Relaxin Hormone During Pregnancy- Everything You Need To Know

However, during pregnancy, the quantity produced in the ovary cannot meet the demand of this hormone so the placenta and the lining of the uterus also start producing this hormone. In both pregnant and non-pregnant women relaxin hormone rises to its highest within 14 days of ovulation, and then declines in the absence of pregnancy, resulting in menstruation. During pregnancy, the levels of relaxin hormone considerably rise and pregnant women have 10 times the normal amount of relaxin hormone in their bodies.

Role Of Relaxin Hormone During Pregnancy

Actually, the role of the relaxin hormone in pregnancy starts way before conception. The relaxin hormone plays an important role during pregnancy in the following ways:

Preparing The Uterus For Pregnancy

The levels of relaxin increase after ovulation. At this time, in order to prepare the uterus for possible pregnancy, the hormone-

• Prepares the uterine lining to facilitate implantation
• Relaxes the uterine wall to prevent contractions, which can hinder the implantation of a fertilized egg
• However, if fertilization does not take place, the relaxin levels drop to normal.

The Role Of Relaxin During The First Trimester Of Pregnancy

During the early weeks of pregnancy, the relaxin levels are higher and this helps in the successful implantation of the fertilized egg into the uterine wall.

Relaxing Intrauterine Membrane

During pregnancy, the relaxin hormone prevents the possible contractions of the intrauterine membrane. In this way, it helps in sustaining a pregnancy and avoiding premature childbirth.

Relaxin Hormone Helps Relaxes Arteries

The blood volume doubles in women during pregnancy in order to meet the increased demand for oxygen and nutrients for the fetus as well as the mother. The relaxin hormone relaxes the blood vessels to handle the increased blood volume. This way, the relaxin hormone prevents the possibility of high blood pressure.

Helping With Parturition

Parturition refers to the process of delivering a baby and placenta through the vagina. During the last trimester, relaxin prompts the rupture of the membranes surrounding the fetus. It also stimulates the growth, opening, and softening of the cervix and vagina and aids the process of childbirth. Relaxin hormone also relaxes the ligaments at the front of the pelvis to minimize the effort of delivery.

Helping With Mammary Gland Development

During the second half of pregnancy, the relaxin hormone helps with the development of the mammary gland making it ready for the upcoming lactation period.

Stretching Of Abdominal Muscle And Rib Cage

 In the course of pregnancy, the abdominal muscles are stretched to accommodate the growing uterus. The rib cage is also stretched to balance the pressure applied by the growing uterus on the diaphragm. Both of these are possible due to the increased level of the relaxin hormone.

How Does The Relaxin Hormone Make Joints Unstable During Pregnancy?

Collagen is the main part of the connective tissue in ligaments, cartilages, and tendons. The ligament which is made up of this connective tissue, determines the stability of the joints. The relaxin hormone increases the water content of the collagen fiber, which is the main part of connective tissue. This results in increasing the elasticity of the ligament. Thus, when the otherwise inelastic ligament becomes more flexible than normal, the joints tend to lose their stability.

Side Effects Of Relaxin Hormone During Pregnancy

The same qualities of the relaxin hormone that helps with pregnancy, delivery, and lactation have a flip side too. Some of the side effects of relaxin hormone during pregnancy are:

• Back pain: The relaxing property of the hormone relaxin affects the ligaments of the spine. During pregnancy, just like other ligaments in the body, the ligament of the spine also becomes more elastic and less stable. This makes the expecting mother more susceptible to the back pain
• Pelvic Girdle Pain: The relaxin hormone often tampers with the pelvic girdle structure which is made up of a lot of joints of legs, hips, etc. As a result, all the ligaments in the joints become more elastic and lose stability. This can often cause pelvic girdle pain during pregnancy
• Increased risk of injury: During pregnancy, especially during the last trimester, the overly stretched muscle (because of the act of relaxin hormone) increases the chance of injury in pregnant women as they become more wobbly and unsteady due to the increased levels of relaxin hormone

Although the relaxin hormone has its side effects, this hormone is important to make the birth process easier. So, pregnant women should take extra care of their posture during pregnancy, especially during the first and the third trimesters, when the relaxin hormone is at its peak in the body.

FAQs

1. Why Does Relaxin Hormone Cause Pain?

Relaxin has been observed to induce the relaxation of ligaments across various anatomical regions, thereby rendering pregnant women less stable and more susceptible to injuries, particularly in their lumbar regions. Relaxin hormones induce muscle relaxation and promote ligament and joint laxity, particularly in the pelvic region, resulting in pelvic girdle pain.

2. Does Relaxin Cause Labor?

Relaxin hormone is detected during weeks 7-10 of pregnancy and is generated throughout the pregnancy. The conclusion of pregnancy causes your body to produce more relaxin.

3. Does Relaxin Cause Back Pain?

Relaxin facilitates the relaxation of muscles, joints, and ligaments in the pelvic region, thereby aiding in the facilitation of labour and delivery.