Introductory Chapter: About Multiple Pregnancies

*Hassan S. Abduljabbar*

#### **1. Introduction**

Twins are the commonest type of multiple pregnancies. It means that two offspring created by the same pregnancy can be identical and become (monozygotic). Twins usually develop from one zygote, which splits and forms two embryos, non-identical or (dizygotic), meaning that each twin sets from separate oocytes, fertilized by different sperm [1]. One in 250 natural pregnancies will result by chance in twins [2].

#### **2. Types of twins**

The first type is when two separate oocytes are fertilized by two different sperm. This is non-identical or (dizygotic twins), but the result of if one oocyte fertilized, this is identical twins (monozygotic). Rare type is conjoined twins. There are rare (unique) twins, mirror twins, conjoined twins (physically connected.), parasitic twins, semi-identical twins, and female and male identical twins [3].

#### **3. The risk factors**

Genetics, diet, previous pregnancies, and use of fertility drugs are risk factors for multiple pregnancies and raise the chances of having twins. Age is another essential factor, especially ages over 35 have a greater chance of multiple pregnancies. High parity and race are risk factors [4]. Igbo-Ora, southwestern Nigeria, Twin Capital of the World, has a large number of twin pregnancies. In Igbo-Ora, research has suggested that this is most likely related to the women's eating habits in the area [5, 6]. Research has found no direct relationship between dietary intake and multiple pregnancies but has proven that a widely consumed tuber (yams) could be responsible [6, 7].

#### **4. Multiple pregnancies are increasing**

There has been about a 10-fold rise in twinning rates over the past two decades [8]. Around 30–50% of all twin pregnancies result from infertility treatments. The incidence of twins increased in the last four decades in developed countries. As women delayed childbearing and the age of the first pregnancy became late became an important factor, and wild use of medication for induction of ovulation and IVF increased the probability of multiple births [9].

#### **5. Vanishing twin syndrome**

About 10–15% of singleton births start as twins, and often, one is lost in the early pregnancy; this is called vanishing twin syndrome. In 1945, vanishing twin syndrome was first recognized [10, 11].

#### **6. Cryptophasia**

According to what is (published in the Journal Institute of General Linguistics), there are bizarre phenomena that twins can speak a unique language only they can understand. But it disappears with time as the twins grow and learn other languages [12].

#### **7. Time of delivery**

The percentage of twins that can make it to 37 weeks' gestation is 49%, and 6% are preterm [13]. Care is required during the antenatal period twin pregnancy is more susceptible to anemia; thus, they need extra care for their health and different prenatal vitamins. Women pregnant with twins should take the same prenatal vitamins for any pregnancy, but recommending extra folic acid and iron. The additional folic acid and excess iron will help ward off iron-deficiency anemia, which is more common when pregnant with multiple pregnancies [14].

The meaning of twin, A, and B The twin developing closest to the cervix is called Baby A, and the other is called baby B [15].

#### **8. ART and Multiple pregnancies**

Multiple pregnancies are now more common as a result of fertility treatments [16]. In vitro fertilization (IVF) might cause multiple pregnancies due to more than one embryo transfer [17]. Induction of ovulation non-ART fertility treatments stimulates the development of multiple oocytes, which cannot be controlled, and may lead to multiple pregnancies [18].

We know that some infertility patients prefer to have twins. Still, as a fact, all multiple pregnancies have higher risks for both infant and mother [19]. It has been shown that in the last four decades, multiple pregnancies steadily increased, and twins nearly doubled [20]. The increasing trend of multiple pregnancies coincides with the introduction of fertility treatment [21]. After considering maternal age, more than one-third of twins and more than three-quarters of triplets and higher-order multiples resulted from conception assisted by fertility treatments [22]. Improving the practice of ART results in a decrease in multiple pregnancies due to fewer embryos being transferred during ART [23].

The maximum number of embryo transfers should not be more than four in women above the age of 39 years. In those older women with high-quality embryos, no more than three embryos should be transferred. If four embryos are transferred, the data suggest that the transfer of four or more embryos has a positive effect: increasing the pregnancy rates without significantly impacting the multiple pregnancy rates. This effect is only seen in women aged <45. Transferring three embryos *Introductory Chapter: About Multiple Pregnancies DOI: http://dx.doi.org/10.5772/intechopen.108518*

may increase the chance of multiple pregnancies without increasing the overall pregnancy rate. The maximum number of embryo transfers should not be more than three embryos [24].

Fertility treatments can cause twins to have a higher risk of congenital disabilities than singletons; it questions the notion that fertility treatments contribute to those abnormalities [25]. The implantation of two fertilized oocytes leads to twins, and requesting to transfer more than one embryo may increase the chance of multiple pregnancies [26].

#### **9. There are risks associated with IVF twins**

#### **9.1 Preeclampsia**

It is one of the complications of multiple pregnancies edema, high blood pressure, and proteinuria. Premature labor is a significant and common complication of multiple pregnancies. Statistically, about 60% of twins are born before their due date [27]. The risk is about three times more than in the case of normal twin pregnancies [28].

#### **9.2 Twin-twin transfusion syndrome (TTTS)**

Another thing you should remember when it comes to twins with IVF is the risk of TTTS. When two identical twins share the placenta, the possibility of twin-twin transfusion can occur at about 5%. Life-threatening conditions might happen if one of the babies had more blood than the other twins [29].

#### **9.3 Intrauterine growth restriction (IUGR)**

IUGR is a complication that might occur in multiple pregnancies. It means that one of the babies is not developing at the pace it should. Due to this delayed growth, several health implications are imminent for either or both babies [30].

#### **9.4 Cesarean section**

Carrying twins might also mean that a cesarean section might be the method of delivering twins having a higher incidence of cesarean section. Compared with vaginal birth, recovering from a cesarean section requires more time, and looking after two babies after a cesarean section can be very difficult [19]. Low birth weight and premature delivery, depending on the time of the delivery, heart problems, problems with breathing, hearing, vision, and cerebral palsy are all issues that may occur [31].

#### **10. Conclusion**

Multiple pregnancies have high maternal and neonatal complications, especially preterm delivery, which increases the risk of significant neonatal morbidity and mortality. Promotion of the elective single embryo transfer strategy is needed to reduce multiple pregnancies following IVF technologies.

#### **Disclosure**

I state that this introduction has not been previously published, nor being considered for publication elsewhere. No conflict of interest.

## **Author details**

Hassan S. Abduljabbar Dr. Erfan and Bagedo General Hospital and Jeddah Fertility Center, Jeddah, Saudi Arabia

\*Address all correspondence to: profaj17@yahoo.com

© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Introductory Chapter: About Multiple Pregnancies DOI: http://dx.doi.org/10.5772/intechopen.108518*

#### **References**

[1] Beck JJ, Bruins S, Mbarek H, Davies GE, Boomsma DI. Biology and genetics of dizygotic and monozygotic twinning. In: Twin and Higher-Order Pregnancies. Cham: Springer; 2021. pp. 31-50

[2] Vitthala S, Gelbaya TA, Brison DR, Fitzgerald CT, Nardo LG. The risk of monozygotic twins after assisted reproductive technology: A systematic review and meta-analysis. Human Reproduction Update. 2009;**15**(1):45-55

[3] Umstad MP, Calais-Ferreira L, Scurrah KJ, Hall JG, Craig JM. Twins and twinning. Emery and Rimoin's Principles and Practice of Medical Genetics and Genomics. 2019;**3**:387-414

[4] Bhalotra S, Clarke D. Twin birth and maternal condition. Review of Economics and Statistics. 2019;**101**(5):853-864

[5] Tambiah SJ. Transnational movements, diaspora, and multiple modernities. In: Multiple Modernities. Vol. 1. Routledge; 29 Sep 2017. pp. 163- 194. Available from: taylorfrancis.com

[6] Akinseye K, Anifowoshe A, Owolodun O, Aina O, Iyiola O. Frequency of twinning in Nigeria. A review. Manila Journal of Science. 2019;**12**:78-88

[7] Hotz C, Loechl C, de Brauw A, Eozenou P, Gilligan D, Moursi M, et al. A large-scale intervention to introduce orange sweet potato in rural Mozambique increases vitamin a intakes among children and women. British Journal of Nutrition. 2012;**108**(1):163-176

[8] Sobek A, Prochazka M, Klaskova E, Lubusky M, Pilka R. High incidence of monozygotic twinning in infertility treatment. Biomedical Papers. 2016;**160**(3):358-362

[9] Martin JA, Hamilton BE, Osterman MJ. Three decades of twin births in the United States, 1980-2009. NCHS Data Brief. Jan 2012;(80):1-8. PMID: 22617378

[10] Shelke PS, Jagtap PN. Twin pregnancy a complicating journey for both mothers and babies: Elaborate review. International Journal of Basic & Clinical Pharmacology. Mar 2020;**9**(4):674. DOI: 10.18203/ 2319-2003.ijbcp20201196

[11] Bókkon I, Vas JP, Császár N, Lukács T. Challenges to free will: Transgenerational epigenetic information, unconscious processes, and vanishing twin syndrome. Reviews in the Neurosciences. 2014;**25**(1):163-175

[12] Mogford K. development in twins. Language Development in Exceptional Circumstances. 2013:80

[13] Park SH, Lim DO. Distribution and definition of degree for inter twin birth weight discordance. Journal of Health Informatics and Statistics. 2019;**44**(3):286-291

[14] Bricker L. Optimal antenatal care for twin and triplet pregnancy: The evidence base. Best Practice & Research Clinical Obstetrics & Gynaecology. 2014;**28**(2):305-317

[15] Melka S, Miller J, Fox NS. Labor and delivery of twin pregnancies. Obstetrics and Gynecology Clinics. 2017;**44**(4):645-654

[16] Black M, Bhattacharya S. Epidemiology of multiple pregnancy and the effect of assisted conception. In: Seminars in Fetal and Neonatal Medicine. Vol. 15, No. 6. WB Saunders; 2010. pp. 306-312

[17] Adamson GD, Norman RJ. Why are multiple pregnancy rates and single embryo transfer rates so different globally, and what do we do about it? Fertility and Sterility. 2020;**114**(4):680-689

[18] Diamond MP, Mitwally M, Casper R, Ager J, Legro RS, Brzyski R, et al. Estimating rates of multiple gestation pregnancies: Sample size calculation from the assessment of multiple intrauterine gestations from ovarian stimulation (AMIGOS) trial. Contemporary Clinical Trials. 2011;**32**(6):902-908

[19] Young BC, Wylie BJ. Effects of twin gestation on maternal morbidity. In: Seminars in Perinatology. Vol. 36, No. 3. WB Saunders; 2012. pp. 162-168

[20] Chauhan SP, Scardo JA, Hayes E, Abuhamad AZ, Berghella V. Twins: Prevalence, problems, and preterm births. American journal of Obstetrics and Gynecology. 2010;**203**(4):305-315

[21] Fauser BC. Medical approaches to ovarian stimulation for infertility. In: Yen and Jaffe's Reproductive Endocrinology. Elsevier; 2019. pp. 743-778

[22] Pison G, Monden C, Smits J. Twinning rates in developed countries: Trends and explanations. Population and Development Review. 2015;**41**(4):629-649

[23] Kissin DM, Kulkarni AD, Mneimneh A, Warner L, Boulet SL, Crawford S, et al. Embryo transfer practices and multiple births resulting from assisted reproductive technology: An opportunity for prevention. Fertility and Sterility. 2015;**103**(4):954-961

[24] Pandian Z, Marjoribanks J, Ozturk O, Serour G, Bhattacharya S. Number

of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection. Cochrane Database of Systematic Reviews. 2013;(7):25

[25] Wen SW, Miao Q, Taljaard M, Lougheed J, Gaudet L, Davies M, et al. Associations of assisted reproductive technology and twin pregnancy with risk of congenital heart defects. JAMA Pediatrics. 2020;**174**(5):446-454

[26] Knopman JM, Krey LC, Oh C, Lee J, McCaffrey C, Noyes N. What makes them split? Identifying risk factors that lead to monozygotic twins after in vitro fertilization. Fertility and Sterility. 2014;**102**(1):82-89

[27] Phipps EA, Thadhani R, Benzing T, Karumanchi SA. Pre-eclampsia: Pathogenesis, novel diagnostics and therapies. Nature Reviews Nephrology. 2019;**15**(5): 275-289

[28] Vogel JP, Chawanpaiboon S, Moller AB, Watananirun K, Bonet M, Lumbiganon P. The global epidemiology of preterm birth. Best Practice & Research Clinical Obstetrics &Gynaecolog. 2018;**52**:3-12

[29] Simpson LL, Society for Maternal-Fetal Medicine (SMFM). Twin-twin transfusion syndrome. American journal of Obstetrics and Gynecology. 2013;**208**(1):3-18

[30] Valsky DV, Eixarch E, Martinez JM, Crispi F, Gratacós E. Selective intrauterine growth restriction in monochorionic twins: Pathophysiology, diagnostic approach and management dilemmas. In: Seminars in Fetal and Neonatal Medicine. Vol. 15, No. 6. WB Saunders; 2010. pp. 342-348

*Introductory Chapter: About Multiple Pregnancies DOI: http://dx.doi.org/10.5772/intechopen.108518*

[31] Barzilay E, Mazaki-Tovi S, Amikam U, de Castro H, Haas J, Mazkereth R, et al. Mode of delivery of twin gestation with very low birthweight: Is vaginal delivery safe? American Journal of Obstetrics and Gynecology. 2015;**213**(2):219-2e1

#### **Chapter 2**
