Getting Pregnant with Twins: Causes, Symptoms & Investigations
There aren`t few cases when the couples that expect a child go to the ultrasound to find out the sex of the child only to be amazed that they`ll be parents of twins. However, getting pregnant with twins is both a blessing as well as a burden.
Table of Contents
- 1 Getting Pregnant with Twins
- 2 Causes: What Are the Odds of Having Twins?
- 3 Complications
- 4 Symptoms
- 5 Investigations
- 6 Treatment
Getting Pregnant with Twins
Getting pregnant with twins should be more than a strong desire or a lifetime dream. A pregnancy with 2 fetuses is known as a twin pregnancy, or a multiple pregnancy – especially if there are more than 2 fetuses. The fetuses can be monozygotic or heterozygous.
Monozygotic twins (identical twins) come from the same egg resulted from the fertilization of an egg by sperm. For unknown reasons, the fertilized egg splits into 2 or more embryos during the first stage of development. Monozygotic twins share the same placenta – spongy vascular organ that is engaged in the uterus and through which the exchange of substances between the mother`s organism and embryo is made during pregnancy. Usually, they grow inside 2 distinct amniotic sacks in the uterus. Rarely, monozygotic twins share the same amniotic sac – the membrane in the interior of the uterus where the fetus and amniotic sac can be found.
- Are of the same sex and have the same blood type;
- They don`t always look exactly the same; one can be right-handed, while the other one left-handed;
- Monozygotic twin pregnancies appear mostly by chance; they aren`t related with age, race or family history.
Dizygotic twins, or fraternal twins, come when 2 or more eggs are fertilized by 2 different sperm. They also have different placenta and amniotic sacks.
- May have different sex and different blood types;
- May not resemble one with the other, showing different colors of hair or eyes, or may be similar such as brothers from successive pregnancies;
- Tend to come from families with a history of multiple pregnancies.
Babies conceived after a treatment of infertility are most of the times dizygotic twins, not monozygotic.
Causes: What Are the Odds of Having Twins?
Infertility Treatment – Once the infertility treatment is applied, from 1980 until today, it was noticed that the rate of twin pregnancies has doubled, and the percentage of pregnancies from which has resulted triplets or more babies has increased almost 5 times. By using assisted reproductive techniques and medication for the infertility treatment, the probability of multiple pregnancies increases.
The drugs used in the infertility treatment stimulate the release of more eggs from the ovary, therefore the increased probability of multiple pregnancies.
The assisted reproductive techniques refer to the direct transfer of embryos (the initial phase of development of an animal or human organism, from the fertilization of the egg until the complete formation of organs) in the uterus to increase the probability of becoming pregnant. Overall, 25% to 30% from all pregnancies obtained this way are twin pregnancies, 5% of them are pregnancies with triplets, and less than 1% of them are pregnancies with 4 or more babies.
Other Causes: Certain risk factors increase the probability of multiple pregnancies:
- Age – Such a factor is when the mother is over 30 years old, and when she is over 40 years old, heterozygous twins are more frequent;
- Race – Twins are more frequent at African women, especially at those with ages between 35 and 45 years old; they are less frequent at Asian women;
- Physiological personal history case – If the woman has already had a heterozygous multiple pregnancy, the chances for such a pregnancy to reaper will double;
- Family history – If the woman has a family history of heterozygous multiple pregnancy, then the chances for a future twin pregnancy are higher; however, the risk for a multiple pregnancy isn`t increased in case of a family history at the father;
- Synchronization – Twin pregnancies are more frequent at the first menstrual cycle which appears after stopping the use of oral contraceptive.
A twin pregnancy increases the risks of the mother as well as the product of conception to develop problems during pregnancy.
The risk for various medical conditions will increase with every additional fetus, such as: miscarriage, premature birth, gestational diabetes, preeclampsia, premature detachment from the placenta, placenta praevia, urinary tract infections, anemia, birth by C-section, pulmonary embolism (the sudden obstruction of pulmonary vessels with emboli: thrombus, amniotic fluid, etc) and major bleeding after birth.
During twin pregnancies, fetuses show a high risk of developing genetic and birth defects. Children born from such pregnancies also have a increased rate of health issues after birth because they are born prematurely.
Women who experience a twin pregnancy can have the same symptoms as women who are pregnant with one single fetus, but these signs can appear earlier and can become more pronounced.
A twin pregnancy can produce:
- Excessive morning sickness and vomiting during the first trimester;
- Weight gain;
- Back pain;
- Larger sizes of the uterus than normally for the gestational age;
- More fetal movements than expected during the second and third trimester.
These signs will appear later in during the evolution of the pregnancy:
- Varicose veins;
- Back pain;
- Shortness of breath caused by the augmentation of pressure in the lungs due to the compression exerted by the pregnant uterus against the diaphragm – the muscle that separates the chest cavity from the abdominal one;
- The increase of the abdominal girth;
- Preeclampsia – severe deficiency of the blood flow and blood pressure which affects both the mother and fetus;
- Premature birth.
In the past, women didn`t know that they carry twins until the end of the pregnancy. Since the discovery of more advanced exams, twins and multiple pregnancies are diagnosed during the first and second trimester.
Tests Used in Diagnosing Twin Pregnancies
- Human chorionic gonadotropin (hCG) is the pregnancy hormone produced by the placenta since the early pregnancy; the blood or urine are tested for the discovery of this hormone; an increased level of chorionic gonadotropin is a possible sign of twin or multiple pregnancy;
- Fetal ultrasound: can show the presence of more fetuses in the uterus; in case of a multiple pregnancy, there`ll be numerous ultrasounds performed during pregnancy to monitor the development of the fetus and amniotic fluid;
- Alpha-fetoprotein (AFP): is a substance produced by the fetus; the blood test for this marker is performed during the second trimester to investigate possible congenital abnormalities; an increased level can also be suggestive for the diagnosis of a twin pregnancy; increased values of this marker will obligate for performing of an ultrasound control.
Starting with the 18th gestational week, an experienced doctor can detect the heartbeats of the fetal cord in a multiple pregnancy and on touch can feel more than one single fetus.
Tests Used in Diagnosing Genetic and Congenital Abnormalities
The fetuses for twin pregnancies show an increased risk to develop genetic and congenital abnormalities.
The placental biopsy uses a placental fragment obtained using a thin tube passed through the vagina and cervix (cervix, the inferior part of the uterus) until the uterus. The biopsy and genetic testing of the obtained fragment is made between 10th and 13th weeks of gestation. Then, the procedure is more difficult to be made.
Amniocentesis uses a small amount of amniotic liquid obtained by transabdominal puncture. Amniocentesis and genetic tests of the collected fluid is made ideally between 15th and 18th weeks of gestation. Amniocentesis is sometimes more utilized during the last trimester of pregnancy to be seen if the fetal lungs are sufficiently mature to handle the breathing process after birth.
The placental biopsy and amniocentesis show a small risk of provoking an abortion when they are utilized in the investigation of a twin pregnancy (when it comes to the investigation of a pregnancy with one single fetus, the placental biopsy has a higher risk of complications than in a multiple pregnancy). To make decision about the treatment or continuation of a pregnancy when it was opted for this procedure of diagnosis, the information offered by the placental biopsy is required to be seen by a doctor immediately.
Tests Used to Monitor the Mother and Fetus
- Blood pressure during pregnancy is monitor at each medical exam to detect early preeclampsia;
- Lab tests, such as the iron level in the blood (serum iron), the number of erythrocytes (red blood cells), hemoglobin, are used to detect iron deficiency anemia (anemia appeared from lack of iron); anemia is a frequent problem at women with twin pregnancies because the fetuses consume a large amount of the mother`s iron reserves;
- Urinalysis and urine culture examination (lab sample which investigates the microbial culture from the urine);
- Transvaginal ultrasound is used to measure the length of the cervix; a short cervix increases the risk of premature birth;
- Fetal heart rate monitoring is used before or during labor to ensure the safety of the product of conception.
It`s important as during pregnancy, the future mother to be more careful than usually.
Getting Pregnant with Twins Naturally
When it comes to a twin pregnancy a balanced diet is very important, which needs to include calories of good quality, rich in calcium, iron and folic acid.
It`s expected as the weight gain during a twin pregnancy to be bigger than in a pregnancy with one single fetus. Each fetus means for the future mother an additional weight gain during pregnancy. For a woman who when she becomes pregnant she has the ideal waist figure, it`s expected as during pregnancy to gain weight as it follows:
- In a pregnancy with one fetus with 11,3 – 15,9kg;
- In a twin pregnancy with 15,9 – 20,4kg;
- In a pregnancy with triplets with 20,4 – 22,7kg;
- In a pregnancy with 4 fetuses with 22,7 – 25kg.
Note: Of course, these intervals of weight are changing if at the beginning of the pregnancy the pregnant woman is over-weighted or under-weighted.
Conduct in a Multiple Pregnancy
When we are talking about 2 or more fetuses in a multiple pregnancy, their risk of dying intrauterine or to suffer irreversible alterations is directly proportional to their number.
If it`s about 3 or more fetuses resulted from the application of a fertility treatment, it`s possible to rely on a process of reducing the number of fetuses in the uterus, which increases the probability for the remaining fetuses to survive and reduce the risks for the pregnant woman. This procedure has some risks, the most important one being that an abortion might be provoked. The decision to choose this procedure is a difficult one as well as traumatic from a psychological point of view. It must be taken along with the obstetrician as well as taking into account the risk-benefit ratio. Psychological counseling is essential and it also must be taken into consideration when necessary.
When deciding to choose a procedure of reducing the number of fetuses in the uterus in a multiple pregnancy it must be taken into account also the fact that this type of pregnancy involves an increased risk of premature birth. It`s recommended a set of measures to avoid the appearance of such complications, such as: avoiding certain activities, avoiding sexual contacts, bed rest, the frequent monitoring of fetal vital signs, hospitalization for treatment with steroids to accelerate fetal lung development.
Tocolytic treatment (medication which causes uterine relaxation and prevents the contractions of the smooth muscles from the uterine walls) can also be useful in avoiding premature birth. Tocolytic treatment also involves risk such as pulmonary edema, that`s why tracking the pregnant woman is essential. Pulmonary edema is more frequent in tocolytic therapy at pregnant women with multiple pregnancies.
There aren`t any evidence that bed rest or avoiding physical effort would prevent premature birth. Still, these rules are sometimes recommended. Consulting a physician is necessary to determine if such a conduct is beneficial for the development of the pregnancy.
Outpatient Treatment (At Home)
A multiple pregnancy can provoke pronounced morning sickness during the first months of pregnancy. These symptoms can be treated at home as long as they don`t cause dehydration or malnutrition states to the mother.
Signs of labor include:
- Cramps similar to those that occur in menstruation;
- Abdominal cramps, sometimes accompanied by diarrhea;
- Uterine contractions at every 10 minutes or less;
- Feeling of lumbar pressure (loin region);
- Increased volume of vaginal discharge.
When the signs which suggest that the labor may appear, you should contact a doctor. Also, medical consult and hospital visits will be required when the “water breaks” or vaginal bleeding appears.
In a twin or multiple pregnancy, it`s recommended:
- Adequate caloric intake and proper intake of calcium, iron and folic acid (they are part of the group of vitamin B and has an important role in DNA synthesis; deficiency of folic acid leads to megaloblastic anemia);
- Avoid alcohol, smoking, certain medications, chemical and cosmetic products, exposure to X –rays (radiographs, CT scans, etc), avoiding excessive consumption of caffeine (coffee), exposure to extreme temperatures, consumption of contaminated food;
- Reduce physical effort (in a multiple pregnancy, lots of doctors recommend the termination of stressful physical activities after the 24th week); you should contact the doctor when it comes to activities such as swimming or walking;
- Rest, especially starting with the week 24; although studies have shown that strict bed rest doesn`t prevent premature birth, bed rest is still recommended when there`s a risk of preterm labor;
- Changing daily activities to ensure a smooth pregnancy evolution and compliant at the doctor`s advices related to reducing physical activities;
- Periodic medical consultations for tracking the pregnancy: biweekly after the 20th week and every weekly after the 30th week.
Breastfeeding can be a real challenge for the mother in a multiple pregnancy that was carried through, but the satisfactions are worth it.
In the process of development of the babies it should be pursued the type of personality of each one and based on it, gradually, they`ll be helped to shape their own individuality. In all this process, it`s required a lot of patience and a lot of time to be spent with each and every one of them.
A twin or multiple pregnancy increases the risk of intrauterine death of the fetuses as well as the post partum risk of death in newborns. When such tragic events appear, family support, friends and counseling can play an essential role in the alleviation of the parents` suffering.