Definition
The term “pregnancy hormone” primarily refers to human chorionic gonadotropin, HCG or beta-HCG for short. This peptide hormone is produced by part of the placenta and is an important pregnancy-maintaining hormone. In addition, beta-HCG is the hormone measured in standard pregnancy tests. Other important pregnancy hormones are estrogen and progesterone. Pregnancy hormones are those hormones which are responsible for the course and maintenance of the pregnancy.
What are they?
There are hormones that are considered pregnancy hormones in the narrower sense, as well as hormones that are often only included in a broader sense. In the following section you will find an overview of important pregnancy hormones and their rough function:
- Human Chorionic Gonadotropin: This hormone is produced by part of the placenta. It is measured in the commercially available pregnancy tests to detect pregnancy.
- Estrogen: Estrogens are produced during pregnancy, especially in the placenta.
In the non-pregnant woman, the ovaries take over this task.
- Progesterone: Progesterone belongs to the progestins and is produced by the placenta during pregnancy. It is one of the important pregnancy-maintaining hormones.
- Prostaglandins: Prostaglandins are small tissue hormones that are very important especially at the end of pregnancy. They are produced by almost all tissues.
At the end of pregnancy, however, high concentrations are found in the placenta.
- Oxytocin: Oxytocin is produced in the mother’s brain, more precisely in the hypothalamus. Especially at the end of pregnancy and during the breastfeeding period the importance of oxytocin increases.
- Prolactin: Prolactin is produced in the maternal pituitary gland and also gains importance at the end of pregnancy.
- Thyroid hormones: Thyroid hormones are produced by the mother until the 12th week of pregnancy. Only in the 12th week of pregnancy does the fetus begin to produce its own hormones.
What effect do they have?
Pregnancy hormones fulfil important tasks and are indispensable for the maintenance and smooth progress of pregnancy. In the following section the most important pregnancy hormones and their effects are presented:
- Human Chorionic Gonadotropin: The hormone known as beta-HCG is responsible for maintaining early pregnancy. Beta-HCG reaches its maximum concentration until the 10th week of pregnancy and then decreases continuously.
Other important functions are also known. It promotes germ implantation and organ development, prevents germ rejection and improves blood circulation in the uterus. Furthermore, beta-HCG promotes the development and growth of the umbilical cord.
- Oestrogen: Oestrogens, especially estriol, promote the growth of the mammary gland and cause the muscle wall of the uterus to become thicker.
- Progesterone: Progesterone is one of the most important pregnancy-maintaining hormones.
It helps to maintain the pregnancy and performs many functions, such as closing the cervix. Shortly before birth, progesterone promotes the formation of oxytocin receptors, so that labor activity increases and birth can be initiated.
- Oxytocin: Oxytocin takes over important tasks especially at the end of pregnancy and during the breastfeeding period. It promotes contractions so that the birth can be initiated.
It also promotes the bond between mother and child after birth. Oxytocin also plays an important role in breastfeeding. After birth, it also promotes the regression of the uterus.
- Prolactin: Prolactin is not a “pregnancy hormone” in the narrower sense, as it only becomes active after pregnancy. It promotes milk production and is therefore essential for breastfeeding. In addition, it suppresses ovulation and menstruation so that it protects the woman from another pregnancy during the breastfeeding period.
- Thyroid hormones: Thyroid hormones are particularly important for the neurological development of the child.
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