So we are at 21 weeks along, though I say that because we are 20 weeks and 2 days, so that to me means in the beginning of week 21 right? Who the heck knows. I've seen all sorts of online calculators but I enter the same info and they give me different calculations on due dates and such, and with twins they are full term at week 37 anyway. I'm not really sure what week begins or ends a trimester because apparently there are 3 different ways to calculate it, though around 27 week mark seems about right:
by Development:This uses actual developmental stages to divide up a pregnancy. From LMP to 12 weeks the embryo develops all the major organs and becomes a fetus. From 12 weeks to 27 weeks the fetus continues developing and reaches viability. From 27 weeks on the fetus finishes development and prepares for delivery. Here the second trimester begins at 12w 0d and the third at 27w 0d.
by Gestation:With this method you take the 40 weeks of gestation and divide into three equal stages. Here the second trimester begins at 13w 3d and the third at 26w 6d.
by Conception:This method is where you take the 38 weeks of post conception development, divide by three, into the three equal trimesters. Here the second trimester begins at 14w 5d and the third at 27w 3d.
What is the length of the first, second and third trimesters?
The length of the trimesters is often a source of confusion. The word trimester means 'three months'. Three periods of three months each, gives pregnancy a beginning, a middle and an end period.
These periods match the developmental stages to divide up a pregnancy.
- Beginning: From LMP (last menstrual period) to 12 weeks the embryo develops all the major organs, becomes a fetus, and the placenta takes over control.
- Middle: From 12 weeks to 27 weeks the fetus continues developing and reaches viability.
- End: From 27 weeks on the fetus finishes development and prepares for delivery.
So when you get these scans from Dr. Patel, what are you supposed to do with them? Other than trying to figure out what part of the baby you are looking at, of course... I am not sure on most of them what I'm seeing if it isn't the head, and lately they seem to get even blurrier and harder to tell instead of easy like the first ones were. Maybe they are doing more close ups. Dunno, but this latest scan is the first time we have gotten shots that appear to the be fancier 3D Doppler kind. It says on the report "2D Echo" so that is probably what refers to these two shots. Check them out! The 2nd one I don't have much of an issue telling what I'm looking at on the left side, but the 1st one I have no idea what is in front of my the baby on the right. Is that the other baby's feet or something?:
I'm not going to pay out of pocket for a local radiologist to look them over when Dr. Shah (Anand radiologist on report) and Dr. Patel already have and say everything is fine. That would be going overboard. Okay, okay...so I did have my Dad call in a favor and forward the last two to a radiologist friend just to see if he could determine gender. He isn't sure cause they are scanned in with big fax stripes and so blurry by the time we get them by email, but he agrees we may have at least one girl. But I can scarcely see the A or B mark on each pic that tells you which pic is for which baby, so unless you have a double gender shot with both babies in it (highly unlikely) or see a boy and a girl clearly, you won't know which twin you are looking at in each photo and could think you have two boys when you are looking at the same boy for example. Plus they don't tend to take shots from the right angle since they aren't really trying to detect gender. I don't honestly care because I just want them healthy, but it would make packing clothes so much easier because gender neutral stuff is harder than I thought to find. I can tell you that when you see a split screen pic with two images in it that it seems to be of the same baby every time.
So what does all of it mean beyond the pictures? I just go to the very bottom and look for the sentences first, since it is easiest to understand and seems to sum it all up. I'll put what I've been able to decipher from Googling, but I'm just a layperson and NOT a doctor or radiologist so I could be very wrong. I know a bunch about physiology and anatomy from taking two college courses for fun on the subject and getting my Emergency Medical Technician in 1995, but that hardly makes me an expert so take everything below with a grain of salt. I assume if there is a real problem Dr. Patel would email you and tell you. It says stuff like:
- DCDA twin pregnancy-Dichorionic/diamniotic twins. It means they are fraternal and don't share an amniotic sac. This is good because there is no risk of twin-to-twin transfusion syndrome. If it was monochorionic (MA) they would be identical twins. The chorionic part is actually referring to the placenta, and sharing a placenta means the syndrome above is a possibility. Identical twins are the only kind that can share an amniotic sac, and there is a high survival rate but there is an added risk of cord entanglement or compression.
- Variable presentation. That seems to simply mean the baby moves around and doesn't stay stuck in one spot. From what I understand, that is a good thing.
- Posterior high placenta. That means the placenta is in the back of the uterus. This is good, and I think where Dr. Patel tries to get the embryos to implant on purpose since both of our twins implanted there. A low lying placenta is the only place I know that is definitely bad, but I'm not sure what medical term that would be. That means there is a chance of "placenta previa" and the baby will have to be born by C section. Google it. So when you see "no previa" on a report that is a good thing.
- Fetal growth 7 AF normal. Sounds good to me. I think AF is amniotic fluid. Not sure what the 7 is for. I found AFI charts online to show normal fluid levels, but I can't interpret it that in depth and it is probably different in twins.
- Fetal heart normal. Awesome!
- Low resistance flow in both uterine artery--PIH least likely. PIH means Pregnancy Induced Hypertension, so least likely is a good thing. That means low resistance flow in the uterine arteries are a good thing too.
- No fetal malformation. Definitely good.
- No growth discordance. This is good. It means one is not growing significantly faster than the other.
- EFW-Estimated fetal weight. Ours is in grams, but it shows the conversion to lbs too.
- Note* In the measurements section there appears to be a column for "last" measurements to measure growth. Ours is always the same number as the most current measurements on every report, so I think he doesn't re-enter old data in the new reports for whatever reason. So don't freak out and think your baby hasn't grown.
- LMP-Last Menstrual Period: This is a way of calculating the gestational age.
- GA-Gestational age: This column is next to all the measurements from the fetal biometry section I describe below. You want this to be close to
- EDD-Estimated date of delivery. I think in the first column it is calculating it based on the LMP and the other based on GA, which makes sense because I've seen that there are several ways of calculating due date and these are two ways. This never seems to change more than a day or two for us and reflects the 40 week date. With twins 37 weeks is full term though, and delivery can depend on other factors and 35 weeks is frequent with Dr. Patel and twins.
- HR-Heart rate. It starts off in the very early weeks the same as the mother's, then by week 9 rises to 175 BPM (beats per minute). In the middle of the pregnancy it is often 120-180 BPM.
- NT-Nuchal Translucency. Ours says normal at the very bottom, which is good. See more about this below.
- NB visible. I think this means nasal bone. I take it that it should be visible, so woo hoo! This was right next to "nasal triangle normal" so that makes sense.
- Fetal biometry is basically the section where they take various measurements of your baby in order to determine the fetal growth is normal. On some scans they have done a side by side comparison in a separate section to establish any growth discordancy. This linke shows charts of what is normal percentiles if you want to totally obsess about it: http://www.centrus.com.br/DiplomaFMF/SeriesFMF/18-23-weeks/appendix-03/normal_fetal_biometry/appendix-03.htm Abbreviations from this section as follows:
- BPD - biparietal diameter: Transverse diameter of the head between the protuberances of the two parietal bones of the skull
- OFD- occipito-frontal diameter: The diameter of the fetal head from the external occipital protuberance to the most prominent point of the frontal bone in the midline.
- HC-head circumference.
- AC-abdominal circumference
- FL-Femur length (thigh bone)
- HUM-I think this is humerus length, but not sure.
- The names Hadlock, Jeanty, Hansmann are all referring to which growth table the doctor is using on that particular measurement on the scanner.
- Fetal cranium: This section is all about measurements of the head, including the left ventricle, the cisterna magna (CM), and cerebellum (CEREB).
- Ratio section: These have the previous mesurements in a ratio format. It takes these ratios and compares them to a normal growth chart, and the percentages on the right show you what is normal for how many weeks along your baby is. You want it to be somewhere in that percentage range.
- 2d Echo section: ASC AO stands for ascending aorta and MPA diam stands for main pulmonary artery. These kinds of scans I think are designed to check for good blood flow on major arteries, so that makes sense because it doesn't get more major than these two arteries in the human body. This section also has measurements on the uterine artery flow, which admittedly is way too hard to interpret. But the summary section at the last page will say what it did on ours hopefully that I referred to above, which tells you all is okay. We had another report that had similar abbreviations and a section for "Ductous Venousus," (DV) which appears to be an important fetal vein that shunts approximately half of the blood flow of the umbilical vein directly to the inferior vena cava.
- PI Pulsatility indexRI Resistance index, Pourcelot’s indexS/D ratio Systolic/diastolic ratioVmax Velocity maximum (same as PSV and MPSV)MDV Minimum diastolic velocityPPI Peak to peak pulsatility indexPSV Peak systolic velocity (same as MPSV and Vmax)MPSV Maximum peak systolic velocity (same as PSV and Vmax)TAMV Time averaged maximum velocity (same as TAMX and TAPV)TAMX Time averaged maximum velocity (same as TAMV and TAPV)TAPV Time averaged peak velocity (same as TAMV and TAMX)
- Cord-3 vessels is what you want and is normal. 2 can still result in a live birth but poses more risks.