Hormone changes play a big role in making you feel tired, especially the hormone progesterone. This hormone rises sharply in the first trimester. In addition, as blood volume increases to supply the developing placenta and fetal circulation, your heart pumps faster and stronger.
It's common to feel tired, or even exhausted, during pregnancy, especially in the first 12 weeks. Hormonal changes at this time can make you feel tired, nauseous and emotional. The only answer is to rest as much as possible.
Fatigue is most common in the first 12 weeks of pregnancy because this is when your body changes and starts adapting to the development phases of an embryo. This is when the placenta, the main source of life-support for your baby, is growing.
Pregnant women carrying girls have a greater chance of experiencing nausea and fatigue, according to the results of a study from the USA's Ohio State University Wexner Medical Center.
Although experience with fatigue tends to vary, most women will feel more tired than usual during their pregnancy. Fatigue during pregnancy is most common during the first trimester. It tends to go away during the second trimester, but will usually return in the third trimester.
What pregnancy trimester is the hardest? For many women, the first trimester of pregnancy is often the hardest. During this period, your body is going through a major transformation and needs time to adjust to the changes.
Zanotti reassures expectant mothers not to stress if they accidentally find themselves on their backs for a brief spell. “We do know that short periods of time ― even if you were on your back for an hour or two ― probably do no harm to your child,” she says.
Your nausea and vomiting may be worse than ever: Morning sickness peaks around 9 or 10 weeks of pregnancy for many women. That's when levels of the pregnancy hormone human chorionic gonadotropin (hCG) are highest (morning sickness is thought to be linked to rises in hCG and estrogen).
Even a week of feeling more tired than usual is not uncommon. Yet most people can tell when their fatigue feels like something more serious. If that's the case, or your fatigue gets worse or lasts longer than a week or two, it's time to see your doctor.
Pregnancy-Safe Alternatives
Back sleeping is no longer safe after 28 weeks gestation, but there are a few other comfortable positions for you to safely doze in.
First Trimester (0 to 13 Weeks)
Most miscarriages and birth defects occur during this period. Your body also undergoes major changes during the first trimester.
Most miscarriages - 8 out of 10 (80 percent) - 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.
Pregnancy lasts for about 280 days or 40 weeks. A preterm or premature baby is delivered before 37 weeks of your pregnancy. Extremely preterm infants are born 23 through 28 weeks. Moderately preterm infants are born between 29 and 33 weeks.
In most cases, there's a reason for the fatigue. It might be allergic rhinitis, anemia, depression, fibromyalgia, chronic kidney disease, liver disease, lung disease (COPD), a bacterial or viral infection, or some other health condition.
During the first trimester, it is safe for a woman to sleep in whatever position she feels comfortable in, whether this is on her back, side, or stomach. Any combination of the above positions is also fine. The uterus has not grown large enough to interfere with sleep.
Boys' and girls' genitals develop along the same path with no outward sign of gender until about nine weeks. It's at that point that the genital tubercle begins to develop into a penis or clitoris. However, it's not until 14 or 15 weeks that you can clearly begin to see the differentiated genitalia.
It's all about Dad's genes
A man's X and a woman's X combine to become a girl, and a man's Y combines with a woman's X to become a boy. But if the sperm don't have equal Xs and Ys, or if other genetic factors are at play, it can affect the sex ratio.
Which parent genetically determines the gender (sex) of a baby? Neither parent is fully responsible for determining the sex of the baby. However, all eggs produced by the female have an X sex chromosome, and all sperm from the male have either an X or Y chromosome.
The age where a man is most fertile is between 22 and 25 years. It is suggested to have children before the age of 35. After this age, the male fertility begins to worsen. After 35, the sperm might result in pregnancies where mutations can occur.
Male fetuses are more fragile and are statistically less likely to be conceived or survive pregnancy when food is in short supply. Female sperm are more robust and baby girls are hardier early in pregnancy, so in leaner times they may be more able to survive.