At the 9th week of pregnancy, the baby moves from the embryonic stage to the fetal stage. There is continued rapid growth with huge developmental strides. At 9 weeks, the baby measures about 3/4 of an inch, the size of a peanut.
At this stage, it might be possible to hear your baby's heartbeat for the very first time with the use of a handheld Doppler.
However, this is not always possible and positional changes of the baby may make hearing the heartbeat more of a challenge.
This MNT Knowledge Center feature is part of a series of articles on pregnancy. It provides a summary of each stage of pregnancy, what to expect, and insights into how your baby is developing. Take a look at the other articles in the series:
Symptoms at 9 weeks pregnant
Progesterone relaxes smooth muscle tissue, leading to gas, bloating, burping, and flatulence
At this stage of the pregnancy, there are little, if any, visible physical body changes. However, some physical pregnancy symptoms may already be present, or starting imminently:
- Weight gain
- Nausea and vomiting
- Bloating, gas, constipation
- Food aversions
- Excess saliva
- Frequent urination
- Breast changes/tenderness
(Note: pregnancy increases the risk of urinary tract infections from weeks 6-24; if an individual suspects an infection, a doctor should be contacted.)
Hormones at 9 weeks pregnant
During pregnancy there are variations in certain hormones, these contribute to many of pregnancy's symptoms. Following implantation of the fertilized egg, the body begins to secrete the hormone, human chorionic gonadotrophin (HCG) which is the hormone detected by pregnancy tests. HCG is responsible for regulating estrogen and progesterone and contributes to frequent urination.
Progesterone, which is initially produced by the corpus luteum, rises throughout pregnancy and continues to do so until birth.
In early pregnancy, progesterone is responsible for increasing uterine blood flow, establishing the placenta, and stimulating the growth and nutrient production of the endometrium (lining of the uterus). Additionally, progesterone plays a vital role in fetal development, preventing premature labor and lactation, as well as strengthening the pelvic wall muscles to prepare the body for labor.
In addition to progesterone, the placenta secretes other hormones:
- Human placental lactogen: this hormone is believed to handle mammary gland growth, which is important for lactation following birth. Additionally, it plays a role in increasing nutrient levels in the blood, which is vital to the growth and development of the baby.
- Corticotrophin-releasing hormone: this hormone is not only responsible for determining the length of the pregnancy, but also for the baby's growth and development. Later in pregnancy, the rise in both corticotrophin-releasing hormone and cortisol complete fetal organ development and also provide the mother with a surge of cortisol which has been linked with maternal attentiveness, increasing the mother-baby bond.
Another vital hormone in pregnancy is estrogen, which is responsible for fetal organ development, placental growth and function, and mammary gland growth. Estrogen also helps regulate other hormones produced during pregnancy.
The rise in progesterone and estrogen is also to blame for the mood swings and morning sickness that commonly occur during pregnancy.
Another hormone, relaxin, can cause physical symptoms such as pelvic pain, balance difficulties, and constipation, because of its role in relaxing maternal muscles, ligaments, and joints.
Baby's development at 9 weeks pregnant
At 9 weeks pregnant, the baby has taste buds, and their external ears are fully developed.
At 9 weeks pregnant, developments that are underway include:
- Head/neck: the head is more straightened and rounded
- Eyes: while the eyes remain closed, there is full retinal pigmentation present
- Mouth: the surface of the tongue will now have taste buds and the palate bones start the process of fusion
- Ears: with the external ears fully developed, they appear much more pronounced
- Limbs: all limbs are formed with the fingers and toes having a distinct appearance; the arms are now bent at the elbow
- Abdomen/pelvis: the liver, spleen, and gallbladder form and the intestines continue to make their way into the body from the umbilical cord, and the external genitalia remain unrecognizable
Things to do in week 9 of pregnancy
Week 9 is a good time to schedule a prenatal visit if it has not yet been booked in. Also, if genetic testing is under consideration, this is a good time to speak to a health care provider; testing is generally done between weeks 9 and 12.
Increasing breast size might be causing a certain amount of discomfort. This can be a good time for the mother to try sleeping on her left side - a good way to improve blood flow to the baby.
Lifestyle changes at 9 weeks pregnant
As with earlier weeks, there may be lifestyle modifications that need to be made during pregnancy:
During pregnancy, it is important for the mother to take care of herself and the developing baby. Drinking alcohol and smoking must be avoided during pregnancy, along with all other toxic substances such as drugs.
Pregnant women should discuss all medications they are taking with a doctor to ensure that they are safe to be taken throughout pregnancy. Eating a healthy diet and taking a good prenatal vitamin is also important.
Another way to help maintain health during pregnancy is to get 30 minutes per day of exercise such as yoga, walking, or swimming.
Using permanent hair color is not recommended during the first 12 weeks of pregnancy; instead, semi-permanent dye is a good option.
While it is safe to eat fish during pregnancy, it is recommended that intake is limited to 8-12 ounces of fish and shellfish per week.
Some examples of fish which are safe to consume during pregnancy include shrimp, canned light tuna (note: mercury varies can to can), pollock, catfish, salmon, anchovies, herring, sardines, trout, Atlantic and Pacific mackerel, and cod. It is recommended to limit consuming more than 6 ounces per week of albacore tuna and tuna steak.
It is most important to avoid shark, swordfish, tilefish, and king mackerel while pregnant, as they have high levels of mercury which can be harmful to a baby's brain and nervous system.
If you have questions regarding your pregnancy, be sure to contact your health care provider.
Call your doctor if you are experiencing symptoms of an ectopic pregnancy or miscarriage such as vaginal bleeding or passage of tissue, leaking vaginal fluid, feeling faint or dizzy, low blood pressure, rectal pressure, shoulder pain and severe pelvic pain or cramping.