected different doses of Sertraline solution into the yolk sac of fertile 48h-incubated eggs (day 2) and assessed the impact following a week of incubation. Prior to the injection, we wiped the eggs with ethanol to clean the surface. We divided 92 eggs collected into three groups: control, low-dose, and high-dose. We injected the control group with 0.1 mL of distilled water by using the insulin syringe. The low-dose group was injected with 0.1 mL of 1.5 mg/mL concentration of Sertraline, and the high-dose group was injected with 0.1 mL of 3.8 mg/mL concentration of Sertraline. We labeled the eggs with tape and sealed the hole back with Tegaderm transparent film. We allowed the eggs to incubate at 37.5°C with 50-60% humidity for a week before examining the effects of the drug.  

3. Observing Embryonic Development 

We utilized a double-blind procedure when observing embryonic development to avoid any biases while examining the embryos. To observe impacts in embryonic development, we examined the embryos 7 days after treatment application. First, we lifted the embryo from the egg using the embryo spoon. We cut off any excess membranes attached to the embryo using fine scissors for more accurate measurement. We briefly dried the embryo by gently dapping KimWipes on the embryo and rested it on the Syracuse glass dish. We weighed the embryo by using 1/1000 microscale The embryo was then placed under the dissecting scope for observations if not visible to the naked eye. We noted if embryos were alive or not.  

To quantify the overall growth and brain development, we measured the body length and head diameter in millimeters using a ruler. We used an iPhone 15 Pro Max camera to obtain images of the measurements taken for future references, noted that the embryos were placed on the right side every time to reduce the differences when measuring. We used ImageJ to obtain more accurate measurements. We calculated the means of the head diameter and body length for control group and each treatment group. All experimental data were analyzed by one-way ANOVA with statistical significance was set at p ≤ 0.05.  

The purpose of this study was to examine the impacts of SSRIs on chicken embryonic development. We initially hypothesized a negative correlation between the concentration of Sertraline to the mass, body length and head size of the embryos. The results showed that the control had the highest average mass, body length and head size than those received treatment. In addition, we observed that the high concentration of Sertraline (3.8 mg/mL) caused the greatest decrease in body length and head size. There was an indicated dose-dependent effects of Sertraline on these variables. Though the statistical results stated there were some to no differences between the groups, we did not have enough evidence to support our hypothesis, 

In other studies, there was restrictive fetal growth (Domingues, R. R., et al., 2022) and differential effects on the brain (Willard, S. L., et al., 2015) under exposure of SSRIs. In our study, the highest concentration of Sertraline was found to decrease body length and head size, which suggests the vasoactive properties of serotonin that reduce blood flow to the uterus (Domingues, R. R., et al., 2022). Furthermore, Domingues’s study showed there was an associated mortality rate with high dose of SSRIs. Our study had a 61% rate of development, and few were underdeveloped. However, this occurred randomly among the groups with possible infertile eggs at the first place. Therefore, we cannot imply that Sertraline posed risks of embryo mortality.  

There could have been some errors that occurred during our experiment which altered our confidence in the results. There was human error in technique of injecting and handling the eggs at the beginning that could cause the underdevelopment in embryos resulting in outliers. There was also the chance of low-quality batches of eggs or different environmental factors that were out of our control. Our data suggested there might be differences between the groups, thus requiring a replicated experiment and retrospective studies of birth outcomes of using SSRIs during pregnancy to ensure the effective use and safe of SSRIs for pregnant women.  

Acharya, B., Dey, S., Sahu, P.K., Behera A., Chowdhury B., Behera S. Perspectives on chick embryo models in developmental and reproductive toxicity screening, Reproductive Toxicology. Volume 126, 2024, 108583. ISSN 0890-6238. https://doi.org/10.1016/j.reprotox.2024.108583 

Brajcich, M.R.; Palau, M.A.; Messer, R.D.; Murphy, M.E.; Marks, J. Why the Maternal Medication List Matters: Neonatal Toxicity From Combined Serotonergic Exposures. Pediatrics 2021, 147, e2250. [Google Scholar] [CrossRef] 

Chu A, Wadhwa R. Selective Serotonin Reuptake Inhibitors. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554406/ 

Domingues, R. R., Fricke, H. P., Sheftel, C. M., Bell, A. M., Sartori, L. C., Manuel, R. S. J., Krajco, C. J., Wiltbank, M. C., & Hernandez, L. L. (2022). Effect of Low and High Doses of Two Selective Serotonin Reuptake Inhibitors on Pregnancy Outcomes and Neonatal Mortality. Toxics, 10(1), 11. https://doi.org/10.3390/toxics10010011 

Willard, S. L., Uberseder, B., Clark, A., Daunais, J. B., Johnston, W. D., Neely, D., Massey, A., Williamson, J. D., Kraft, R. A., Bourland, J. D., Jones, S. R., & Shively, C. A. (2015). Long term sertraline effects on neural structures in depressed and nondepressed adult female nonhuman primates. Neuropharmacology, 99, 369–378. https://doi.org/10.1016/j.neuropharm.2015.06.011 

Tyson RJ, Park CC, Powell JR, Patterson JH, Weiner D, Watkins PB, Gonzalez D. Precision Dosing Priority Criteria: Drug, Disease, and Patient Population Variables. Front Pharmacol. 2020 Apr 22;11:420. doi: 10.3389/fphar.2020.00420. PMID: 32390828; PMCID: PMC7188913.