Pregnancy

The beginning of pregnancy

Every woman is born with a supply of egg cells (or ova) in her body. These are being formed while she is still an unborn child in her mother's womb. A female fetus as young as 20 weeks is already carrying around six million egg cells. As the pregnancy progresses, the number decreases until it is just about one million at birth. Even after birth, the number of egg cells continues to decline. Then, when the woman enters her fertile years, she "only" has about 180,000 eggs remaining.

For for men, under normal circumstances, the amount of sperm cells at an average ejaculation is immense.

With the fusion of the woman's egg and the man's sperm cell, the foundation for pregnancy is laid. Yet pregnancy is not assured at that point. More than half of fertilizations are lost without being noticed.

Different stages of pregnancy

Conception:

Immediately after fertilization, where the DNA of the father and the mother come together, we speak of a zygote. That single cell with genes from both parents is the basis of a new individual. The zygote travels through the fallopian tube and arrives in the uterus after about 3 to 5 days.

The cell of the zygote divides continuously and eventually forms a cluster of dividing cells called the blastocyst. Only when this blastocyst settles into the endometrium (uterine wall) has pregnancy begun.

The embryonic phase:

This phase begins with the 3rd week of pregnancy and ends in the 9th week. During this phase, organ systems are laid out and cells begin to specialize and differentiate.

The fetal phase:

In the 9th week there is a miniature human being with all the trimmings. This phase lasts until birth. During this phase, strong growth and maturation take place. Between the 16th and 18th week, the mother begins to feel certain movements of the fetus.

The corpus luteum

At ovulation, the egg jumps out of its follicle. A follicle is a vesicle in which the egg can mature. After ovulation, the empty follicle forms into corpus luteum, or yellow body. The yellow body produces progesterone, which further prepares the endometrium (endometrium) for the implantation of a fertilized egg and keeping the pregnancy on track.

Below, we will focus a little deeper on pregnancy hormones.

Placenta

The formation of the placenta (placenta) begins early in pregnancy. In the placenta there is an exchange of nutrients, antibodies and oxygen from the mother to the embryo and waste products back to the mother. The placenta separates the mother's bloodstream from the embryo's bloodstream because there should be no direct contact between the mother's bloodstream and the child. Also, the placenta takes over hormone production from the corpus luteum.

Pregnancy hormones

Pregnancy is maintained for 40 weeks by means of a changing hormonal environment.

LH:

Luteinizing hormone (LH) allows a fertilized egg cell to settle in the uterus. After this, HCG takes over the function of LH.

HCG:

From the implantation of the egg, an important pregnancy hormone is produced: HCG (human chorionic gonadotropin). This hormone ensures the maintenance of pregnancy and further development of the embryo. HCG also prevents the maturation of new eggs. Pregnancy tests measure the presence of this hormone. During pregnancy, the HCG hormone causes the senses to function better. Smell, in particular, is improved. This has the function of making a pregnant woman less likely to ingest foods that are not good.

Progesterone:

Progesterone is an important hormone during pregnancy and has several functions. During pregnancy, progesterone levels continue to rise. Adequate levels of progesterone are essential for keeping the pregnancy instantaneous. It is involved in the growth and blood flow of the endometrium so that the fertilized egg can implant.

It suppresses contractions of the uterus preventing premature birth. And it prevents ovulation during pregnancy. Also, it helps prepare the breasts for breastfeeding. For the mother, it provides support for thyroid function so that body temperature is raised slightly. Furthermore, it has a calming effect and helps improve mood.

Oestrogen:

Oestrogen helps with the development of your baby's organs and the proper functioning of the placenta. Later in pregnancy, estrogen helps prepare your body for breastfeeding. It can also cause nausea during pregnancy.

HPL:

This hormone, in full Human Placental Lactogen, is made by the placenta. It provides nutrition to the fetus. It also stimulates the mammary glands in the breasts for breastfeeding. Together with progesterone and HCG, it keeps the embryo from being rejected.

Prolactine:

Breast gland tissue is stimulated by the production of the hormone prolactin. This prepares the body for breastfeeding and stimulates milk production after childbirth.

Supplements and pregnancy

It is obvious that a lot is asked of a woman's body during and around pregnancy. Therefore, it is important that her condition remains good. Also, the unborn child depends on what the mother takes in for nutrients and building blocks. Therefore, things like nutrition, lifestyle and adequate sleep are crucial. Unfortunately, it is not always possible to create the most optimal conditions.

Pregnancy sickness, for example, can negatively affect nutrient status. There are nutritional supplements specifically formulated to provide support during this period. In fact, the Basic Prenatal is Thorne's best-selling product in the United States. Furthermore, the Dutch Nutrition Center (Voedingscentrum) points out the importance of getting enough vitamin D, iodine, calcium, iron and omega-3 during pregnancy.

With regard to iodine, the RIVM began a study in early 2023 to determine the amount of iodine in the bodies of pregnant women and whether it is sufficient. Indeed, the UMCG reported in late August 2022 that it has been found that we are getting less and less iodine through our diet. Iodine is important for the neurological development of the fetus.

The importance of folic acid

Already before conception, sufficient folic acid is important and also during pregnancy. The neural tube is formed early in pregnancy and from this the spinal cord is then developed. During pregnancy, folic acid is involved in the closure of the neural tube.

Folic acid is also important for the formation of the placenta and for the growth of the unborn child. Folic acid plays a major role in cell division processes. With enough folic acid, there is a reduced risk of neural tube defects, spina bifida.

Omega-3 fatty acids during pregnancy?

Omega-3 fatty acidsconsist of EPA and DHA. Particularly important during pregnancy is the fatty acid DHA, which is good for the brain and vision. There are special omega-3 fatty acid supplements for pregnant women on the market. These contain a higher dose of DHA.

Written by: Liesbeth Thoen and Marcella van der Wel

Updated November 18, 2024