The heart

First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst. Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an embryo attached to a placenta and surrounded by fluid-filled membranes.

In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilization, or outside in the case of external fertilization.

From Wikipedia, the free encyclopedia. Mammalian embryogenesis is the process of cell division and cellular differentiation during early prenatal development which leads to the development of a mammalian embryo.

Just four weeks after conception, the neural tube along your baby’s back is closing. The baby’s brain and spinal cord will develop from the neural tube. The heart and other organs also are starting to form and the heart begins to beat. Structures necessary to the formation of the eyes and ears develop.

Your baby’s gender is determined at the moment of conception – when the sperm contributed a Y chromosome, which creates a boy, or an X chromosome, which creates a girl. Boys’ and girls’ genitals develop along the same path with no outward sign of gender until about nine weeks.

Baby’s sex organs develop mostly between weeks 7 and 12 Between week 7 and week 12 of pregnancy, the foundations of your baby’s sex organs develop. At about week 9, a baby boy’s genitals begin the process of becoming male.

A fetal heartbeat may first be detected by a vaginal ultrasound as early as 5 1/2 to 6 weeks after gestation. That’s when a fetal pole, the first visible sign of a developing embryo, can sometimes be seen. But between 6 1/2 to 7 weeks after gestation, a heartbeat can be better assessed.

This is called an anembryonic pregnancy, which is also known as a blighted ovum. Or it may be that your baby started to grow, but then stopped growing and they have no heartbeat. Occasionally it happens beyond the first few weeks, perhaps at eight weeks or 10 weeks, or even further on.

Most miscarriages happen in the first trimester before the 12th week of pregnancy. Miscarriage in the second trimester (between 13 and 19 weeks) happens in 1 to 5 in 100 (1 to 5 percent) pregnancies. As many as half of all pregnancies may end in miscarriage.

Bleeding may start as light spotting, or it could be heavier and appear as a gush of blood. As the cervix dilates to empty, the bleeding becomes heavier. The heaviest bleeding is generally over within three to five hours from the time heavy bleeding begins.

While excessive stress isn’t good for your overall health, there’s no evidence that stress results in miscarriage. About 10 to 20 percent of known pregnancies end in miscarriage. But the actual number is likely higher because many miscarriages occur before the pregnancy is recognized.

High doses of daily caffeine during pregnancy — whether from coffee, tea, caffeinated soda or hot chocolate — cause an increased risk of miscarriage, according a new study by the Kaiser Permanente Division of Research.

Stress can’t cause a miscarriage directly. Chronic stress can affect your pregnancy in other ways, and there is limited evidence to suggest that it may exacerbate some of the main causes of miscarriages.

TUESDAY, Sept. 10, 2019 (HealthDay News) — Pregnant women are often told to sleep on their left side to reduce the risk of stillbirth, but new research suggests they can choose whatever position is most comfortable through most of the pregnancy.

It’s a boy if:

• You didn’t experience morning sickness in early pregnancy.
• Your baby’s heart rate is less than 140 beats per minute.
• You are carrying the extra weight out front.
• Your belly looks like a basketball.
• Your areolas have darkened considerably.
• You are carrying low.
• You are craving salty or sour foods.

Sleep studies tell us that hormonal changes, plus the discomforts of later pregnancy, can break up a pregnant woman’s sleep cycle. The first trimester can bring insomnia and night waking. Most women feel the need to take naps to battle daytime sleepiness and fatigue.

Physical demands (lifting, standing, bending) Heavy lifting, standing for long periods of time, or bending a lot during pregnancy could increase your chances of miscarriage, preterm birth, or injury during pregnancy.

Missionary position (with mom on bottom) isn’t a good idea as it compresses blood flow to mom and baby, particularly after the 20th week. Some find prone positions (lying flat on the stomach) uncomfortable. Also, as noted by every doctor and pregnancy book you’ll ever read, don’t blow air up there.

This means that semen from the male must be able to attain the ovule in the female’s oviduct. When a woman is pregnant however, a mucus plug is formed in the cervix, blocking the passage of sperm. This mechanism prevents semen from passing through the pregnant uterus, let alone allowing it to reach the oviduct.

Once you’re 20 weeks along, avoid positions that have you lying flat on your back, such as the missionary position. When you lie on your back, the enlarged uterus puts pressure on your aorta, which compromises blood flow to the placenta.

Sleeping on your left side is often referred to as the “ideal” scenario during pregnancy. Positioning yourself on the left side of your body allows for optimal blood flow from the inferior vena cava (IVC).