Week 4 of pregnancy

Some women are already experiencing the first pregnancy symptoms, others may already suspect the little being in their belly, and yet others have no idea yet that they are pregnant. Whether aware or unaware: In the 4th week of pregnancy, significant developments are already taking place in your body. What exactly changes in you and your baby during this week, you can read here.

How big is your baby in week 4 of pregnancy?

Your baby is now up to one millimeter in size, comparable to a poppy seed. It is still so small that during an of your baby, there would still be nothing to see.

4th Trimester: What's Changing for You

The implantation of the fertilized egg is complete, and from now on, it is referred to as the embryo. At this stage, it still consists of two parts: the cells from which the placenta and umbilical cord will later develop ( Trophoblast ) and those from which the actual embryo develops ( Embryoblast ). This week, the amniotic sac, yolk sac, umbilical cord, and Placenta to form. The placental cells fuse with your uterine lining, so that you and your baby are connected via fine blood vessels. However, it is still tiny and at this stage of development Chorion mentioned. To maintain the pregnancy, the placenta now begins to produce various hormones: hCG ( human chorionic gonadotropin ), estrogen and progesterone (corpus luteum hormone). hCG is also referred to as pregnancy hormone and prevents the shedding of the uterine lining. Progesterone relaxes the uterine muscle so that it can adequately expand in the coming months to accommodate your baby. But the rest of the body is also affected by the hormone, so it may be that you now first Pregnancy signs like fatigue, more frequent urination or notice constipation. Some women now feel a slight pulling in the lower abdomen or tense breasts. However, it is just as possible that you are not yet aware of or do not feel the little being in your belly at this time – that is also completely natural. But it won't be long before it makes itself clearly known.

4. WEEKS: Development of Your Baby

The embryo is over the also developing umbilical cord with the Chorion , the precursor of the placenta, connected. This, in turn, now connects via villi with the inner wall of your uterus and your bloodstream, and performs its important function during pregnancy by exchanging oxygen, nutrients, and waste products between your circulation and that of your child. But this is not the only important development that the embryo undergoes this week: until now, all of its cells pluripotent , which means that each cell could develop into any organ. This changes in the fourth week. The cells now begin to specialize and differentiate into three different cell layers, the so-called germ layers,
to further develop. From the outermost cell layer ( Ectoderm ) develop the brain, nerves, hair, nails, skin, eyes, and ears. From the second layer ( Mesoderm ) forms the basis for the skeleton, muscles, heart, and blood vessels. From the innermost layer ( Entoderm ) develop lungs, liver, intestines, and pancreas. It's almost unimaginable that the embryo is only about one millimeter in size!

Questions for your doctor

I have light bleeding – could this be my period?

Even now, it can still be implantation bleeding ( Nidationsblutung ) come. You might notice a light, bright red or brownish bleeding. This occurs when fine blood vessels are injured during implantation – implantation bleeding is therefore no reason to worry. When women are unaware of their pregnancy, it is often mistaken for a period. If you are unsure or experiencing pain, it is best to contact your doctor. You can learn more about this topic in the article „ Bleeding during pregnancy ".

I have drunk alcohol or smoked. Did that harm my baby?

Many women ask themselves this question, especially those who did not expect to be pregnant. In the first weeks of pregnancy, the so-called "all-or-nothing principle" applies. This means that if the embryo is damaged by external influences, it either develops normally or is lost, resulting in an early miscarriage. Only with the development of the organs can the development of the embryo be negatively affected by the consumption of alcohol, nicotine, drugs, or other harmful substances, especially during the critical phase between the 5th and 12th weeks of pregnancy. At the latest, once you find out about your pregnancy, you should immediately abstain from alcohol and cigarettes.

Can I safely determine if I am pregnant?

Maybe you are already feeling some early signs of pregnancy or have a suspicion. However, pregnancy can be reliably confirmed by a blood test only at the earliest at the end of the 4th week or by a urine test from the 5th week of pregnancy. Therefore, a negative pregnancy test does not necessarily mean that you
not pregnant – under certain circumstances, the amount of hCG in your body is simply still too low. Just try again in a few days. Conversely, a positive pregnancy test with near certainty means that you are actually expecting a baby!

Early miscarriage

Your child is still a tiny cluster of cells and very delicate. During this phase of pregnancy, early, often unnoticed miscarriages frequently occur. The embryo now reacts especially sensitively to external influences such as alcohol, nicotine, or medications, and about half of all pregnancies end before the fourth or fifth week. Nevertheless, it is important to know that a miscarriage is not always due to the mother's misconduct. Genetic changes in the embryo that prevent its development, infections, hormonal imbalances, or other causes can also lead to an early miscarriage. In the video "Early Miscarriage," midwife Sissi discusses this sensitive topic and how to handle it.

This is now important

• Alcohol and cigarettes are now off-limits. If you are taking medication, consult your doctor to see if it is still safe to take
  or if there are alternatives.

• Even if you are already suffering from morning sickness and don't have much of an appetite: continue to pay attention to a balanced diet and consume enough folic acid .

• One of the first signs of pregnancy that many women are feeling now is fatigue. Take breaks regularly and avoid stress as much as possible. Although your pregnancy is not yet visible, your body is currently performing at its best

• Pay close attention to special hygiene in the kitchen during this sensitive phase. Some raw foods such as fish, raw milk products, and eggs, but also sprouts and pre-packaged salads, are often contaminated with the so-called Listeria contaminated, which can cause listeriosis. The risk of illness is many times higher for pregnant women. The infectious disease can be transmitted to the unborn child and, in the worst case, lead to a miscarriage. Therefore, make sure to heat foods to at least 70 degrees, wash fruits and vegetables thoroughly, and avoid raw milk products, raw fish, and raw meat. In the article “ Proper Nutrition During Pregnancy “Find a practical list to download, which lists all the foods that now require caution.”

• An infection with toxoplasmosis can also be extremely dangerous for your unborn child. The infectious disease is often transmitted via cats and their feces
  If you are not immune to toxoplasmosis (your doctor can determine this through a blood test), it is better for your partner to clean the litter box in the coming months.

With our pregnancy calendar, we want to accompany you through this exciting time and provide you with relevant information, which also in exchange with our
LILLYDOO experts are being created. Nevertheless, the ones listed here can still
Never replace personal consultation with your doctor or midwife with advice. Always contact your healthcare professional for questions and professional care.