The diagnosis of twin pregnancy should be simple. It ought to be obvious that two babies are present; that the uterus is larger than it would be for one baby and that there are two of everything including two fetal heartbeats. In fact about 8% of twin pregnancies reach delivery before the discovery of the second baby – usually to the equal embarrassment and astonishment of the doctors as well as the mother.
The following factors may make the doctor consider the possibility that you might be having twins:
- Excessive nausea and vomiting – may be associated with a twin pregnancy, especially if the symptoms continue beyond the 13th and 14th week.
- The uterus – is consistently larger than the dates suggest. Pelvic examination is performed at the first visit to the doctor or the antenatal clinic and the presence of any fibroid or tumors is noted. If the uterus is subsequently noted to be larger than the dates it is essential to know that a previous pelvic examination has been performed to exclude any other pelvic mass.
- Fetal movements – are felt in a twin pregnancy at the same time as they would be felt in a single pregnancy. As pregnancy advances, however, excessive movements may lead the mother to believe she might be carrying twins.
- The fetal hearts – it used to be very difficult to confirm the presence of a twin pregnancy by listening to the fetal hearts through the ordinary fetal stethoscope, but the sonogram will detect the presence of two fetal hearts as early as the 14th week.
- Acute hydramnios– usually accompanies a uni-ovular (identical) twin pregnancy. During the 24th week there is a rapid and dramatic enlargement in the size of the uterus. This may be so sudden that it causes considerable pain and discomfort and the abdominal girth may increase within a few days. This only occurs in identical twin pregnancies because the circulation of one twin becomes so dominant that the other twin is forced to produce a large quantity of amniotic fluid to prevent itself from getting heart failure.
- Many fetal parts – the doctor’s suspicion is aroused if an excessive number of fetal parts are felt within the abdomen, especially if two heads are palpated.
- Pre-eclampsia – does not usually occur until after the 32nd week of pregnancy, but a raised blood pressure or excessive weight gain before the 28th week is associated with twin pregnancy.
- Predisposition to having twins and/or heredity – if there are twins in the mother’s family, or the woman is of advanced age, these can increase the possibility of a twin pregnancy. The use of fertility drugs to stimulate ovulation, and in vitro fertilization are also factors that make a woman more likely to have twins.
- Ultrasound (sonogram) – the routine use of ultrasound in early pregnancy also helps to diagnose twins in early pregnancy. This is one of the trusted methods of determining a twin pregnancy. On the ultrasound monitor your doctor can easily distinguish two fetuses or two heartbeats with ease.
Some of these symptoms are probability that you may be having twins. Till date the ultrasound remains the most trusted of all the methods of diagnosing twin pregnancies. It’s only in rare cases that the ultrasound has failed, usually due to the position of the babies.