Multiple Pregnancy

Multiple Pregnancy

What is a multiple pregnancy?

The development of more than one pregnancy in the womb is medically classified as a multiple pregnancy. While it is a relatively rare phenomenon, it has become more common in recent years due to the more widespread use of fertility drugs and assisted reproduction techniques.

Why does it occur?

Multiple pregnancy can occur if two or more eggs are released from the ovary and fertilised at the one time (fraternal) or if a single ovum divides at an early stage of development (identical). Today, most pregnancies with three or more babies are the result of the use of fertility drugs.

In the case of triplets, two babies may be identical (ie. arising from a single ovum or egg) while the third may be completely different, arising from a different ovum. The non-identical baby develops in its own placenta, while the identical babies will share a single placenta. However, it is possible for the three babies to be identical and to share the same placenta.

Is it hereditary?

There seems to be some hereditary links in multiple pregnancy, since the production of twins or triplets appears to run in families. However, there are also many incidences of multiple births in families who have no history of this phenomenon.

Twins occur naturally in about 1 in 80 pregnancies, triplets in about 1 in 8,000 and quadruplets in about 1 in 73,000 pregnancies.

How do the babies develop?

It is very rare for babies in a multiple pregnancy to develop at exactly the same rate. It is also possible for one baby to die in the womb while the remainder continue to develop normally. Careful monitoring of the growth rate of the babies will be carried out throughout the pregnancy and ultrasound scans will be performed on a regular basis to assess the development of the foetuses.

How is it diagnosed?

A multiple pregnancy will usually be diagnosed on ultrasound scan.

What are the risk factors?

From a medical viewpoint, it is undoubtedly much more difficult to manage a multiple pregnancy than a single pregnancy. There are greater risks to both mother and babies. The mother is at a higher risk of developing raised blood pressure; pre-eclampsia; oedema; anaemia; excessive weight gain and premature labour. The latter is a hazard of every multiple pregnancy. Obviously premature labour and delivery is potentially more dangerous for the babies.

How important is rest?

Rest and relaxation are important in any pregnancy, but their importance takes on an added significance in multiple pregnancy. The only real way in which the onset of labour can be delayed in a multiple pregnancy is for adequate rest to be taken, however difficult that may be.

Since there is a great deal of abdominal enlargement in multiple pregnancy, many women become so uncomfortable that they have no option but to slow down and take things easy. Breathing can also cause problems, and towards the end of her pregnancy, the woman may find it virtually impossible to breathe while lying flat so she may have to sleep in a semi-upright position.

Are the babies always premature?

In almost every case of multiple pregnancy, the babies will be premature, although the degree of prematurity depends on the stability of the pregnancy and the health of the mother.

Although labour and delivery may proceed as in a single pregnancy, many medical professionals favour delivery by Caesarean section as it is believed to be safer, especially for the third and fourth babies.

The size of the babies is not the most important aspect. The really important factor is their maturity. All babies born after a multiple pregnancy will be placed in incubators in the special care unit so that their condition in the first days of life can be monitored around the clock.

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