It is sometimes necessary to deliver a baby before 39 weeks due to health concerns for either mother or baby. Some reasons include: placental previa, cholestasis, pre-eclampsia, gestational hypertension or IUGR (your baby not growing adequately). Your health care provider might first choose to determine if your baby’s lungs are mature before making the final decision to deliver. If so, you will be sent to the hospital or clinic for an amniocentesis. An amniocentesis is a relatively safe procedure whereby a physician aspirates some amniotic fluid from the amniotic sac (bag of waters) and sends it to a lab for processing.
On the day of your procedure, you may be told you can eat lightly or not at all. Ask what your institution’s policy is. Come to the hospital in comfortable clothing; you may be offered to change into a patient gown. You’ll need an NST and AFI to determine fetal well-being and adequate amniotic fluid prior to your amniocentesis. There will be an informed consent for you to sign. The risks are minimal, but should be discussed with you by the doctor performing the procedure prior to your signing the consent form.
The doctor will need to do a bedside ultrasound to determine where the best pocket of amniotic fluid is for aspiration. He/she checks for placental and umbilical cord location, and which position your baby is in. This usually takes just a few minutes.
Your provider will then set up the contents in the amniocentesis tray, and prepare you for the procedure. You will need to lay flat with or without a wedge underneath one hip (to offset uterine pressure on the vena cava). Your provider will open the sterile tray; prepare the specimen tubes, procedure equipment, and local anesthesia if preferred. Since an amniocentesis is a sterile procedure, the area where the needle will be placed will be washed with cool Betadine sponges, and then the surrounding area will be covered with a sterile drape. The ultrasound machine will be used again to determine an adequate fluid pocket and then used as a guide as fluid is aspirated. Some providers use a local anesthetic. A needle is then introduced through the skin and into the amniotic sac. Placement is verified, a syringe is attached to the needle, and fluid is aspirated and then transferred to a glass specimen tube for transfer to the laboratory. If you have ample fluid that is located easily, the needle aspiration should only take a minute or two. Your abdominal skin is quite stretched and taught; most women do not feel much discomfort from the needle insertion. You may experience some cramping during the aspiration.
After the procedure, you will be placed back on the external fetal monitor to ensure fetal well-being. Occasional contractions are not uncommon. There should be minimal to no discomfort following the procedure. It is important to call your provider if you experience vaginal bleeding, loss of amniotic fluid, decreased fetal movement, regular painful contractions or excessive pain at the insertion site. Ask your provider what your activity level can be for the rest of the day. Most often you can return to your normal routine.
Obtaining the results from the amniocentesis, whether your baby’s lungs are mature, vary from institution to institution. Many take just a few hours while others may take a day or two. Your provider should get in touch with you to discuss your results and what plan of action is recommended. Keep in mind that the amniocentesis was done to determine if your baby can be delivered early, so be prepared for the recommendation of an induction or cesarean section depending on your circumstances.