How much weight should a twin pregnancy gain during pregnancy? Do I need to take twice as much folic acid and calcium as a single pregnancy?

Author: Sun Yu, Chief Physician, Peking University First Hospital

Reviewer: Zou Liying, Chief Physician, Beijing Obstetrics and Gynecology Hospital, Capital Medical University

Many families like twins, thinking that it is convenient to have two at a time, and two babies who look similar are also very cute. Do you think so too?

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Do you know which families are more likely to have twins? What should pregnant women with multiple pregnancies pay special attention to during prenatal care? How much weight should pregnant women with twin pregnancies gain during the entire pregnancy? Do pregnant women with twin pregnancies need to take twice as much folic acid, iron and calcium as pregnant women with single pregnancies?

Let’s take a look together.

1. Which families are more likely to have twins or multiple births?

Generally speaking, multiple pregnancies are related to genetics, so families with a genetic history, such as families that have given birth to twins before, are more likely to have twins again.

During the process of natural pregnancy, multiple pregnancy is not only related to genetics, but also to the age, parity, nutritional status, etc. of the pregnant woman.

Under natural circumstances, the incidence of twin pregnancy is about 1/80, and the incidence of triplet pregnancy is about 1/8000-1/7000.

However, in recent years, due to the development of assisted reproductive technologies such as ovulation induction technology and in vitro fertilization, it seems that multiple pregnancies are becoming more and more common.

Although everyone thinks that being pregnant with twins or even multiples is very lucky and happy, in fact, pregnant women with twin pregnancies are in a high-risk pregnancy. Because twin pregnancies put a heavier burden on the uterus, various maternal and fetal complications are prone to occur.

2. What special attention should pregnant women with multiple pregnancies pay during prenatal care?

Because there are more complications for both the mother and the fetus in multiple pregnancies, there are definitely some areas that require extra attention in prenatal care.

For example, the mother is particularly prone to anemia. Compared with a single baby, the anemia will be more serious and she will be more likely to develop complications such as gestational hypertension and gestational diabetes.

In addition, for the mother, the incidence of dystocia, postpartum hemorrhage, and premature birth during the entire delivery process will be higher than that of a single pregnancy.

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Therefore, in prenatal care for twin pregnancies or even multiple pregnancies, we should pay more attention to the mother.

For the fetus, compared with a single pregnancy, due to the difference in chorionicity, the fetal complications that occur will also have some special features. Therefore, during the entire pregnancy, pregnant women with twin pregnancies have significantly more ultrasound examinations than those with single pregnancies.

The purpose of ultrasound examination is actually mainly to check some problems in fetal development, such as twin-twin transfusion syndrome and twin developmental discordance. These problems can only be diagnosed under ultrasound.

3. How much weight should a pregnant woman with twin pregnancy gain during the entire pregnancy?

This is mainly based on the basic weight of the pregnant woman, which means that each of us is fat or thin, so in medicine, a body mass index (BMI) is used to represent a person's fatness or thinness.

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If a person's BMI is greater than or equal to 30, we consider that person to be obese, and if the BMI is between 18.5-24.9, we consider that person to be of normal weight. So if a person is too thin, we would recommend that she gain more weight during pregnancy, and if a person is too fat, she should gain less weight during pregnancy, so this is related to her basic weight.

For a person of normal weight, it is recommended that pregnant women with twins gain 17-20 kg during pregnancy. For pregnant women with single babies, we generally believe that people of normal weight only need to gain 12-15 kg during pregnancy.

Therefore, the weight gain standard for twin pregnancy is definitely higher than that for single pregnancy.

4. Do pregnant women with twins need to take twice as much folic acid, iron, and calcium supplements as those with singleton pregnancies?

No.

Whether to supplement and how much to supplement should be determined based on the examination results of the pregnant woman, rather than blindly thinking that if you are pregnant with twins, you should multiply everything by 2. It is not really double, because drugs still have dosage limits, and all drugs have side effects.

But for twin pregnancies, more nutrients are definitely needed because they have to meet the growth and development needs of two fetuses. Therefore, nutritional deficiencies, including deficiencies in trace elements, which is what we often call iron and calcium deficiency, are definitely more obvious in pregnant women with twin pregnancies than in pregnant women with single pregnancies.

Therefore, during the entire pregnancy, our final indicator is to look at her weight gain. At the same time, we also need to monitor her nutritional intake to see if it meets the requirements of the dietary pyramid. The intake of protein, fat, carbohydrates and trace elements must meet certain standards.

Therefore, for a pregnant mother with twins, the nutrients she consumes throughout the pregnancy process must be balanced and reasonably combined, and the types and amounts of nutrients consumed must be higher than those for a single pregnancy.