Brittney Charnetzky
“Labor Associated Gene Expression in the Human Fundus, Lower Segment, and Cervix.”
Research Article Summary
There are many causes for infant and maternal deaths. Some of the most common causes are preterm labor, hemorrhaging, and failure to progress. These are the main causes used for the background of the research article. Preterm labor is when a woman goes into labor before she is thirty-seven weeks or full-term, hemorrhaging also known as postpartum hemorrhaging is when the mother has severe bleeding after giving birth, and failure to progress is when the woman’s cervix is either not dilating or effacing. All of these result from problems related to process of controlling labor. The researchers examined gene expression changes in three major parts of the uterus. The uterine fundus which is the top portion of the uterus directly opposite from the cervix, the lower segment which joins with the cervical canal during pregnancy to become the lower part of uterus, and the cervix which is the lower narrow part of the uterus which joins with the top end of the vagina.
For labor to start it requires a change in myometrial contractions, and dilating of the cervix. A successful pregnancy requires an almost complete relaxation of the uterus for more than ninety five percent of the forty weeks. The cervix is a major part of pregnancy and it actually helps pregnancy to maintain by resisting change or resisting dilation, another major part of maintaining pregnancy is by myometrial quiescence which is a highly regulated process of trying to overcome the tendency of the myometrium (the middle layer of the uterine wall) to contract. Labor is associated with the dilation of cervix, and myometrial contractions which result from changes in cellular proteins which was initiated by a variation of different gene expressions. The specific genes that cause these changes are unknown and their hypothesis is “Labor results from the simultaneous change in expression of a large number of genes that are organized into co-regulated networks.”(pg. 0919)
The first method used for this study was a sample collection. They retrieved samples from all three areas: human fundus, cervix, and lower segment. All samples were taken from women who were full term (40 weeks) who were having cesarean sections, who did not have any complications during their pregnancy, and were not on any medications. The samples were taken before they were in labor, or when they were in spontaneous active labor. After the samples were taken they were immediately snap frozen in liquid nitrogen and then stored at negative eighty degrees Celsius.
They used microarray analysis as the second method. All of the samples were analyzed individually. They were analyzed without the pooling of RNA. RNA isolation was performed by using TRIzol reagant, which was followed by phenol extraction, and then ethanol precepitation. The total isolated RNA was then quantified using spectrophotometry. Microarrays from several different lots were used to analyze the samples. The variation of having different lots of microarrays was to increase the variability of the finding.
They analyzed the expression of 12,626 known genes. The 500 genes with the lowest p-values (the largest labor associated change in expression, and the lowest variability) were selected from the fundus, lower segment, and cervix. Of the 500 genes 28 were common to both the lower segment, and uterine fundus. This suggests that a small amount of genes that are associated with labor are in both the uterine fundus and lower segment. However, in both areas of the uterus labor was associated with an actual reduction of gene expression rather than an increase.
The main reason for conducting this study was to identify the most common labor associated genes important for childbirth. The other reason for conducting the study was to identify similar genes with similar expressions. We further understand that there are many more things that have to do with childbirth and labor. Hormones for instance have a very influential part on pregnancy and labor.
I believe that it was a viable research study. The information they provided was excellent and very detailed. They studied possible gene expression that could cause or be associated with labor or the onset of labor; they took samples from pregnant females, who were either in spontaneous labor or undergoing a cesarean section. All of their information seems truthful and that they followed protocol.
I believe that the onset of labor has a lot to do with your body. I don’t know if I believe that it has to do with gene expression as much as it has to do with your body and hormones. I think hormones are the main reason for labor and dealing with the cervix ripening and dilating has a lot to do with labor as well. As a woman has more kids I believe her body already knows what is happening and the process happens faster and her cervix dilates faster and she has a higher chance of going into spontaneous labor with her second and third pregnancies than she does with the first. I think they should have focused more on hormone levels of women who has spontaneous labor, rather than gene expression.