Twin survival rate by week

Premature birth statistics | Tommy's

Tommy's PregnancyHub

A preterm birth is one that happens before 37 weeks of pregnancy. Globally, more than 1 in 10 pregnancies will end in preterm birth.

A preterm birth is one that happens before 37 completed weeks of pregnancy.

The World Health Organisation gives the following definitions for the different stages of preterm birth:

Extremely preterm: before 28 weeks
Very preterm: from 28 to 31 weeks
Moderate to late preterm: from 32 to 37 weeks.

General UK premature birth statistics

Around 8% of births in the UK are preterm. That is around 60,000 babies each year.
This is higher than many countries in Europe and higher than Cuba and Iran

Of the births that were preterm in the UK:

5% were extremely preterm (before 28 weeks)
11% were very preterm (between 28 and 32 weeks)
85% were moderately preterm (between 32 and 37 weeks).

In 2019, live births where gestational age was under 24 weeks increased to 0.15% compared with 0.13% in 2018 and 0.11% in 2010.

Chances of survival following preterm birth

Medical advances mean that we are getting better at treating preterm babies but the chances of survival still depend on gestational age (week of pregnancy) at time of birth.

Less than 22 weeks is close to zero chance of survival
22 weeks is around 10%
24 weeks is around 60%
27 weeks is around 89%
31 weeks is around 95%
34 weeks is equivalent to a baby born at full term.

Preterm birth and neonatal death

Complications arising from premature birth is the leading cause of neonatal death (death in the first few weeks after birth) in the UK.

Preterm birth and multiple pregnancies

Having more than one baby is a risk factor for preterm birth. On average, most singleton pregnancies last 39 weeks, twin pregnancies 37 weeks and triplets 33 weeks.

Risk of prematurity with singleton pregnancy: 7%
Risk of prematurity with multiple pregnancy: 57%

Risk of disability in preterm children

Generally, the earlier the birth, the higher the risk of problems. However these are only statistics and cannot predict how an individual child will do; some extremely premature babies do very well and develop into healthy children.

1 in 10 of all premature babies will have a permanent disability such as lung disease, cerebral palsy, blindness or deafness.
1 in 2 of premature babies born before 26 weeks of gestation will have some sort of disability (this includes mild disability such as requiring glasses).

In one study of 241 children born before 26 weeks' gestation the following was found:

22% severe disability (eg cerebral palsy + not walking, low cognitive scores, blindness, profound deafness)
24% moderate disability (eg cerebral palsy + walking, IQ/cognitive scores in the special needs range, lesser degree of visual or hearing impairment)
34% mild disability (defined as low IQ/cognitive score, squint, requiring glasses)
20% no problems.

Preterm birth by ethnicity

The latest statistics from the Office for National Statistics show the percentage of preterm births by ethnicity in England and Wales.

Since 2021. babies from Black ethnic group have had the highest proportion of preterm births since data collection began in 2007.

Between 2020 and 2021, the biggest percentage increase in preterm live births was in the Asian ethnic group, from 7.5% to 8.1%.

These statistics show the percentage of preterm births by ethnicity in 2021:

Black: 8.7%
Asian: 8.1%%
White: 7.4%
Mixed or Multiple:7%
Any Other ethnic group: 7%

Causes of preterm birth

In some cases a cause of preterm birth can be shown but more often it is unknown or unclear.

In 1 in 4 preterm births, the birth is planned (induced labour or c-section) to save the life of mother or baby from pregnancy complications such as pre-eclampsia, fetal growth restriction, waters breaking early (PPROM) or infection

Preventing premature birth

Too often health professionals are not able to tell women why they have had a premature birth. This area of research is underfunded, with many taking an unhelpful (and unique to pregnancy) approach of ‘It was not meant to be’.

Research into why premature birth happens is the only way we can save lives and prevent future loss. Tommy's funds more than £400k of research into premature birth every year. We are focused on predicting early which women will have a premature birth and treating them to prevent it happening.

Read about our research into prematurity here.

What to expect if your multipes have to spend time in the NICU

Updated April 2023

Go to any twin mom club, Facebook group, or baby board, and the most commonly asked question by expectant twin moms is:

“How far along were you when you delivered and how long was your NICU stay?”

Your chances of preterm labor and delivery increase with each additional baby you are growing, as well as your type of twin pregnancy (mono/mono, mono/di, di/di).

Preterm labor is defined as delivery before 37 weeks and most doctors will not let a multiple birth go past 38 weeks. Nearly 60 percent of all twins, and more than 90 percent of triplets, are born prematurely (before 37 weeks). WHOA.

On average, twin pregnancies last 35 weeks, triplet pregnancies last 33 weeks and quad pregnancies last 29 weeks. Remember these are averages, so there are definitely MOMs out there that went all 40 weeks (or beyond 😮), and others that delivered earlier.

Most of this is out of your control, so there is no use in stressing over it. Just be sure to take care of yourself: lots of rest, fluids, and frequent healthy snacks.

The bottom line is: the earlier you deliver, (usually) the longer the NICU stay. Just as every pregnancy and delivery is different, every NICU stay is also a little different. There are babies born at 38 weeks that need NICU time, while others born at 35 weeks don’t stay in the NICU at all. So keep in mind these are just averages. A good rule of thumb is to expect to be in the NICU until your original due date.

And if you don’t have to, then you’ll be pleasantly surprised 🙂

Preterm Birth Milestones

I know some of this stuff is scary to read about, but this is life with multiples. Most people enjoy having this info, but if you’d rather not know (we understand!), skip over this section…

23 weeks is considered to be the age of viability; over half of the babies born at this time will survive past the NICU. These micro preemies will need help breathing and support to finish developing their body’s systems. They will most likely need to stay in the NICU for several months.
At 27 weeks babies are no longer micro preemies! They are now “very premature” and have a much higher rate of survival – 95%. Their eyelids are no longer fused and their lungs are more developed (although they still might need help breathing). They have developed the startle reflex and have coordinated sleep/awake cycles.
At 32 weeks babies are now “moderately preterm”. This week babies can mostly control their own body temperatures. They might still need help eating or breathing on their own, which are milestones required for NICU discharge. On average, babies born at 32 weeks will stay in the NICU for about a month. Making it to 32 weeks was my first “goal”, since babies born on or past this point have less chance of life-threatening complications. 32 week-ers have a 98% survival rate.
34 weeks was my next “goal”. Most doctors will not stop preterm labor at 34 weeks or later. These babies are in their final stages of lung development, and are fine-tuning the suck-swallow-breathe reflex needed for successful eating. This means that babies born at 34 weeks may not need much, or any, assistance breathing or eating.
At 36 weeks, “late preterm” babies might only need a little help growing and feeding. These babies may only be in the NICU for a few weeks, until they can maintain their body temperatures, master feeding and breathing simultaneously, and breathe on their own.

The NICU [pronounced NICK-you]:

Neonatal Intensive Care Unit

Now that you know the milestones, let’s talk about what to expect in the NICU.

Usually, no matter how you deliver (vaginally or via c-section), if the babies are preterm, your OB will likely first show them to you (Yay! Hi babies!), and then they will be whisked away to get checked out by the neonatal staff. The staff are usually in the delivery or an adjacent room, and if the babies don’t require oxygen or any kind of immediate help, once they are assessed, the neonatal staff will bring them back to you.

If they do need immediate intervention, your partner can go with the babies while your OB finishes up with you. Plan for who will go where ahead of time so you’re not stressing about it in the moment. Keep in mind that both babies may not have the same prognosis; many times, one baby will need to go to the NICU while the other can stay with mom.

For an uplifting and beautiful book that helps families navigate and document their NICU journeys, check out Our NICU Journey: Tiny Keepsake for Tiny Miracles. This book also serves as a lovely reminder to families with babies in the NICU that they are most definitely not alone.

NICU tips:

Depending on your condition, you may not be able to go see your babies right away in the NICU. Send your partner to keep you updated and informed.
The nurses are your best friends. Ask them all the questions you have and tell them your concerns. They will help you in every way possible and be your daily support system.
Be clear on your wishes. All of our doctors and nurses knew I was pumping; the girls were to have my breast milk first, and then formula if needed. We wanted to be there for every feeding so, if possible, they would wait for us to arrive.
Don’t forget to take care of yourself. The best gift we got in the hospital was a snack care package: almonds, cookies, granola bars and fruit. It got us (mostly me) through the few days we we had to camp out at the hospital. I needed to eat all the time to help build my breast milk supply. I also brought my HUGE water bottle from pregnancy with to make sure I stayed hydrated. The nurses were very insistent about making sure we slept. They encouraged us to get some rest even if it meant missing a feeding. They helped us realize that we needed to put our own “oxygen masks” on first before we could care for our babies.
The entire experience will probably be emotionally difficult. You might feel helpless and worried, but you will get through it.
NICU nurses sing, rock the babies, and comfort them when you are not there. It is important to remember your babies are being cared for while you are unable to be there.
Call the NICU as much as you want. You won’t be bothering them and they are happy to talk with you about how your baby is doing. You can even call when you are up pumping at 3 am.
Be prepared for separation: you from the babies, and the babies from each other.
Take care of yourself. Did I say this already? The NICU is hard. You have no control, you feel like you can’t help, and that you are useless as a parent. It was the most stressful, overwhelming, difficult time in my life. Not to mention your body is already whacked from all your hormones after giving birth. So give yourself a break; have a good cry and just remember that you can do this. If you are feeling too overwhelmed, talk to your doctor or the nurses. They are there to help you.
Don’t worry about anyone else. I was in no shape to be updating everyone on FB or via text. I called my mom when I could. She shared the information with my close family and friends. Don’t let anyone make you feel guilty. If your MIL or Grandma is upset because they want an update, then they need to reach out and be ready to wait for a response. If you say “no visitors”, they need to suck it up and respect that. The nurses are a great help here: if you don’t want to be the “bad guy”, they will tell your sister she can’t come in, or that the baby is sleeping, so no visitors. NICU’s usually won’t allow anyone in without a parent present, and have a strict limit of how many visitors can be there at one time. Special Nurseries may not allow visitors at all. Children are usually not allowed in the NICU, especially for the higher levels of care. Prepare for this if you have older children.
Finally, remember that this too shall pass. Though hard to believe when you’re going through it, your NICU stay is a small blip in your vast lifetime with your babies. There will come a day when you will all be home and back together again. Keep that perspective in mind.

Don’t stress, parents, you’ve got this!!
— the Lucie’s List team

Read a singleton mom’s NICU experience here.

Did you miss?

Recognizing Preeclampsia
Gestational Diabetes

About the Author

Marissa Bader is our Twins Editor and mental health writer, as well as the author of the children's book, The Only Me. She holds a BA in journalism and a MA in marriage and family therapy. Mama to twins girls and their singleton big sis, when she’s not kissing owies, playing dress-up, or mediating sister squabbles, Marissa enjoys dancing (you should see her get down when nobody’s watching!), and writing about topics pertaining to mental health, wellness, fitness and parenthood. Marissa lives in the frozen tundra, aka, Minneapolis, MN.

Multiple pregnancy: a modern view on the problem of managing pregnancy and childbirth (literature review) | Tsivtsivadze E.B., Novikova S.V.

The problem of the appearance of twins has been worrying the minds since the existence of mankind, has ethnic, cultural, social and economic implications. Traditions associated with the birth of twins have appeared in all ages. Hippocrates believed that twins were the result of the division of the seed into two parts, Democritus considered twins as the result of an excess of the seed, Aristotle explained the appearance of twins by the splitting of one germ into two. But even so far there is no unambiguous hypothesis explaining the formation of monozygotic twins.

The relevance of the problem of multiple pregnancy lies in a significant number of complications during pregnancy and childbirth, an increase in the proportion of cesarean section, postpartum complications, an increased level of antenatal losses at various gestational periods, and a high incidence of neurological disorders in surviving children [44].

Multiple pregnancies occur in 1.5–2.5% of cases, more often in families where the mother or father, or both spouses, were born as a result of a multiple pregnancy [1]. In this case, the genotype of the mother plays the most significant role. It is impossible not to recall the well-known formula, according to which multiple pregnancies occur with a frequency of geometric progression, which is formed when the number is raised to the power of 80: one twin occurs in 80 births, triplets - in 80 births in a square (6400), quadruple - in 80 births in a cube ( 512,000), five - for 80 births in the fourth degree (40 960,000).

The interest in multiple pregnancies that has existed since ancient times has increased in the last 15–20 years due to the avalanche-like increase in multiple pregnancies associated with the introduction of assisted reproductive technologies.

Patients with multiple pregnancies remain at a high risk of perinatal complications. Even with the modern development of medicine, perinatal mortality during twin pregnancy is 5 times higher than in singleton pregnancy, intrauterine fetal death is 4 times higher, neonatal - 6 times, perinatal - 10 times. The frequency of cerebral palsy in children from twins is 3-7 times higher, with triplets - 10 times. The level of ante- and intranatal complications on the part of the mother is 2-10 times higher than that in patients with singleton pregnancies [7, 14, 17, 19, 35, 40, 60].

Perinatal morbidity and mortality in twins depend on chorionicity. According to Sebire studies, the perinatal mortality rate, mainly due to severe prematurity at birth, is higher in monochorionic twins than in dichorionic twins (5 and 2%, respectively). The frequency of preterm birth up to 32 weeks. in monochorionic pregnancy is 10% compared to 5% in dichorionic twins. The frequency of spontaneous abortion in the period from the 11th to the 24th week. in dichorionic twins it is 2%, in monochorionic twins it is about 10% [1, 33, 50, 64, 65].

Interesting data were obtained by a group of authors who studied sex-associated differences in perinatal complications in 16,045 pregnant women with twins. Women with female twins have been found to have an increased risk of preeclampsia, but after birth, these twins had lower rates of neonatal and infant mortality, as well as a lower risk of respiratory disease than male twins [66].

Determination of zygosity before delivery is possible only when examining DNA in fetuses obtained as a result of amniocentesis, chorionic biopsy or cordocentesis. However, on the basis of zygosity, one cannot judge the type of placentation. Monozygotic twins can be either monochorionic or bichorionic [56].

Determination of the chorionicity of the fetuses is possible during an ultrasound scan, during which the number of placentas, the sex of the fetuses, and the presence of an amniotic septum are determined. The optimal time for the diagnosis of chorionicity is 6–9 weeks. pregnancy. In the presence of dichorionic twins, two fetal eggs are determined, separated by a thickened septum of 2 mm or more. The use of this criterion makes it possible to diagnose mono- and bichorionic twins with an accuracy of up to 85% and 92.3%, respectively [71].

Multiple pregnancy may be complicated by growth retardation of one or both fetuses, feto-fetal transfusion syndrome (FFTS), intrauterine death of one or both fetuses.

FFTS, first described by Schatz in 1982, occurs in 1 out of 5 monochorionic twins [47, 48]. Its morphological substrate is the anastomosing vessels between the two fetal circulatory systems [28]. This is a specific complication for monozygotic twins with a monochorionic type of placentation. Of particular difficulty are monochorionic monoamniotic twins, when pregnancy is complicated not only by FTTS, but also by problems with the umbilical cords of the fetuses (Fig. 1).

The criteria for FFTS are an intra-pair difference in weight of more than 20% and different concentrations of hemoglobin in fetuses [23]. For many years, the diagnosis of TTTS was established retrospectively in the neonatal period. Based on the data of ultrasound diagnostics, FFTS criteria were developed, which are used in practice to determine the management of pregnancy [63].

The most common factor associated with ante- and neonatal mortality and morbidity in twin pregnancies is low birth weight. In the vast majority of cases, low body weight of children is due to preterm birth. Various hypotheses of threatened miscarriage in multiple pregnancies are discussed in the literature. According to one of them (premature birth is a natural consequence of twin pregnancy), the main cause of premature development of labor is the overstretching of the muscle fibers of the uterus, the release of prostaglandins and reduced uteroplacental blood flow. Another hypothesis is based on the data of the Joint Perinatology Project [4], indicating that infection of the amniotic membranes contributes to their premature rupture, which most often leads to preterm birth.

A systematic review of randomized controlled trials evaluating the efficacy of antenatal screening for lower genital tract infections and their treatment in reducing preterm birth and associated morbidity demonstrated the high efficacy of such screening programs. Thus, in the intervention group (2058 women) screening and treatment of bacterial vaginosis, trichomoniasis and candidiasis were performed, in the control group (2097 women) were not screened, they were examined only in the presence of complaints or clinical manifestations. Preterm birth before 37 weeks. were observed significantly less frequently in the intervention group (3% vs. 5% in the control group) with a relative risk (BP) of 0.55 (95% CI 0.41 to 0.75). The frequency of birth of children with low body weight (weighing 2500 g or less) was 52% lower in the intervention group (BP 0. 48, 95% CI 0.34 to 0.66), and very low birth weight children (weighing 1500 g or less) - 6% lower in the intervention group than in the control group (BP 0.34, 95% CI 0.15 to 0.75) [53].

Thus, there is high-certainty evidence that screening and treatment programs for vaginal infections in pregnant women reduce preterm and low birth weight preterm births.

The high-risk group for complications during pregnancy and perinatal outcomes should include women with congenital anomalies in the development of the uterus. The results of numerous studies have shown that the outcome of pregnancy is largely due to the nature and severity of the malformation of the uterus. Relatively favorable outcomes were observed with a saddle uterus, unfavorable - with a bicornuate uterus and intrauterine septum [2, 9, 11, 38]. So, in the literature available to us, only 7 cases of multiple pregnancy in a bicornuate uterus were found. A. Bongain et al. (1994) suggest that the possibility of fertilization of two eggs in a pregnant woman with a congenital anomaly of the uterus (bicornuate, complete doubling) is 1:1,000,000.

Based on the foregoing, our clinical case of multiple pregnancy with complete duplication of the uterus is of scientific and practical interest.

Pregnant S., 1988 years of age, was observed under the conditions of MONIIAG in 2010 due to the presence of an anomaly in the development of the genitourinary system - complete doubling of the uterus and pregnancy with twins. The pregnancy proceeded with the phenomena of the threat of termination, for which inpatient treatment was repeatedly carried out. On December 28, 2010, emergency delivery was performed at a gestational age of 35 weeks. due to premature rupture of amniotic fluid. A Pfannenstiel transection was performed, caesarean sections were performed in the lower uterine segments of both uterus with Derfler incisions (Fig. 2). The children were born weighing 2320 and 2000, are currently healthy.

Neurological complications are a significant problem in multiple pregnancies [6, 44]. The greatest number of neurological complications is observed in premature babies and in children with malnutrition, as well as in the presence of FTTS.

Stillbirth and neonatal mortality in multiple pregnancies are recorded 3 times more often than in singleton pregnancies, and are respectively 14.9 and 19.8 per 1000 live births. The financial costs of providing medical care to each child from twins with multiple pregnancies during the first 5 years of life are 2 times higher than those for children born with a single pregnancy.

Prematurity is considered as the main cause of neonatal mortality in multiple pregnancies. Preterm birth is the leading cause of neonatal death, as well as early and delayed disability. The rate of preterm birth varies from 6% to 12% in developed countries, and this figure is usually higher in developing countries. About 40% of all preterm births occur before 34 weeks. and 20% - up to 32 weeks. The contribution of these preterm births to the total perinatal morbidity and mortality is more than 50% [38, 46].

Despite a significant arsenal of tocolytic agents, the frequency of preterm birth in the world is not decreasing, and the decrease in perinatal mortality is mainly due to the success of neonatologists in nursing premature babies. In connection with the foregoing, the tactics of managing and treating the threat of preterm labor should take into account the possible causes of their development, and not consist only in the appointment of symptomatic agents aimed at reducing the contractile activity of the uterus.

At present, some progress has been made in the treatment of threatened preterm labor due to drugs that suppress the contractile activity of the uterus.

In practical obstetrics, magnesium sulfate is often used. The mechanism of action of Mg2+ ions on smooth muscles has not been finally established. An important aspect of the use of magnesium sulfate in obstetric practice is the presence of an anticonvulsant effect in the drug, which allows it to be used to treat preeclampsia and eclampsia. With the threat of preterm birth, the prophylactic use of magnesium sulfate as a monotherapy has a less pronounced effect.

There is evidence of a relationship between the use of magnesium sulfate in the prenatal period in preterm labor or preeclampsia and a subsequent decrease in the risk of developing cerebral palsy in premature newborns with low birth weight. It should be emphasized that a neuroprotective effect was demonstrated for low total doses of magnesium sulfate (4 and 12 g), while for high total doses (>30 g) a toxic effect was demonstrated, which was accompanied by an increase in infant mortality. Incidence statistics were assessed using electronic databases and journal publications [25].

The Committee on Obstetrics of the American College of Obstetricians and Gynecologists (ACOG, March 2010), based on multicenter data on the neuroprotective effect of magnesium sulfate and the reduction in the incidence of cerebral palsy in preterm infants, recommends that the use of this drug be added to protocols for impending PR <30 weeks: bolus 4-6 g of magnesium sulfate, then infusion of 1-2 g/h for 12 hours [27, 32, 33].

In recent decades, both foreign and domestic researchers have accumulated considerable experience in the use of calcium channel blockers in obstetric practice, primarily in diseases accompanied by an increase in blood pressure. However, the use of calcium channel blockers as tocolytic agents in case of threatened miscarriage is often accompanied by undesirable effects. It should also be remembered that in Russia nifedipine is not registered as a tocolytic agent, therefore, before using it, it is necessary to obtain the written informed consent of the patient for its use [10, 22, 55].

As you know, the decisive role in the regulation of the contractile function of the uterus during childbirth is assigned to biologically active substances of a lipid nature - prostaglandins (especially PGF2a). The tocolytic effect of prostaglandin synthesis inhibitors has been proven experimentally and as a result of clinical observations. However, without selective properties, prostaglandin synthesis inhibitors cause undesirable effects on the fetus and newborn. The most severe complications are manifested in premature closure of the arterial duct and a pronounced increase in pulmonary arterial pressure [59, 71].

Progesterone, although not a tocolytic in the true sense of the word, is increasingly being used in the protocols of tocolytic therapy for preterm birth. There is no effective way to prevent preterm birth during twin pregnancy. At the same time, three large randomized trials have demonstrated that progesterone is effective in preventing preterm birth in high-risk singleton pregnancies. In recent years, the main (primarily immune) mechanisms for the implementation by gestagens of their protective function in relation to the fetus have been revealed [19, 35, 40, 74].

In patients belonging to the high-risk group (history of preterm birth or shortening of the cervix), the use of progesterone in the prenatal period led to a decrease in the frequency of early termination of pregnancy by 35% [28, 30, 52, 53, 63, 68].

It is noteworthy that the reduction in the incidence of preterm birth with the use of progesterone is not accompanied by a significant improvement in neonatal outcomes and a decrease in perinatal mortality. However, antenatal use of progesterone in singleton pregnancies has been found to be associated with a reduced risk of neonatal sepsis.

British experts conducted a study to evaluate the value of progesterone in the prevention of preterm birth in twins (STOPPIT - STudy Of Progesterone for the Prevention of Preterm Birth In Twins). It was concluded that the use of progesterone in twins does not reduce the incidence of preterm birth or intrauterine fetal death up to 34 weeks. pregnancy [21]. Perhaps this is due to the insufficient dosage of progesterone preparations [3].

Differences in the biological effectiveness of progesterone in multiple and singleton pregnancies should be the subject of further research. According to the authors, such differences are associated with the predominance in the pathogenesis of preterm labor with twin overstretching of muscle fibers, while in singleton pregnancy, infectious and inflammatory processes play the main role [58].

When prescribing progesterone preparations, the informed consent of the woman is required, since the manufacturing companies, when registering these medicines in the Russian Federation, in the indications for the use of progesterone do not indicate threatening preterm labor and the possibility of using the drugs in the second and third trimesters of pregnancy.

In recent years, in Russia, the most common and frequently used drug from the group of β-mimetic agents is hexoprenaline, a selective β2-sympathomimetic that relaxes the muscles of the uterus. However, according to the results of systematic reviews of randomized controlled trials, the effect of tocolytics alone on reducing the incidence of preterm birth has not been proven. The main goal of prescribing tocolysis is to delay delivery by 48 hours in order to transport the pregnant woman to the perinatal center and conduct a full course of antenatal steroids [31, 43, 56, 73].

Risk of preterm birth: diagnostic criteria

Diagnosis of preterm labor is associated with certain difficulties, since there are no specific symptoms. The diagnosis of the onset of preterm labor can be clarified using transvaginal ultrasound with the measurement of the length of the cervix or the determination of fetal fibronectin in the cervico-vaginal secret [1, 70].

In 2010, Conde-Agudelo et al. summarized the available data on the accuracy of predicting spontaneous preterm birth in twins by measuring the length of the cervix. They conducted a systematic review and meta-analysis of 21 non-randomized studies (16 studies of pregnant women with clinical signs of possible preterm birth and 5 studies of pregnant women without symptoms of threatened miscarriage, a total of 3523 women). It was concluded that vaginal echocervicometry is a good diagnostic criterion for spontaneous preterm birth in the absence of clinical symptoms in pregnant women with twins at 20–24 weeks of gestation. [26].

In twin pregnancy, suturing the shortened cervix increases the risk of preterm birth [17].

At the same time, a number of authors describe the positive experience of applying U-shaped and circular sutures, which contribute to the prolongation of pregnancy until the birth of viable children with twins, triplets and even quadruplets [42].

In order to determine the risk of preterm birth, available express test systems are used to determine phosphorylated protein-1 that binds insulin-like growth factor (PSIFR-1) in cervical secretion [12]. These methods increase diagnostic accuracy and reduce the risk of iatrogenic complications, as they prevent overdiagnosis of preterm labor.

Two indicators are important for the diagnosis of active preterm labor: regular contractions and dynamic changes in the cervix. The degree of cervical dilation is an indicator of the prognosis of the effectiveness of tocolysis. If the opening of the pharynx is more than 3 cm, tocolysis is likely to be ineffective. Changes in the cervix are a more objective indicator than the assessment of labor activity. With a cervical length of more than 3 cm, the probability of labor onset within the next week is about 1%, which does not require hospitalization of the patient [48].

The algorithm of actions of a doctor in case of a threat of preterm birth depends on the clinical picture, gestational age, integrity of the membranes and consists of the following main areas: risk assessment of preterm birth, prevention of RDS of the newborn, prolongation of pregnancy to transfer the mother to the perinatal center, prevention and treatment of infectious complications, in including with premature rupture of the membranes.

At present, the most accurate marker of preterm labor should be considered the detection of fibronectin in the cervico-vaginal secretion at gestational age up to 35 weeks, which indicates an increased risk of preterm labor, especially within 2 weeks. since the test. It is very important for clinical practice that this test has a high predictive value of a negative result - in the absence of fibronectin in the vaginal secretion, the probability that a woman will give birth within 1 week is about 1% [37].

Prescription of antenatal steroids significantly reduces morbidity and mortality in children from RDS, IVH, NEC, and patent ductus arteriosus.

Roberts et al. in a recent meta-analysis of 21 randomized trials, a single antenatal course of steroids (betamethasone 24 mg or dexamethasone 24 mg over 48 hours) significantly reduced neonatal mortality by 31%, RDS by 34%, and early sepsis within the first 48 hours life - by 44% and the need for artificial lung ventilation - by 20%. A repeated antenatal course of corticosteroids may be useful in the case when more than 7 days have passed from the previous course and symptoms of threatened preterm labor continue or reappear.

Laswell et al. in 2010, conducted a meta-analysis of 41 publications that examined neonatal mortality among infants weighing <1500 g or <32 weeks gestation in perinatal centers compared with infants born in lower-level medical facilities. The results of the meta-analysis showed that timely transportation of a pregnant woman with a high risk of preterm birth to a perinatal center is an event that significantly increases the chances of survival of a premature baby.

Antibiotic therapy for premature rupture of membranes

The effect of prescribing antibiotics in reducing the incidence of chorioamnionitis and neonatal morbidity in cases of premature rupture of membranes has been confirmed in qualitative studies.

A systematic review of 22 randomized controlled trials showed that the use of antibiotics for preterm rupture of membranes and preterm pregnancy significantly reduces the incidence of chorioamnionitis and the number of children born within 48 hours after rupture of the membranes. In addition, the use of antibiotics in this clinical situation can reduce the incidence of neonatal infection, the need for surfactants, the use of oxygen therapy in the newborn, and the incidence of pathological symptoms in neurosonography.

All of the above suggests that those carrying multiple pregnancies are a special contingent that needs careful monitoring at all stages of pregnancy.

It is necessary to say a few words about childbirth. Undoubtedly, this group of pregnant women represents women whose caesarean section rate is much higher than in the population [13].

According to MONIIAG, in spontaneous multiple pregnancies, the percentage of spontaneous births and caesarean sections is 46.4 and 44.9, respectively.%. Delivery operations used at the birth of the second fetus account for 8.7%. Nevertheless, we do not deny the possibility of conducting childbirth through the natural birth canal. It should be noted that the course of the second stage of labor with twins is often unpredictable and uncontrollable, and much is determined by the skill of the obstetrician-gynecologist. If the doctor has the necessary skill, then both the application of a vacuum extractor to the head of the second fetus and the extraction of the second fetus by the pelvic end will be common obstetric operations that do not affect the child's condition at birth and during the period of neonatal adaptation.

As for multiple pregnancies that occurred as a result of IVF, in many obstetric institutions, planned abdominal delivery is performed. Under the conditions of MORIAH, 30% of pregnant women with multiple pregnancies resulting from IVF were delivered through the natural birth canal.

It should be emphasized that in general there can be no standards in obstetrics, and clinical success is possible only with an individual, balanced and thoughtful medical approach.

Thus, patients with multiple pregnancies constitute a high-risk group for the development of maternal and perinatal complications. This is directly related to the fact that, evolutionarily, the body of a pregnant woman is adapted for bearing one fetus.

The key to the success of carrying multiple pregnancies and nursing newborns should be continuity in the activities of all obstetric and gynecological departments and departments of newborns. And, of course, further in-depth study of this problem should be aimed at reducing perinatal losses and maintaining the reproductive health of women.

Literature

Development of twins by week of pregnancy

Pregnancy

Article

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According to various estimates, there are 70-80 million pairs of twins in the world today. At the same time, multiple pregnancy is becoming more common. Researchers name different reasons for multiple pregnancy: heredity, modern methods of infertility treatment, in particular IVF, the increased average age of women in labor. One way or another, pregnancy with twins is a very exciting and wonderful period that requires special attention.

6 min. for reading Feb. 17, 2022

Pregnancy with twins: signs and features of the course

The signs of twins are not much different from the symptoms of a singleton pregnancy. The essence of the differences is in the intensity and earlier period of these manifestations.

Early toxicosis is one of the most common signs of multiple pregnancy. Nausea, vomiting, odor intolerance, drowsiness and dizziness can disturb the expectant mother from the first days of the birth of babies. Symptoms stop at 12-15 weeks.
Accelerated weight gain and belly growth — during pregnancy with twins, a woman rapidly gains from 15 to 15 kg, and only 8 kg with one fetus.
Frequent urination - the uterus grows faster and already in the early stages presses on the bladder, provoking frequent urination. In addition, filling the abdominal cavity, the enlarged uterus makes it difficult for the outflow of bile and raises the diaphragm. This causes bitterness in the mouth and shortness of breath, two more signs of twin pregnancy.
Movements of two babies are much more intense and grow faster.

Read also: Multiple pregnancy: 7 signs

Multiple pregnancy requires great care from future parents and doctors. With the development of two babies, the risk of miscarriage and premature birth increases, and the load on the mother's body also increases significantly.

Rapid and strong weight gain often adversely affects the condition of blood vessels, spine and joints. As a result - back pain, swelling of the legs and varicose veins.

An enlarged uterus puts more pressure on the internal organs in the abdominal cavity. Therefore, mothers of twins are more often annoyed by constipation and heartburn. Also, a large amount of fluid in the body increases the risk of anemia.

See also: Anemia during pregnancy

Childbirth in multiple pregnancies occurs several weeks earlier: most often at 36-38 weeks, but the probability of even earlier births must be taken into account. In addition, most twins are born by caesarean section, as there is an increased risk of complications during vaginal delivery.

Interesting

Twins have a special advantage: babies quickly adapt to a new environment, grow and gain weight at an accelerated pace, so they easily catch up with their peers.

Types of multiple pregnancies

There are two main types of twins:

Identical, or identical - appear when the fetal egg divides into several cells, most often two. As a rule, identical twins are of the same sex, have the same set of genes, blood type and Rh factor, and are almost indistinguishable in appearance.
Fraternal twins develop from two fertilized eggs. They have separate fetal sacs and different placentas. They can be of different sexes and resemble each other no more than ordinary brothers and sisters. This type of multiple pregnancy is much more common.

Interesting

Colloquially, fraternal twins are called twins. But from a scientific point of view, this is not true, because such a term does not exist.

Pregnancy with twins by weeks

First trimester

5-6 weeks. It is already possible with a high probability to identify twins, but only through ultrasound.

See also: 1st trimester screening: what is it and how is it done?

8 weeks. A multiple pregnancy can be diagnosed by a gynecologist during examination. But this method of definition is not very accurate. This week, the placenta is strengthening, the fetuses already have the rudiments of all organs and the neural tube. On an ultrasound of twins, you can see how the hearts contract.
10 weeks. The size of both babies reaches 4.5 cm, all organs and systems are actively formed.
11 weeks. The expectant mother has a tummy and the symptoms of toxicosis gradually subside.
12 weeks. The twins have grown to 6 cm and fixed on the wall of the uterus, so the likelihood of a miscarriage has decreased significantly.

II trimester

13 weeks. The weight of the twins is growing more and more actively every week, now it is about 14 g. At the same time, the uterus increases dramatically, sometimes causing pain in the lumbar region.
14 weeks. The uterus is growing rapidly and is already much taller than in a singleton pregnancy.
15 weeks. The twins have already gained about 60 g and have grown to 10 cm. They train breathing movements and suck their fingers.
16 weeks. The belly of the mother of twins looks like she is at 18 weeks of a singleton pregnancy. The crumbs are already moving, but the tremors are still weak and not felt.
17 weeks. The stomach has become large, it interferes with sleep. Now is the time to take intensive care of your skin to avoid stretch marks.
18 weeks. The abdomen is enlarged. To reduce stress on your back, wear a brace. If the pregnancy is the second, the first movements are already noticeable. It is possible to increase the tone of the uterus.
19 weeks. Babies grow “by leaps and bounds”: they have stretched up to 25 cm and have already gained almost 300 g each. The nervous system and lungs are actively forming, a reaction to bright light appears, the crumbs begin to feel the presence of each other.
20 weeks. The mother-to-be feels the twins for the first time, and their bond grows stronger. Children form their own schedule of periods of sleep and activity. Kidneys worked.
21 weeks. Babies are great at hearing and recognizing sounds. They have learned to open their eyes, but their eyesight is still very weak. The bones have become stronger, the coordination of movements has improved.
22 weeks. The time of the planned ultrasound, during which it may turn out that the children differ in height and weight. If the difference is insignificant, there is nothing to worry about.

Read also: 2nd trimester screening: when to do it?

23 weeks. Babies are actively gaining weight and have already “ate” 500 g. During this period, it is important for mom to monitor nutrition and seriously take care of her health.
24 weeks. The weight has increased even more. Be attentive to your feelings: the risk of pyelonephritis, preeclampsia or placenta previa has increased.
25 weeks. The belly and the twins inside grow equally fast. It's time to focus on the health of the kids and think about maternity leave.
26 weeks. The uterus filled the abdominal cavity, squeezing the intestines, causing labored breathing and frequent urination.
27 weeks. The weight of the twins is approaching 1 kg. Increased risk of amniotic fluid leakage and preterm birth.
28 weeks. Babies weigh more than 1 kg and are quite viable. It's time to go on maternity leave.

III trimester

29 weeks. The twins stock up on fat and prepare to meet the outside world. Weight reaches 1100–1300 g.
30 weeks. Growth stops a little, but weight gain is becoming more and more active. Babies take their final position in the uterus. If they are positioned incorrectly, this may be an indication for a caesarean section. The twins can already breathe on their own, regulate their body temperature, and the intestines are quite ready for eating.
31 weeks. The abdomen has grown to its maximum size. The movements of the twins became intense, up to pain. During this period, it is desirable to be more outdoors.

See also: How much weight can I put on?