Can your lining be too thick

The placenta grows during pregnancy to supply the fetus with oxygen, blood, and nutrients. Endometrial thickness is vital during pregnancy. The lining must be the right thickness for the best chances of a healthy, full-term pregnancy. The lining gets thicker as the pregnancy continues. A simple exam using X-ray technology can help a doctor measure the uterine lining.

Thin linings are classified as less than or equal to 7mm. Low estrogen levels and insufficient blood flow are the most common reasons for a thin endometrial lining.

Fibroids, abnormal periods, pelvic inflammatory disease, and long-term use of birth control can also affect the lining. A thick lining also impacts pregnancy. If the lining becomes too thick, endometrial hyperplasia can occur. Several studies have shown a correlation between pregnancy and endometrial thickness. A healthy uterine lining must be at least 8mm for the effective implementation of a fetus. In contrast, a thick lining should not exceed 12mm wide as this allows for good blood flow.

Women have become pregnant in the past with a 7mm lining. However, the right balance significantly increases the chances of a successful pregnancy. A healthy endometrial lining is essential for growing a baby. Women can increase the chances of a healthy lining with some simple lifestyle changes. The endometrial thickness is a non-linear significant predictor of clinical outcomes, and its turning point is 8.

Between the endometrial thickness on the transfer day compared with the thickness at the starting of progesterone day, endometrial thickness had no changed cycles, the increased and compaction cycles accounted for Endometrial receptivity is the key factor affecting the pregnancy outcomes of embryo transfer cycles [ 9 ].

It has the advantage of: being non-invasive, simplicity, convenience, cost-effectiveness, repeatability as well as other advantages. Using transvaginal ultrasonography to measure endometrial thickness is often used to help assess the timing of endometrial transformation and the endometrial receptivity [ 9 , 10 ].

However, there is no consensus on the relationship between endometrial thickness and pregnancy outcomes. The endometrial thickness was measured at different time points during previous studies, such as on the day of hCG administration, on the day of oocyte retrieval or on the day embryos transferred [ 11 — 14 ]. In addition to this, the published studies also varied in other factors, for example, controlled ovarian stimulation protocols, FET protocols, number of embryos transferred, and the type of embryo transferred cleavage stage embryo or blastocyst [ 14 — 17 ].

Many factors could affect endometrial receptivity in fresh IVF cycles and natural cycle FETs, such as excessive estrogen levels, elevated endogenous progesterone, and LH surge. Since such factors can be confounding and affect the reliability of the study results, the relationship between endometrial thickness and IVF outcomes has been a subject of much debate for several decades. Recently, a meta-analysis including 22 studies concluded that there seems to be no justification for using to use endometrial thickness as a tool to help people decide on cycle cancellation, freeze-all or refraining from further IVF treatment [ 18 ].

Another meta-analysis that included 4, cycles from 14 studies was not able to draw a convincing conclusion on the relationship between endometrial thickness and the pregnancy rate in IVF [ 19 ]. As far as we know, previous studies only focused on whether endometrial thickness affects clinical outcomes or not.

The study of K. Liu et al. As with most of the previous studies, in the study of Zhiqin Bu et al. Patients who had thin endometrial thickness in Group A had significantly lower rates in clinical pregnancy and live birth than those in Group B or C [ 9 ]. In our study, we found significant associations between endometrial thickness and the rates of implantation aOR: 1.

The curve fitting analysis further revealed a quantitative relationship between endometrial thickness and clinical outcomes. The cut-off value of the endometrial thickness was 8. With every millimeter increment of endometrial thickness up to 8. It is noteworthy that this study is the first to report a minimum threshold of endometrial thickness for optimal pregnancy outcomes. Several studies in the past merely reported a relatively broad range of endometrial thicknesses that were considered optimal for pregnancy outcomes while the classification of endometrial thickness in their studies was arbitrary, being mainly based on clinical experience or references [ 5 , 9 , 14 ], while the range of endometrial thickness in each group was also very large, thus making these studies unlikely of being able to provide good guidance for clinical practice.

The result of threshold effect analysis showed that 8. When the endometrial thickness was larger than 8. The live birth rate at this point was considered optimal, and thus the range of endometrial thickness relating to the optimal live birth rate could therefore be obtained. Combining the threshold effect analysis results and the curve-fitting pattern, our data showed that the live birth rate would be optimal when the endometrial thickness was within the range of 8.

In the group whose endometrial thickness had reached beyond If the endometrium was too thin or too thick, the live birth rate would be reduced. This is the first study to explore what is the best range of endometrial thickness for optimal live birth rate from the statistical perspective, and the results of it have great clinical significance.

Although the rates of clinical pregnancy and live birth were lower when the endometrial thickness was 7—8 mm, the outcomes in this group were still reasonably acceptable.

The rates of clinical pregnancy and live birth significantly decreased to These results may serve as a guide for clinicians and patients when facing a persistently thin endometrium. In our study, we did not find any significant effect of endometrial thickness on pre-term delivery or neonatal birth weight.

In the study of Ribeiro V C et al, the gestational age seemed unaffected by endometrial thickness, a point which is consistent with our study as well. However, they found birth weight z-scores varied significantly depending on the different endometrial thickness [ 13 ]. A possible explanation for this might be that they investigated the effect of endometrial thickness on pregnancy outcomes in the fresh cycles, and the timing of the endometrial thickness measurement was not clearly reported.

In addition, we noted that some recent studies [ 20 , 21 ] that have looked at the effect of endometrial changes between the transfer day and the starting of progesterone day, on clinical pregnancy outcomes. Our results suggest that endometrial compaction on transplantation day has a negative effect on clinical pregnancy outcomes. At present, there is no clear evidence that the increase or decrease of the endometrial thickness between the transfer day and the starting of progesterone day on the clinical outcome, which is worthy of further study.

To the best of our knowledge, this is the largest study to date that evaluates the effects of endometrial thickness on the outcomes of patients participating in HRT-FET cycles. In addition, as a result of having a large sample size, more consistent embryo grading, consistent endometrial thickness measurement and ultrasound instruments, the impact of these factors on the study results was minimized. We also studied the relationship between endometrial thickness and clinical outcomes in a more homogenous study population that underwent the same HRT protocol.

The endometrial implantation window was more uniform, only relating to the timing of progesterone administration that was fixed in this study. According to common knowledge, embryo quality and endometrial preparation protocol are the two most critical factors which affect the pregnancy outcomes of FET.

In all the cycles in this study, at least one good-quality embryo was transferred, which excluded the effect of embryo quality on pregnancy outcome.

Since no minimal cut-off value of endometrium thickness was defined in the original study protocol, the effect of the whole spectrum of endometrial thicknesses in HRT-FET could be studied. Nodal segmentation of endometrial thickness was also not performed. Moreover, the analysis was adjusted for age, the duration of infertility, body mass index, and type of infertility and number cleavage stage embryos or blastocysts of embryos transferred using multivariable logistic regression, all of which contributed to the robust results of this study.

At the same time, this study still had its limitations. As with other relevant clinical studies, an important limitation of this study was the retrospective design, even though we established strict inclusion and exclusion criteria and adjusted confounding factors to control bias through multivariable logistic regression.

In addition, the ultrasound monitoring of endometrial thickness might have some measurement imprecision that occur regardless of how experienced the ultrasonographers may be. There were only 37 patients with an endometrial thickness above the maximum threshold. Which suggests that more HRT-FET cycles especially those with thick endometrium are to be collected in future studies, with the hope of being able to determine an optimal range of endometrial thickness for pregnancy outcomes.

In the future, we will continue analyze the data of our center to evaluate the difference between endometrial thickness on the first progesterone day and that on the ET day, and its correlation with the pregnancy outcomes, so as to provide guidance for clinical practice. In conclusion, in the HRT-FET cycles, a satisfactory live birth rate can be obtained when endometrial thickness is kept within the range of 8.

If the endometrial thickness is too thin or too thick, the live birth rate will be reduced. Based on these research results, It is recommended to medical practitioners that transferring embryos should be conducted when the endometrial thickness reaches 8.

The risk of preterm labor and neonatal birth weight were not significantly correlated with endometrial thickness. Browse Subject Areas? Click through the PLOS taxonomy to find articles in your field. Abstract Objective To investigate the impact of endometrial thickness on the embryo transfer ET day on the clinical pregnancy outcomes of frozen-thawed embryo transfer cycles which have undergone hormone replacement therapy HRT-FET. Results After adjusting for the age, duration of infertility, body mass index BMI , infertility type and number and type of embryos transferred, a significant correlation was observed to be between the endometrial thickness and implantation rates aOR: 1.

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Wendy Burch is an Emmy-winning journalist, acclaimed professional writer, and inspiring motivational speaker. Some causes include: Estrogen deficiency Poor blood flow to the uterus Uterine fibroids Adhesions or scar tissue in the uterus, caused by trauma or infection Hydrosalpinx Chronic endometritis infection of the endometrial cells If your doctor determines that there is a specific anatomical issue that could be contributing to a thin endometrium, they may recommend treating the problem before trying to get pregnant.

Take estrogen supplements. Focus on blood flow. Partake in regular, moderate exercise. Most of us have relatively sedentary lives these days, with desk jobs which keep us sitting for hours. During that time, blood flow slows and the reproductive organs are compressed. If you are trying to improve your uterine lining, moving your body is very important. When you raise your heart rate you multiply the number of times that fresh, oxygenated blood flows through your body. Eliminate or limit substances which may restrict blood flow.

Caffeine and nicotine are not good for your circulation: you should quit smoking and cut back coffee to one cup a day. Certain seasonal allergy medications and cold remedies which are designed to stop nasal swelling can also constrict your veins.

Check with your doctor about which over the counter remedies you should avoid at this time. Look into acupuncture. Many women find that a course of acupuncture is helpful at this stage of treatment. Researchers are still investigating the effects of acupuncture on fertility, but there are some studies that suggest it can improve circulation. Ask your fertility doctor about Viagra suppositories. While Viagra is usually used to improve blood flow to the penis in cases of erectile dysfunction, it can also be used to encourage blood flow to the female pelvic region through the use of vaginal suppositories.

Consider your body weight.