New medical risks affecting obstetrics after implementation of the two-child policy in China

Abstract

China recently instituted a two-child policy in response to its aging population, declining workforce and demographic dividend, and the need to develop asocial economy. Additionally, women generally delay having a second child because of the overwhelming pressure in their lives. With the improvements in assisted fertility technologies in recent years, the number of elderly women attempting to bear children has increased. The quality of woman’s eggs and a man’s sperm declined dramatically with increasing age, leading to an increased risk of pregnancy-related complications among older women. Therefore, the types of fertility problems experienced by elderly females must be provided with considerable attention by obstetricians. This commentary article focuses on the medical problems faced by older second-child pregnant women. This work discusses their increased rates of infertility, spontaneous abortion, fetal malformation, gestational diabetes, cesarean section, placenta previa, postpartum hemorrhage, postpartum depression, and hypertensive disorders, which complicate pregnancy.

Keywords

two-child policy / birth defects / cesarean delivery / placenta previa

Introduction

The number of two-child families may substantially increase because of the change in the family planning policy of the Chinese government in 2015. This increase will create new challenges in the field of obstetrics, and methods for dealing with these challenges should be urgently explored [1]. According to the family planning policy announced by the China Central Committee of the Communist Party two years ago, couples will be allowed to have two children if one of the parents is an only child. Currently, many families with only one child are planning to have a second child, which will result in a significant increase in the proportion of elderly parturient women. These elderly women are not only likely to be afflicted with genetic diseases but also develop complications during pregnancy, such as pregnancy-related metabolic disorders and gestational hypertension disease. Furthermore, the risks for a scarred uterus, placenta previa, postpartum hemorrhage, and uterine rupture are higher among women with a child delivered by cesarean section than those of natural delivery [2]. Thus, the types of inspection and treatment provided to elderly pregnant women represent new challenges in obstetrics [3,4]. In this commentary article, we will identify and debate the risks encountered when managing older pregnant women or pregnant women with history of cesarean section or a uterine scar.

Increasing prevalence of infertility

Reproductive age and fertility are negatively correlated as increasing age strongly affects women’s fertility. The quality of woman’s eggs begins to rapidly decline 10 years before menopause as a result of their increasing age and exposure to environmental pollution, electromagnetic radiation, chemicals, and toxins [5]. Infertility at an advanced maternal age (≥35 years) [6] is mainly caused by rapid aging of the eggs, poor oocyte quality, a gradually diminishing ovarian reserve, low implantation rates, abnormal chromosome segregation, and an increased incidence of chromosomal abnormalities [7].

At the same time, elderly women have high rates of abortion. One study reported that 15% of all couples have experienced spontaneous abortion, whereas the spontaneous abortion rate among aged couples is 30%–40% [8]. Couples in which one or both parents had an abnormal chromosome number accounted for 50%–80% of the spontaneous abortions reported among elderly pregnant women. Age-related increases in the number of fatal chromosome abnormalities in couples will certainly lead to increased numbers of spontaneous abortions [9]. Early abortion is caused by an abnormal chromosome number, such as triploid or tetraploid. The second type of abnormal chromosome number is X monosomy (45, XO) or mosaicism (45, XO/46, XX, etc.). While some of these babies can be born, most are lost to abortion. For example, women with the monomer 21 chromosomal defect will find difficulty in giving birth. The third type of abnormal chromosome number is trisomy 18. While most trisomy 16 fetuses are lost to abortion, a few trisomy 21 or 18 fetuses have been born live as an irregular occurrence [10]. Other causes of spontaneous abortion include polysomy, serious abnormal chromosome structures, severe chromosome microdeletion or microrepetition, and other chromosome abnormalities [11].

Increased rate of birth defects

While a fetus with a chromosome aberration is usually lost to spontaneous abortion, a few of them are born alive with birth defects. Recent epidemiological data show that the incidence rate of neonatal congenital heart disease in the cities of Shenzhen and Xi’an has increased significantly in recent years and is likely to occur in the fetuses of mothers aged>35 years [12,13]. Statistics show that the rate of birth defects in Shenzhen reached 13.43% during the period between 2003 and 2009 [14] and reached 12.62% in a district of Beijing between 2006 and 2012 [15]. After implementation of the two-child policy, the mean age of pregnant women became significantly higher than before the policy. Literature reports have indicated that pregnant women aged>34 years have an 8%–15% probability of carrying a malformed fetus [16]. Women aged 35 years usually show degraded ovarian function, impaired split function, and are at an increased risk for gene and chromosome mutations. Men beyond the age of 40 years display reduced sperm replication ability, resulting in an increased probability of gene mutations and faulty hereditary information being transferred to the offspring [17].

As woman’s eggs age, they increasingly suffer the effects of harmful substances and are prone to have a chromosome mutation that can lead to chromosomal dysfunction during cell division. Disorders linked to genetic or chromosomal defects include trisomy 21 syndrome, trisomy 18 syndrome, trisomy 13 syndrome, Turner syndrome, Klinefelter syndrome, 5p syndrome, pathogenic chromosomal microdeletions or mirror repeats, and other congenital malformations found in children [18].

In conclusion, as the age of both parents increases, the child of the parents is likely to be affected by gene mutation, autoimmune disorder, viral infection, or perinatal complication.

Pregnancy complications

Elder maternal age has been considered an independent risk factor for pregnancy complications, and elder multiparous women are more likely to develop gestational diabetes and gestational hypertension disease than other women of childbearing age [19].

Gestational diabetes mellitus

Currently, the overall global incidence rate of gestational diabetes is increasing and is also increasing among elder pregnant women. Survey data gathered in China showed that the mean incidence rate of gestational diabetes is 6.6% and is 7.2% in southern China and 5.1% in northern China.

An elder maternal age has been conclusively identified as a risk factor for gestational diabetes mellitus and impaired glucose tolerance [20]. Furthermore, elderly age has been linked to obesity, which may cause diabetes [21]. Diabetes has a significant effect on the fetus because it is associated with increased rates of preterm birth, macrosomia, dystocia and cesarean section, and intrauterine fetal death. The main reason for the adverse effects of diabetes is that it reduces fetal oxygen supply from the placenta while maintaining persistent high blood sugar levels. This effect can result in severe fetal hypoxia, intrauterine fetal death [4], an increased likelihood of fetal malformation [5] and neonatal death [6], neonatal respiratory distress syndrome, and neonatal hypoglycemia [4].

Gestational diabetes mellitus is an even more dangerous disease than diabetes mellitus, causing both mental and physical issues among pregnant women. To avoid the misdiagnosis and mistreatment of adverse conditions affecting patients with gestational diabetes, those patients must choose a regular hospital for treatment. The principles when treating women with gestational diabetes mellitus are as follows: (1) diet control: only consuming carbohydrates with a low glycemic index and eating frequent small meals; (2) providing insulin therapy if the diabetes cannot be controlled via a strict diet and exercise; (3) providing intensive monitoring before delivery; (4) closely monitoring fetal development and maturity; (5) awareness of indications for a cesarean section; (6) be prepared to treat premature neonates by keeping them warm and providing oxygen; and (7) be prepared to provide early feeding with sugar water and milk, monitoring the infant’s blood glucose level and checking for any newborn malformation.

Hypertensive disorders that complicate pregnancy

Literature reports have stated that the incidence rate of pregnancy-induced hypertension in countries other than China is 7%–12%, whereas the incidence rate of pregnancy-induced hypertension in China ranges from 9.4% to 10.4%. Statistical research reports have shown that elder multiparous women are more likely to develop a hypertensive disorder that complicates their pregnancy than young pregnant women [22]. A possible reason for this difference is that pregnancy causes pressure from family and society. This factor enables these patients to become easily nervous, especially if they have a history of an adverse birth and pregnancy complications. Many older pregnant women develop medical complications, such as hypertension and metabolic diseases, during pregnancy because of their advanced age. Pregnant women over the age of 35 years are prone to develop pregnancy-induced hypertension and even severe preeclampsia [23]. Research data indicate that the risk for preeclampsia increases with the age of the pregnant woman and is 1.5-fold higher among women>40 years of age than in women<35 years of age [24].

Additionally, an older maternal age is associated with underlying disorders, such as high blood glucose levels, high blood lipid levels, and hypertension, which can affect intrauterine fetal growth. Older maternal age is also associated with fetal development problems, fetal distress, an abnormal birth weight, and an increased chance for a premature birth [25]. One study showed that the prevalence rate of neonates with congenital heart disease born to women with maternal diabetes is ~5-fold higher than the prevalence rate of such neonates born to women with other types of illnesses [26]. In addition to the pregnancy-related diseases mentioned above (i.e., pregnancy-induced hypertension, pregnancy-related toxemia, preeclampsia, and gestational diabetes), elder pregnant women are prone to develop chronic diseases, such as hyperthyroidism, kidney diseases, and cardiovascular diseases, all of which increase the incidence of maternal and fetal complications.

Pregnant women with hypertensive disorders require special care. As a result, antenatal care and antihypertensive therapies must be available to actively treat a variety of diseases caused by maternal hypertension. The basic components of such treatment include sedative, antispasmodic, antihypertensive, and diuretic therapies and timely pregnancy termination.

Increased rates of cesarean delivery

The latest clinical research shows that the rate of cesarean section in China (>50% of deliveries) is the highest in the world [27,28]. This high cesarean section rate may be partially attributed to the high percentage of multiparous women with uterine scars [29]. According to the official Chinese data reported in the first quarter of 2014, 45.18% of multiparous women in China had a uterine scar. This percentage increased to 48.85% in the first quarter of 2015. However, this increase was not statistically significant. Given that the policy of allowing two children if one parent is an only child was sanctioned in 2014, studies showed that the choice of delivery method among repregnant women who had previously given birth by cesarean section remained almost constant. Only 16.36% of women who had given a vaginal birth prior to 2014 chose to have cesarean delivery for their second pregnancy. This ratio was 12.83% during the same period in 2015. However, the percentage of women who became pregnant after a previous vaginal delivery (0.97%) was less than the percentage of women who became pregnant after a previous cesarean delivery (1.17%). The percent of second pregnancies delivered by cesarean section increased because labor was less often selected as a delivery modality for a secondary pregnancy among women with a cicatricial uterus and due to the increased percentage of multiparous women with uterine scars. Therefore, we may conclude that the two-child policy may not have reduced the rate of cesarean sections but rather increased that rate.

Repeated cesarean sections may lead to poor wound healing, intestinal adhesions, endometriosis, and an increased incidence of other postpartum complications [30,31]. Therefore, to comprehensively evaluate the first delivery mode, its quality, and the maternal and perinatal situation of the first pregnancy to reduce the risks associated with the delivery of a second child is important [32].

Severe perinatal complications

According to the official Chinese data, the rate of cesarean sections in China reached 54% and even 72% in certain areas of the country in 2014. As a result, most repregnant women will have uterine scars that can significantly increase their probability of having an adherent placenta, placenta accrete, or placenta previa [33]. Moreover, having a vaginal delivery after a cesarean section increases the probability of a spontaneous rupture of the incision made on the lower uterine segment. Therefore, many pregnant women with a history of cesarean section have selected the cesarean delivery mode for their second child [9]. The most common and serious perinatal complications of cesarean section are placenta previa and postpartum hemorrhage [34].

Pernicious placenta previa

The rising rates of cesarean section, older maternal age, artificial abortion operations, and other related factors have caused a yearly increase in the number of women with pernicious placenta previa. This disorder is very prone to cause massive hemorrhage during an operation and provides difficulty in achieving hemostasis. When hemorrhage occurs, maternal shock due to bleeding can develop very rapidly. This phenomenon significantly increases the need for uterus resection as well as the possibility of maternal death [35,36]. Statistical research has shown that the proportion of hysterectomies caused by placenta previa in all peripartum hysterectomy patients has increased to 40%–60% [37]. A study by Clark and Silver [38] showed that the prevalence of placenta accreta and incidence of cesarean sections are positively correlated. Those investigators found that 0.24% of pregnant women with placenta accreta showed no history of cesarean section. However, that percentage was significantly high among such pregnant women with a history of three, four, or five cesarean sections (0.57%, 2.13%, and 2.33%, respectively).

To date, no unified guide is available for the clinical treatment for placenta previa. Moreover, individualized therapy is administered to patients diagnosed as pernicious placenta previa. Conservative surgical treatment of pernicious placenta previa usually produces complications of severe bleeding, infection, and disseminated intravascular coagulation, which may require treatment with laparotomy or uterus resection. In recent years, Chinese physicians have used several methods to avoid hysterectomy. These methods include a transverse “U” suture at the lower uterine segment, local wound suture, local uterine wall resection, embolization of the bilateral uterine artery, and the insertion of a uterine packing gauze or a water sac [39‒41]. If the implanted area of the placenta exceeds 33%, the implanted material covers the uterine muscular layer or the bleeding volume exceeds 2500 mL. A variety of measures may fail to stop bleeding, and the uterus may have to be removed. Balloon occlusion is an important method for temporarily blocking blood supply and has attracted considerable attention. The present technology accurately delivers and positions an intravascular balloon under the surveillance of digital subtraction angiography equipment. The use of this method can reduce intraoperative bleeding and improve the safety of surgery [42]. Since 2015, our group has obtained good results when inserting a bilateral iliac balloon prior to a cesarean section operation (data not published), which is consistent with the results reported in the literature [43].

Postpartum hemorrhage

Postpartum hemorrhage is a complication that can endanger the life of the mother during child birth. Numerous studies have shown the prevalence of postpartum hemorrhage to be ~4.26%. The probability ratio of postpartum hemorrhage caused by cesarean section is 1.67-fold greater than that caused by vaginal birth. Thus, postpartum hemorrhage represents a serious threat to the health of a pregnant women and the fetus. The main causes of postpartum hemorrhage include uterine inertia, placental problems, soft birth canal laceration, coagulopathy, and uterus inversion [44]. Additionally, postpartum hemorrhage can be induced by abortion, delivery, psychological factors, and various pregnancy-related complications [45].

Based on its pathogeny, the methods used to treat postpartum hemorrhage include rapid hemostasis, blood supplementation, correction of patient shock, infection prevention and control, and uterine arterial embolization occlusion by intervention method. In some cases, hysterectomy may be required to save the patient’s life [46].

Increased incidence of postpartum depression

Women pregnant with their second child are often in a career advancement or stable portion of their life. Thus, they may have some of the following concerns related to their pregnancy: the loss of some occupation-promotion opportunities, worries about the risk of health problems during pregnancy and the neonatal period, the pressure of social and economic factors, and depression and other negative emotions [47]. Postpartum depression can be caused by dysfunction of the advanced maternal neurohumoral system [48]. Additionally, the combined effects of gestational diabetes mellitus and socioeconomic factors can promote postpartum depression among elderly mother with a twin pregnancy [49]. A large multicenter clinical study showed that having several children in a family [50] and a high cesarean section rate [51] will increase the incidence of postpartum depression.

Conclusions

The total number of deliveries in hospitals increased significantly after implementation of the two-child policy. At the same time, the numbers of elderly multipara, poorly educated multipara, and repeated abortion parous women who delivered babies also increased. As a result, the numbers of pregnancies complicated by severe gestational hypertension and (or) postpartum hemorrhage increased, emphasizing the need for comprehensive pregnancy and childbirth management policies [52].

Furthermore, more parous women with an extensively scarred uterus will need to deal with pregnancy and childbirth. Thus, to reduce the rate of cesarean sections in primipara, carefully checking for indications of surgery, renewing a pregnancy idea, improving skills, and encouraging vaginal delivery for women with a scarred uterus will be necessary. Various measures must be taken to reduce the complication rate and improve maternal and fetal outcomes.

References

[1] Padmadas SS. Two-child policy in China: rhetoric versus reality. Ann Hum Biol 2017; 44(2): 97–98

[2] Koo YJ, Ryu HM, Yang JH, Lim JH, Lee JE, Kim MY, Chung JH. Pregnancy outcomes according to increasing maternal age. Taiwan J Obstet Gynecol 2012; 51(1): 60–65

[3] Gong W, Xu DR, Caine ED. Challenges arising from China’s two-child policy. Lancet 2016; 387(10025): 1274

[4] Liu X, Zhang W. Effect of maternal age on pregnancy: a retrospective cohort study. Chin Med J (Engl) 2014; 127(12): 2241–2246

[5] Zheng T, Sun A, Lang J, Deng Y, Chen R, Tian Q, Deng S. Change tendency during 30 years of infertility and endometriosis in Peking Union Medical College Hospital. Chin J Obstet Gynecol (Zhonghua Fu Chan Ke Za Zhi) 2015; 50(8): 591–595 (in Chinese)

[6] Hu H, Yang H, Yin Z, Zhao L. Chromosome examination of missed abortion patients. Chin Med J (Zhonghua Yi Xue Za Zhi) 2015; 95(35): 2837–2840 (in Chinese)

[7] Usmani A, Rehman R, Qamar A. Effect of age on uterine and ovarian morphology with polycystic ovaries. J Pak Med Assoc 2014; 64(10): 1119–1122

[8] Agenor A, Bhattacharya S. Infertility and miscarriage: common pathways in manifestation and management. Womens Health (Lond) 2015; 11(4): 527–541

[9] Li Y, Gong Y, Liu H, Song Y, He W, Wei J, Sun X, Chen X. Detection for chromosomal aberrations in 43 fetuses with spontaneous abortion and stillbirth by array-based comparative genomic hybridization. Chin J Med Genet (Zhonghua Yi Xue Yi Chuan Xue Za Zhi)  2015; 32(3): 348–352 (in Chinese)

[10] Neusser M, Rogenhofer N, Durl S, Ochsenkuhn R, Trottmann M, Jurinovic V, Steinlein O, von Schonfeldt V, Muller S, Thaler CJ. Increased chromosome 16 disomy rates in human spermatozoa and recurrent spontaneous abortions. Fertil Steril 2015; 104(5): 1130–1137. e1–e10

[11] Rabiega-Gmyrek D, Olejniczak T, Niepsuj-Biniaś J, Guglas-Bochyńska B, Jachowski P, Latos-Bieleńska A, Opala T. Chromosomal aberrations—the cause of spontaneous abortions. Ginekol Pol 2015; 86(5): 357–361 (in Polish) 

[12] Yu M, Ping Z, Zhang S, He Y, Dong R, Guo X. The survey of birth defects rate based on birth registration system. Chin Med J (Engl) 2016; 129(17): 2140 

[13] Luo YL, Cheng YL, Gao XH, Tan SQ, Li JM, Wang W, Chen Q. Maternal age, parity and isolated birth defects: a population-based case-control study in Shenzhen, China. PLoS One 2013; 8(11): e81369

[14] Yang M, Zhang S, Du Y. Epidemiology characteristics of birth defects in Shenzhen city during 2003 to 2009, China. J Matern Fetal Neonatal Med 2015; 28(7): 799–803

[15] Yu JR, Jin L, Xiao LH, Jin L. Prevalence of birth defects in the Tongzhou District of Beijing between 2006 and 2012. Chin J Contemp Pediatr (Zhongguo Dang Dai Er Ke Za Zhi) 2014; 16(11): 1133–1137 (in Chinese) 

[16] Han XY, Jin L, Fan GS, Xiang Y, Liu XY, Hao N, Cui QC. Fetal anomalies in second trimester in recent ten years: clinical analysis of 116 cases. Chin Med J (Zhonghua Yi Xue Za Zhi) 2009; 89(15): 1053–1056 (in Chinese)

[17] Elhanbly S, El-Saied MA, Fawzy M, El-Refaeey A, Mostafa T. Relationship of paternal age with outcome of percutaneous epididymal sperm aspiration-intracytoplasmic sperm injection, in cases of congenital bilateral absence of the vas deferens. Fertil Steril 2015; 104(3): 602–606

[18] Zigman WB. Atypical aging in Down syndrome. Dev Disabil Res Rev 2013; 18(1): 51–67

[19] Alsammani MA, Ahmed SR. Grand multiparity: risk factors and outcome in a tertiary hospital: a comparative study. Mater Sociomed 2015; 27(4): 244–247

[20] Helseth R, Salvesen O, Stafne SN, Mørkved S, Salvesen KA, Carlsen SM. Gestational diabetes mellitus among Nordic Caucasian women: prevalence and risk factors according to WHO and simplified IADPSG criteria. Scand J Clin Lab Invest 2014; 74(7): 620–628

[21] Bogaerts AF, Devlieger R, Nuyts E, Witters I, Gyselaers W, Van den Bergh BR. Effects of lifestyle intervention in obese pregnant women on gestational weight gain and mental health: a randomized controlled trial. Int J Obes 2013; 37(6): 814–821

[22] Berhan Y, Endeshaw G. Maternal mortality predictors in women with hypertensive disorders of pregnancy: a retrospective cohort study. Ethiop J Health Sci 2015; 25(1): 89–98

[23] Li X, Tan H, Huang X, Zhou S, Hu S, Wang X, Xu X, Liu Q, Wen SW. Similarities and differences between the risk factors for gestational hypertension and preeclampsia: a population based cohort study in south China. Pregnancy Hypertens 2016; 6(1): 66–71

[24] Wielgos A, Szymusik I, Bartnik P, Kacperczyk J, Kosinska-Kaczynska K, Pietrzak B. Pregnancy beyond the age of 40— the influence of parity on perinatal outcome. Neuro Endocrinol Lett 2015; 36(4): 387–393

[25] Jiang HQ, Chen H, Yang J. Characteristics of blood lipids levels and relevant factor analysis during pregnancy. Chin Med J (Zhonghua Yi Xue Za Zhi) 2016; 96(9): 724–726 (in Chinese)

[26] Mahaba HM, Ismail NA, El Damaty SI, Kamel HA. Pre-eclampsia: epidemiology and outcome of 995 cases. J Egypt Public Health Assoc 2001; 76(5-6): 357–368

[27] Barros FC, Matijasevich A, Maranhão AG, Escalante JJ, Rabello Neto DL, Fernandes RM, Vilella ME, Matos AC, Albuquerque C, Léon RG, Victora CG. Cesarean sections in Brazil: will they ever stop increasing? Rev Panam Salud Publica 2015; 38(3): 217–225

[28] Hu LQ, Flood P, Li Y, Tao W, Zhao P, Xia Y, Pian-Smith MC, Stellaccio FS, Ouanes JP, Hu F, Wong CA. No pain labor & delivery: a global health initiative’s impact on clinical outcomes in China. Anesth Analg 2016; 122(6): 1931–1938

[29] Mehta S, Tran K, Stewart L, Soutter E, Nauta M, Yoong W. Pregnancy outcomes in women greater than 45 years: a cohort control study in a multi-ethnic inner city population. Arch Gynecol Obstet 2014; 289(5): 1125–1128

[30] Gao L, Huang Z, Zhang X, Zhou N, Huang X, Wang X. Reproductive outcomes following cesarean scar pregnancy — a case series and review of the literature. Eur J Obstet Gynecol Reprod Biol 2016; 200: 102–107

[31] Özcan S, Karayalçın R, Kanat Pektas M, Artar I, Sucak A, Çelen S, Danisman N. Multiple repeat cesarean delivery is associated with increased maternal morbidity irrespective of placenta accreata. Eur Rev Med Pharmacol Sci 2015; 19(11): 1959–1963

[32] Richards MK, Flanagan MR, Littman AJ, Burke AK, Callegari LS. Primary cesarean section and adverse delivery outcomes among women of very advanced maternal age. J Perinatol 2016; 36(4): 272–277

[33] Yu L, Hu KJ, Yang HX. A retrospective analysis on the pernicious placenta previa from 2008 to 2014. Chin J Obstet Gynecol (Zhonghua Fu Chan Ke Za Zhi) 2016; 51(3): 169–173 (in Chinese)

[34] Palova E, Redecha M, Malova A, Hammerova L, Kosibova Z. Placenta accreta as a cause of peripartum hysterectomy. Bratisl Lek Listy 2016; 117(4): 212–216

[35] Zhu CK, Wang F, Zhou YM, Ying J, Chen DQ. Maternal outcomes in pregnant women with pernicious placenta previa. J Zhejiang Univ (Med Sci) (Zhejiang Da Xue Xue Bao Yi Xue Ban) 2015; 44(3): 253–257 (in Chinese)

[36] Chen J, Cui H, Na Q, Li Q, Liu C. Analysis of emergency obstetric hysterectomy: the change of indications and the application of intraoperative interventions. Chin J Obstet Gynecol (Zhonghua Fu Chan Ke Za Zhi) 2015; 50(3): 177–182 (in Chinese)

[37] Gurol-Urganci I, Cromwell DA, Edozien LC, Smith GC, Onwere C, Mahmood TA, Templeton A, van der Meulen JH. Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis. BMC Pregnancy Childbirth 2011; 11(1): 95

[38] Clark EA, Silver RM. Long-term maternal morbidity associated with repeat cesarean delivery. Am J Obstet Gynecol 2011; 205(6 Suppl): S2–S10

[39] Yan J, Shi CY, Yu L, Yang HX. Folding sutures following tourniquet binding as a conservative surgical approach for placenta previa combined with morbidly adherent placenta. Chin Med J (Engl) 2015; 128(20): 2818–2820

[40] Li GT, Li GR, Li XF, Wu BP. Funnel compression suture: a conservative procedure to control postpartum bleeding from the lower uterine segment. BJOG 2016; 123(8): 1380–1385

[41] Du X, Xie X, Wang Y. Uterine artery suture: a preventive approach for pernicious placenta previa. Cell Biochem Biophys 2014; 68(2): 407–410

[42] Zeng H, Wang Y, Wang Y, Guo XY. Perioperative management of abdominal aortic balloon occlusion in patients complicated with placenta percteta: a case report. J Peking Univ (Health Sci) (Beijing Da Xue Xue Bao Yi Xue Ban) 2015; 47(6): 1031–1033 (in Chinese)

[43] Xu JQ. Effectiveness of embolization of the internal iliac or uterine arteries in the treatment of massive obstetrical and gynecological hemorrhages. Eur Rev Med Pharmacol Sci 2015; 19(3): 372–374

[44] Cavazos-Rehg PA, Krauss MJ, Spitznagel EL, Bommarito K, Madden T, Olsen MA, Subramaniam H, Peipert JF, Bierut LJ. Maternal age and risk of labor and delivery complications. Matern Child Health J 2015; 19(6): 1202–1211

[45] Chi Z, Zhang S, Wang Y, Yang L, Yang Y, Li X. Research of the assessable method of postpartum hemorrhage. Technol Health Care 2016; 24(Suppl 2): S465–S469

[46] Tang PP, Hu HY, Gao JS, Hu J, Zhong YF, Wang T, Song YN, Zhou XY, Yang JQ, Liu JT, Pan J, Shi HF. Evaluation of efficacy and safety of pelvic arterial embolization in women with primary postpartum hemorrhage. Chin J Obstet Gynecol (Zhonghua Fu Chan Ke Za Zhi) 2016; 51(2): 81–86 (in Chinese)

[47] Xie YC, Yuan HW, Zhuang RJ, Han CH, Liu SH, Chen SF, Fu ZW, Wang ZM, Qiao SZ, Guo L, Zhang HY. Study on the status and related socio-psychological factors of maternal depression among high-risk pregnancy women in Harbin city. Chin J Prev Med (Zhonghua Yu Fang Yi Xue Za Zhi) 2012; 46(6): 543–546 (in Chinese)

[48] Sockol LE, Battle CL. Maternal attitudes, depression, and anxiety in pregnant and postpartum multiparous women. Arch Women Ment Health 2015; 18(4): 585–593

[49] Walmer R, Huynh J, Wenger J, Ankers E, Mantha AB, Ecker J, Thadhani R, Park E, Bentley-Lewis R. Mental health disorders subsequent to gestational diabetes mellitus differ by race/ethnicity. Depress Anxiety 2015; 32(10): 774–782

[50] Yang F, Gardner CO Jr, Bigdeli T, Gao J, Zhang Z, Tao M, Liu Y, Li Y, Wang G, Shi J, Gao C, Zhang K, Li K, Wang X, Liu L, Sun J, Du B, Shi S, Zhang J, Wu W, Wang X, Shen J, Liu T, Gu D, Liang W, Deng H, Pan J, Yang L, Jian H, Jiang G, Meng H, Miao G, Li Y, Hu C, Huang G, Zhang Y, Chen Y, Ha B, Gao S, Fang X, Mei Q, Hong X, Yang D, Liu T, Fengyu Y, Zhong H, Sang H, Chen G, Cai M, Song Y, Dong J, Shen Z, Zhang W, Wang X, Pan R, Liu X, Li Y, Liu Z, Zhang Q, Li G, Flint J, Kendler KS. Clinical features of and risk factors for major depression with history of postpartum episodes in Han Chinese women: a retrospective study. J Affect Disord 2015; 183: 339–346

[51] Xie RH, Lei J, Wang S, Xie H, Walker M, Wen SW. Cesarean section and postpartum depression in a cohort of Chinese women with a high cesarean delivery rate. J Womens Health (Larchmt) 2011; 20(12): 1881–1886

[52] Jnifen A, Fadhlaoui A, Chaker A, Zhioua F. Particularities of pregnancy and labor in 40-year-old women. Report of 300 cases. Tunis Med 2010; 88(11): 829–833 (in French)

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag GmbH Germany