What Hormones are Essential for Your Surrogacy Pregnancy?

Hormones play a vital role in a surrogacy pregnancy. But, have you ever wondered how they work?

In a natural pregnancy, your body produces hormones required to prepare the reproductive organ for conception. These hormones are essential for maintaining a healthy pregnancy so that the embryo can grow and develop. But in gestational surrogacy, a Surrogate’s body is prepared to carry the pregnancy through hormone supplements and medications.

Gestational surrogacy involves a process known as in-vitro fertilization. First, eggs are harvested from the Intended Parent or an egg donor. The eggs are fertilized in the laboratory and the resulting embryo(s) are then placed in the uterus of the Gestational Surrogate. Surrogacy benefits the Surrogate Mother in many ways, but it is also demanding.

Surrogate Mothers need medications in order to:

  1. Synchronize the menstrual cycle with the egg donor, so that the Surrogate’s uterus is ready for successful embryo transfer.
  2. Ready the Surrogate’s uterus for pregnancy by administering two essential hormones, progesterone and estrogen. These two hormones reproduce Surrogate’s natural cycle in order to increase the chances of pregnancy and prevent miscarriage.

As we see why the hormones are necessary for surrogacy pregnancy, let us learn how the major hormones work:

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Hormones That Play Important role During Surrogacy Pregnancy

Human Chorionic Gonadotropin

Human chorionic gonadotropin (or hCG) is the hormone that pregnancy tests detect in your pee or blood for a positive result. It is produced in the placenta after implantation.

HCG is essential for the development of the “corpus luteum” – an endocrine structure formed in the ovaries during the early months of pregnancy. This structure is responsible for the production of estrogen and progesterone in early pregnancy.

HCG reaches its peak by the eleventh week at the latest.


Estrogen is one of the most important hormones for pregnancy and one you have probably heard about. This hormone acts in a cyclical pattern, going up before ovulation and down after.

Estrogen also produces a wide range of feel-good hormones, such as endorphins and serotonin. Hence, its decline every month before your menstruation may be responsible for the difficult emotions a lot of women experience in the week preceding their period.

The levels of estrogen consistently go up before peaking a few weeks to labor. The estrogen hormone is initially produced by the corpus luteum before the placenta takes over its production.

There are three types of estrogen:

  • Estrone (E1)

The female body produces estrone (E1) after menopause. Although it’s a weaker form of estrogen, it can be converted to the other two types of the hormone if need be. This takes us to

  • Estradiol (E2)

Estradiol is the commonest type of estrogen produced in the female body during adulthood.

Extremely high levels of estradiol, especially if it’s too high compared to progesterone, can lead to various symptoms. For example, you may experience acne, painful menstruations, sore breasts, loss of libido, a reduction in bone density (osteoporosis), etc.

  • Estriol (E3)

Estriol is the most notable type of estrogen during pregnancy. It helps women develop their womb lining and increases over the course of the pregnancy.

The levels of this hormone peak just before childbirth and rapidly decrease after.


Progesterone is a popular hormone that plays a key role throughout a woman’s lifetime. But unlike estrogen, the levels of progesterone increase after ovulation and quickly decrease before the monthly period if the woman is not pregnant.

However, if the woman is pregnant, progesterone levels will keep increasing throughout the pregnancy. This is because the hormone’s primary role is to develop the womb lining in preparation for pregnancy.

Progesterone makes the womb receptive by stimulating it to generate the nutrients needed to support the embryo.

Aside from being an important player in developing the lining of the womb, progesterone also stops the womb from contracting and inducing premature labor. This is why progesterone hormone may be recommended for you in the early days of your surrogacy journey. Progesterone is typically administered vaginally in the form vaginal cream or insert. Most of this hormone is initially secreted by the corpus luteum during pregnancy before the placenta takes over its production.

Even though estrogen energizes the body, progesterone is relaxing. That’s why decreasing progesterone can cause anxiety during premenstrual syndrome and the postpartum stages.


Other than helping with the development of the growing baby, prolactin also plays a crucial role in the production of breastmilk. It is one of those hormones that cause vaginal dryness, sore breasts, and other symptoms after childbirth.

Usually, non-pregnant women have a low amount of prolactin, and increased levels can result in infertility.


Relaxin stops the womb from contracting, especially in the early weeks of pregnancy. Aside from this important role, it also helps a woman’s body relax for labor.

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As one can deduce, these hormones perform different roles at different times during a pregnancy. And knowing these changes and the possible side effects that may accompany them can help you feel in control of your body.

The first twelve weeks of pregnancy are known for fatigue, morning sickness, tender breasts, constipation, new cravings, headaches, increased urination, and weight fluctuations. It’s no surprise that most of these symptoms in the early days of pregnancy are caused by rapidly changing hormones. Your body is having an unusually high level of estrogen, HCG, relaxin, and progesterone, and these changes won’t happen without causing changes in your body.

Symptoms you may develop during the first trimster of surrogacy pregnancy and the hormones responsible for them

Morning sickness

There are different evidences as to what actually causes morning sickness. However, it is largely believed that human chorionic gonadotropin (hCG) plays a key role.

Aside from speeding up the development of the corpus luteum, hCG also enhances your sense of smell. This may result in food aversions that you didn’t have previously, and in most cases, vomiting and nausea.


As mentioned earlier, both relaxin and progesterone help calm the muscles, stopping it from contracting and preventing premature labor. Sadly, that is not limited to the womb alone. It affects your gastrointestinal tract too. A more relaxed digestive system means less constipation.


Due to decreasing hCG levels, a lot of the first trimester’s worrying symptoms stop or subside in the second trimester (weeks 13 to 28). However, this pregnancy stage also comes with its own set of symptoms, including

  • body aches
  • swelling of the face and lower extremities
  • sinus issues
  • darkening of the skin surrounding the nipples and other parts of the body

Still, hormones are the causes of these symptoms. In the 2nd trimester, hormones such as progesterone, prolactin, and estrogen continue to increase, whereas hCG decreases once the corpus luteum is formed.

Like in the first trimester, hormone fluctuations can bring about certain changes in the second trimester

Changes in skin pigmentation

This is also referred to as melasma or the mask of pregnancy, and it’s mainly due to hormones. The hormone fluctuations during the second trimester can result in the proliferation of pigment-producing skin cells.

Pregnant women will notice more dark skin patches, especially after exposing themselves to the sun.

There’s no need to be worried, though, if you are experiencing melasma. It poses no harm and naturally goes away after childbirth for most women. A lot of women also have melasma as an adverse effect of hormonal birth control.

Sinus problem

If you’re not trying to become pregnant for the first time, you have probably experienced an increase in nasal blockage or even nosebleeds entering the 2nd trimester. Hormones are also the cause of this.

As progesterone and estrogen keep increasing throughout this stage, they significantly impact the mucous membranes of the nose.

Increased hair and nail growth

One pregnancy symptom that most women like is increased hair and nail growth. A lot of women begin to notice enhanced nail growth and a fuller, thicker head of hair around week 20 of pregnancy.

This is caused by your ever-increasing estrogen, which promotes the growth of hair and nails. Enhanced blood circulation during pregnancy also contributes. However, you need to note that these are for the short term. We will talk more about that below.

In the last trimester, your body will have already reached its highest levels of prolactin, progesterone, and estrogen in preparation for labor. Increased progesterone and estrogen can result in positive emotions and happy moods. However, some common symptoms women experience during this phase include

  • mood swings
  • insomnia
  • hemorrhoids
  • heartburn
  • sore breasts
  • increased swelling
  • contractions
  • shortness of breath etc.

Symptoms that are noticeable in the third trimester and hormones responsible for them

Water retention

As said earlier, estrogen will have risen to its highest levels in the third trimester. Elevated estrogen levels come with swelling, and this is the reason your face, hands, and ankles may feel puffy.

Heartburn or acid reflux

Discomfort after meals is not only due to your baby becoming bigger and bigger every day. Just like how progesterone can calm your gastrointestinal tract in the 1st trimester and cause constipation, it can relax your esophagus too. This allows more liquid and foods to journey back up – which eventually results in heartburn.

Sore, tender breasts

This is one symptom you may experience all through the pregnancy. However, for a lot of women, it reaches its peak during the last trimester of pregnancy.

The reason is that our bodies have sped up the production of prolactin in preparation for breastfeeding. Plus, your breasts may start leaking a bit at this time, which is completely natural.

Postpartum Changes

Postpartum transition is a serious matter! Unlike when it’s your own pregnancy, you will be passing through postpartum without needing to cater to a baby. And this will allow you more time to focus on your own health and well-being.

The levels of estrogen and progesterone, which have been continuously increasing during the whole pregnancy, drop rapidly following childbirth. However, prolactin will remain at its peak.

These hormone fluctuations can result in various emotional and physical changes, such as:

Menopause-like symptoms

A lot of women experience menopause-like symptoms, such as vaginal dryness, after the birth of the baby. This is natural and caused by the production of prolactin in the body, which makes it difficult for the vagina to lubricate itself.

Baby blues & postpartum depression

Our levels of estrogen and progesterone, which have been on the high side throughout the whole pregnancy, go down after childbirth.

This can lead to a lot of things, from temporary baby blues to more severe postpartum depression. While certain levels of feeling down and mood swings are normal post-delivery, you need to consult with a qualified medical practitioner if you think that it’s affecting your everyday life and exceeding the normal highs and lows.

Hair loss

While an increase in hair thickness is a sign of pregnancy, hair loss is one of the common side effects of postpartum.

After giving birth to a child, you lose your placenta – the organ that had been producing most of your estrogen during your pregnancy. Without your placenta, the production of estrogen rapidly reduces, and your hair is no longer induced to stay in the actively growing phase. Consequently, you go through a period of rapid hair loss, but don’t worry.

The manes of most women will go back to their thickness before the pregnancy.

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How do you alleviate symptoms of hormonal fluctuations

For a lot of women, minor lifestyle changes can help improve the symptoms of hormone fluctuations during surrogacy pregnancy and post-delivery.

Regardless of how good your lifestyle is, your hormones will be undergoing big changes during pregnancy, and pregnancy symptoms are unavoidable. However, there are some steps you may take to help your body navigate this journey.


Sure, nutrition is important for the healthy development of the growing baby, but it does not end there. The foods we take are key to balancing our hormones.

Generally, it’s best to follow an anti-inflammatory diet when pregnant as it will help the other parts of your body to continue to function alongside your fluctuating hormones. Although this varies from one person to another, eating more veggies, proteins, and “good” fats is good for balanced, happy hormones.


The human body is made to support a wide range of movements, but not all exercises are the same. Like diet type, some women may be okay with running or cycling, whereas others do just fine with yoga and Pilates.

Although you should beware of reducing the intensity of your workouts when pregnant, movement is still essential for a healthy pregnancy.

Once you have been cleared to exercise after childbirth, you can promote accelerated hormone balance by managing stress and regulating your blood sugar. Hence, it’s crucial not to exercise too much, as this can result in chronic stress response and increased cortisol levels.

Stress management

Cortisol is a steroid hormone secreted by the adrenal gland that initiates our “fight-or-flight” response.

While a little cortisol is good for the body, today’s fast-paced society has left the bodies of many people over-filled with chronically-high levels of cortisol, which eventually causes problems to our adrenals.

High levels of cortisol can also result in increased androgens and other hormone imbalances, hence increasing the risk for embryo transfer and pregnancy issues.


A lot of makeup products and home cleaners have harmful chemicals known as endocrine disruptors. These chemicals can disrupt your internal balance and cause harm to a growing baby.

You need to consider replacing these harmful products with safer ones. Doing so will not only be beneficial for you but also for the baby in your womb.

Remember that it’s important to consult with a qualified medical practitioner before changing your diet or exercise routine, especially when you are pregnant.


Being pregnant with another person’s child can cause a lot of changes in your physical and emotional aspect, and that includes your hormones.

Prolactin, estrogen, hCG, progesterone, and other hormones play a key role in preparing your body for a healthy pregnancy and childbirth. However, these changes do come with their side effects.

Hence, as you are becoming a Gestational Surrogate, it’s important to know why you are having certain symptoms and to create a plan to prepare your body for a safe, successful pregnancy.

If you are planning to become a Surrogate Mother, fill out an application first to see if you meet the qualification criteria. If have any questions about gestational surrogacy and the changes that can occur to your body during a surrogacy pregnancy, please visit our website where we can answer your queries in chat.

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Physician’s Surrogacy is the nation’s only physician-managed surrogacy agency. Join our community to get updates on surrogacy, expert insights, free resources and more.