Embryo Transfer and How to Keep Uterus Warm After IVF

Let Start by Reviewing, What Happens Before Embryo Transfer?

The aim of every assisted reproductive technique (ART) is to obtain a high-quality embryo. To achieve that, the basic steps in a IVF protocol are:

1. Ovarian stimulation: the goal is to make the ovaries release as many matured eggs as possible to increase your chances of getting pregnant. So, you have to self-administer(with your doctor’s management, obviously!) fertility drugs.
2. Ovum pick-up: On the day of the treatment, an ambulatory procedure will be performed under mild sedation in the fertility center under your doctor’s supervision. Oocytes (as embryologists call eggs in the lab) will be retrieved using a needle guide by ultrasound visualization to reach the ovaries.
3. Fertilization in the lab: once in the lab, where the environment is almost the same as the inside of our body, the embryologist team analyzes the gametes -the eggs and the sperm sample. After sperm fertilizes the egg, the “embryo team” follows up the embryo development, generally for 5 to 6 days, until the transfer. 
4. Embryo transfer: The goal of every clinic is to transfer one high-quality embryo (mainly to avoid multiple births). Embryo transfer is a simple and safe technique, simultaneously performed with an ultrasound to follow the process. But, before that, your doctor must inform you of the number and quality of the embryos obtained. 

So… What happens next?

From the moment you start this IVF journey, it’s important to be leading a healthy lifestyle. This means a balanced diet, quitting smoking and alcoholic drinks, and doing regular physical activities. Also, it can be valuable to start incorporating mindfulness or yoga to control stress and anxiety.

Once you complete the oocyte retrieval procedure, you will be free to go home and continue your (healthy) lifestyle. And 5-6 days later, the blastocyst will be ready to be transferred to your uterus. The procedure is simple and does not require sedation or anesthesia.

AFter about 9 days, the pregnancy could be detected with a blood test.

What is Safe to Do After Embryo Transfer?

Once you leave the fertility center after your embryo transfer, you can continue with your life!

However, this exciting journey has just begun, so you are likely to have many emotions, so the best you can do is take it easy.

The two most important things to avoid:

1. DO NOT participate in strenuous exercise for a few days
2. High stress situations

It is not necessary to stay in bed but keep in mind that after all the steps you have taken to get to this place, with emotions high while waiting for the pregnancy test, the best you can do is take it easy.

Is There Something That I Can Do to Increase IVF Success After Embryo Transfer?

Besides healthy behaviors, anything you can do to help you stay calm and peaceful will increase the chances of a successful embryo implantation. 

• Can I drink or eat anything? As we talked previously, a balanced diet, like the Mediterranean, is the principal recommendation. Rich in vegetables, fruits, whole grains, and olive oils, in addition to low meat consumption, this type of diet provides vitamins, nutrients, and ’’healthy fats” that help hormone production, blood sugar control, and embryo development. You should also avoid caffeine and alcohol.

• Should I take medications? Whether it be supplements (such as folic acid) or hormones (such as progesterone) keep on your medications. It will help to maintain the early stages of pregnancy. If you take other drugs (such as antidepressants) talk to your doctor and follow their orders.

• What about exercise? You can practise low-impact activities, such as yoga, and walking (unless your doctor specifies the contrary). Avoid extreme or high-demand exercises, CrossFit, bootcamps, heavy lifting are not a good idea for now! As well as you should avoid extreme temperatures, like extreme hot (ie. hot yoga) or cold. An interesting prospective study showed that, before IVF treatment, an active lifestyle has a positive impact on IVF outcomes. After embryo transfer, patients have light physical activity or sedentary behavior, so it is difficult to know how much exercise is too much. Although, you have to avoid overstressing your body.

• Should I stay in bed a few days after? There is a lot of controversy here. There is no scientific report that shows post-transfer bed rest improved IVF outcomes. On the contrary, light physical activity improves blood pressure, body oxygenation, and hormone regulation. In addition, it relieves stress and anxiety. 

• And what about sex? This is another point where we don’t have a clear answer. The main risk of sex after embryo transfer is uterine contractions. I want to stop here and talk about progesterone for a minute: the natural function of this hormone in the early stage of pregnancy is to calm the uterus contractions and facilitate embryo implantation. That is why sometimes, doctors recommend taking progesterone when trying to get pregnant.
  • A prospective study with 125 women showed that those who had intercourse during the implantation window -between embryo transfer and the pregnancy test- had a 59% risk of miscarriage. The opposite happens when women have sex the day before the embryo transfer: implantation rates increase. However, more extensive studies must be conducted to establish the risks and benefits of having sex before or after embryo transfer. 

How Can I Increase Blood Flow to Uterus After Embryo Transfer?

Well… Some tips that we have talked about increase blood flow to your uterus, and your whole body. Light exercise and relaxation, a healthy diet and staying hydrated, and alternative techniques, like acupuncture, are also some ways to increase blood flow.

With limitations, some studies show an association between the uterus’s blood flow and implantation rates. Even more, a 2023 study shows that blood flow in the uterine artery is a useful parameter to assess endometrial receptivity -the capacity of the uterus to receive an embryo- and pregnancy outcomes.

What Are the Benefits of Keeping Uterus Warm After IVF Transfer?

This question is a knot of information and myths. To start unraveling this, first, we must know the huge difference between keeping warm and overheating your womb (and your body, in general). During menstruation, warming your womb helps to attenuate cramps by increasing blood flow, as we discussed ways to increase success of embryo implantation. But, overheating increases vessel dilation, the blood runs faster, and nutrients and oxygen do not reach the tissues. 

A wide myth regarding the “cold” uterus, which is a uterus with poor blood flow, in Chinese medicine suggest this may cause infertility. Some women wear warm socks during the IVF procedure with the belief the heat does not leave the body. Others take herb infusions or practice acupuncture before the procedure. Even if these things cannot hurt, they do not affect the IVF outcome. However, a Chinese scientific team evaluated the performance of warm acupuncture on the endometrium (this is inside your body) before the embryo transfer, and observed a clinical pregnancy rate higher than the group that did not received the acupuncture treatment. Despite the small sample (they only performed this in 14 women), they conclude that warm acupuncture may improve the clinical pregnancy rate by raising the local temperature of the lower abdomen, accelerating the blood circulation, improving the uterine environment and endometrial receptivity. 

Final Thoughts

The final step of the IVF treatment is crucial. At this point the quality of the embryo and the status of your uterus must match to give way to implantation. During the 2-weeks waiting for the pregnancy test (the famous beta awaits), anxiety plays a enormeuos role. While you could ask your doctor for some tips to improve your chances, have in mind that avoiding stressful situation will help you to stay calm. Light exercise, mindfulness and a healthy diet are the main choice to increase your chances. Regarding your body temperature, the most important thing to remember, is to keep an average body temperature. And avoid overheating your body, and your womb. Activities like hot yoga, hot baths, or sauna are not recommended. Long hot water immersion increases the risk of infections, as well.

Since 1 in 6 people experience infertility, ARTs have evolved to treat different pathologies. That is why, in 2021, 29% of the women get pregnant through IVF treatment in the UK, while approximately 2.0% of all infants born in the United States every year are conceived using ART.