Journal of the American College of Nutrition
ISSN: 0731-5724 (Print) 1541-1087 (Online) Journal homepage: http://www.tandfonline.com/loi/uacn20
What is so bad about a prolonged pregnancy? L Jovanovic-Peterson To cite this article: L Jovanovic-Peterson (1991) What is so bad about a prolonged pregnancy?, Journal of the American College of Nutrition, 10:1, 1-2, DOI: 10.1080/07315724.1991.10718118 To link to this article: http://dx.doi.org/10.1080/07315724.1991.10718118
Published online: 02 Sep 2013.
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Date: 20 December 2015, At: 10:42
Downloaded by [University of California, San Diego] at 10:43 20 December 2015
Guest Editorial: What Is So Bad About a Prolonged Pregnancy?
It is a kneejerk response in the United States for clinicians to prescribe prenatal vitamins to a pregnant woman [1]. In fact, if a woman has a preexisting medical problem, the tendency is to prescribe the vitamins upon her first booking. The Diabetes and Early Pregnancy Study, an NICHD-funded five-university center col laborative trial in which diabetic and nondiabetic women were followed preconceptionally until delivery, noted that a majority of the diabetic women were taking prena tal vitamins by the 12th week of gestation, whereas only a small minority of the control women were taking prenatal vitamins in the first trimester. By the second half of the pregnancy, 100% of both groups reported taking the vitamins [2]. Currently, prenatal vitamins prescribed in the United States contain 40-65 mg of iron per tablet. The daily iron requirement has been estimated to be 30 mg/day. The paper in this issue entitled "A Randomized Com parison of Routine Versus Selective Iron Supplementa tion During Pregnancy" by Drs. Hemminki and Rimpelä [3] presents data which suggest that routine iron sup plementation in pregnancy may produce more harm than benefit. Not only did more women in the routinely sup plemented group have subjective adverse effects, the data suggest a trend toward prolonging the pregnancy when iron is given prophylactically. Although prematurity is a major cause of neonatal morbidity and mortality [4], prolonged pregnancy or "postdatism" produces its own set of problems. Postdatism is defined as a pregnancy which goes beyond 42 completed weeks (normal term pregnancy averages 40 weeks). The incidence of postdatism has been reported in from 3.5 to 14% of all pregnancies [5]. Of these, 40% of the babies manifest "post maturity syndrome" (Table 1). The incidence of prolonged preg nancy is increased following threatened abortion, with the first pregnancy, in the very young and older gravida, of low socioeconomic status, and, as per these new data [3], with use of routine iron supplementation. The recur rence risk following one prolonged pregnancy is 50% [6]. Prolonged pregnancy is associated with increased in cidence of placental lesions, fetal hypoxia and asphyxia, intrauterine growth retardation, macrosomia, meconium staining and aspiration, and prenatal death [7]. Mean
gestational duration for fetuses presenting with unex pected intrapartum asphyxia has been observed to be 289 days, and for those who died or had neurologic symptoms following unexpected intrapartum asphyxia, 291 days [8]. Prolonged pregnancy is a common cause of intrapartum asphyxia, and one-third are complicated by fetal distress [9]. Incidence of caesarean section for failed progression of labor, macrosomia, and fetal dis tress is increased [10]. The incidence of congenital anomalies is increased in prolonged pregnancies to 2.5% as compared with 1.8% in term infants [9]. Of all anomalies, the greatest is ob served in central nervous system malformations [11]. Given the same severe congenital anomaly, the post-term infant is more likely to die than the term infant [11]. Fetal and neonatal death rates and mortality for the first 2 years of life in the post-term infant are double those for the term infant. The neonatal death rate is increased for extrinsic perinatal hypoxia, congenital anomalies, birth injury, and pulmonary disorders, with no single group of causes being responsible for the overall increase in neonatal mortality [9-11]. Neonatal morbidity and ill ness for the first 3 years of life are also increased [11]. In general, the longer the pregnancy extends post-term, the greater the likelihood for the development of placental insufficiency, fetal growth retardation, and hypoxia [9]. Comparing infants of prolonged pregnancy with in fants who developed postmaturity syndrome, infants of the prolonged pregnancies experienced more perinatal complications, including increased incidence of late decelerations in labor, increased incidence of caesarean section for failed progress, decreased 5-min Apgar scores, and increased perinatal mortality [9]. Postma turity syndrome is associated with a sevenfold increase in the incidence of neonatal death [11]. These infants also have lower developmental scores at birth and at 4 months of age, and, although their motor scores are equivalent to term infants at 8 months, they exhibit in creased incidence of illness and feeding and sleep distur bances [12]. Placental lesions associated with prolonged pregnan cies are increased infarctions, increased fibrin deposi tion, increased calcification, decreased villous capil laries, and reduced intervillous space. These changes may represent decreased placental reserve [13].
Journal of the American College of Nutrition, Vol. 10, No. 1, 1-2 (1991) © 1991 John Wiley & Sons, Inc.
CCC 0731-5724/91/010001-02$04.00
Editorial
Downloaded by [University of California, San Diego] at 10:43 20 December 2015
Table 1. Characteristics of Infants with Postmaturity Syndrome Failure of intrauterine growth Dehydration Development of dry, cracked, wrinkled, parchmentlike skin Reduced subcutaneous fat deposits Long thin arms and legs Advanced hardness of the skull Absence of vernix caseosa and lanugo hair Skin maceration Brownish-green or yellowish discoloration of skin, umbilical cord, and membranes Alert, "little-old-man-like" appearance
It is clear that we must identify women at risk for postdatism and institute measures to prevent infant mor bidity and mortality. If iron does prolong pregnancy mediated by iron inhibition of intestinal absorption of zinc [14], which is implicated as necessary to initiate labor [15], then we should not routinely prescribe iron supplementation to all pregnant women. Instead, we should monitor the woman's hemoglobin concentration and only prescribe iron when true anemia occurs.
REFERENCES 1. Johnson TRB, Walker MA, Niebyl JR: In Gabbe SG, Niebyl JR, Simpson JL (eds): "Prenatal Care in Obstetrics." New York: Churchill Livingston, p 173,1986. 2. Mills JL, Knopp RL, Simpson JL, et al: Lack of relation between malformation rates in infants of diabetic mothers to glycémie control during organogeneses. New Engl J Med 318:671-676, 1988. 3. Hemminki E, Rimpelä U: A randomized comparison of routine versus selective iron supplementation during preg nancy. J Am Coll Nutr 10:3-10,1991. 4. Stevenson DK, Petersen KR, Yates BL, Benitz WE, Gale R: Outcome of neonates with birth weights of less than 801 grams. J Perinatol 8:82-87, 1988. 5. Beischer NA, Evans JH, Townsend L: Studies in prolonged pregnancy. I. The incidence of prolonged preg nancy. Am J Obstet Gynecol 103:476, 1979. 6. Vorherr H: Placental insufficiency in relation to postterm pregnancy and fetal postmaturity. Evaluation of placental function; the management of the postterm gravida. Am J
2
Obstet Gynecol 123:67, 1975. 7. Grausz JP, Heimler R: Asphyxia and gestational age. Obstet Gynecol 62:175, 1983. 8. Rayburn WF, Motley ME, Stemple LE, et al: Antepartum prediction of the postmature infant. Obstet Gynecol 60:148, 1982. 9. Zweidling MA: Factors pertaining to prolonged pregnancy and its outcome. Pediatrics 40:202, 1967. 10. Homburg R, Ludomirski A, Insler V: Detection of fetal risk in postmaturity. Br J Obstet Gynaecol 86:759, 1979. 11. Yeh SY, Read JA: Management of postterm pregnancy in a large obstetrical population. Obstet Gynecol 60:282, 1982. 12. Field TM, Dabiri C, Hailock M, et al: Developmental ef fects of prolonged pregnancy and the postmaturity syndrome. J Pediatr 90:836, 1977. 13. Callenbach JC, Hall RT: Morbidity and mortality of ad vanced gestational age: postterm or postmature. Obstet Gynecol 53:721, 1979. 14. Hambidge KM, Krebs NF, Favier A, Guyette L, Ikle DN: Zinc nutritional status during pregnancy: a longitudinal study. Am J Clin Nutr 37:429-442,1983. 15. Kynast G, Saling E: The relevance of zinc in pregnancy. J Perinat Med 8:171-182,1980. Lois Jovanovic-Peterson, MD Sansum Medical Research Foundation 2219 Bath Street Santa Barbara, CA 93105
Received September 1990.
VOL. 10, NO. 1
ISSN: 0731-5724 (Print) 1541-1087 (Online) Journal homepage: http://www.tandfonline.com/loi/uacn20
What is so bad about a prolonged pregnancy? L Jovanovic-Peterson To cite this article: L Jovanovic-Peterson (1991) What is so bad about a prolonged pregnancy?, Journal of the American College of Nutrition, 10:1, 1-2, DOI: 10.1080/07315724.1991.10718118 To link to this article: http://dx.doi.org/10.1080/07315724.1991.10718118
Published online: 02 Sep 2013.
Submit your article to this journal
View related articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=uacn20 Download by: [University of California, San Diego]
Date: 20 December 2015, At: 10:42
Downloaded by [University of California, San Diego] at 10:43 20 December 2015
Guest Editorial: What Is So Bad About a Prolonged Pregnancy?
It is a kneejerk response in the United States for clinicians to prescribe prenatal vitamins to a pregnant woman [1]. In fact, if a woman has a preexisting medical problem, the tendency is to prescribe the vitamins upon her first booking. The Diabetes and Early Pregnancy Study, an NICHD-funded five-university center col laborative trial in which diabetic and nondiabetic women were followed preconceptionally until delivery, noted that a majority of the diabetic women were taking prena tal vitamins by the 12th week of gestation, whereas only a small minority of the control women were taking prenatal vitamins in the first trimester. By the second half of the pregnancy, 100% of both groups reported taking the vitamins [2]. Currently, prenatal vitamins prescribed in the United States contain 40-65 mg of iron per tablet. The daily iron requirement has been estimated to be 30 mg/day. The paper in this issue entitled "A Randomized Com parison of Routine Versus Selective Iron Supplementa tion During Pregnancy" by Drs. Hemminki and Rimpelä [3] presents data which suggest that routine iron sup plementation in pregnancy may produce more harm than benefit. Not only did more women in the routinely sup plemented group have subjective adverse effects, the data suggest a trend toward prolonging the pregnancy when iron is given prophylactically. Although prematurity is a major cause of neonatal morbidity and mortality [4], prolonged pregnancy or "postdatism" produces its own set of problems. Postdatism is defined as a pregnancy which goes beyond 42 completed weeks (normal term pregnancy averages 40 weeks). The incidence of postdatism has been reported in from 3.5 to 14% of all pregnancies [5]. Of these, 40% of the babies manifest "post maturity syndrome" (Table 1). The incidence of prolonged preg nancy is increased following threatened abortion, with the first pregnancy, in the very young and older gravida, of low socioeconomic status, and, as per these new data [3], with use of routine iron supplementation. The recur rence risk following one prolonged pregnancy is 50% [6]. Prolonged pregnancy is associated with increased in cidence of placental lesions, fetal hypoxia and asphyxia, intrauterine growth retardation, macrosomia, meconium staining and aspiration, and prenatal death [7]. Mean
gestational duration for fetuses presenting with unex pected intrapartum asphyxia has been observed to be 289 days, and for those who died or had neurologic symptoms following unexpected intrapartum asphyxia, 291 days [8]. Prolonged pregnancy is a common cause of intrapartum asphyxia, and one-third are complicated by fetal distress [9]. Incidence of caesarean section for failed progression of labor, macrosomia, and fetal dis tress is increased [10]. The incidence of congenital anomalies is increased in prolonged pregnancies to 2.5% as compared with 1.8% in term infants [9]. Of all anomalies, the greatest is ob served in central nervous system malformations [11]. Given the same severe congenital anomaly, the post-term infant is more likely to die than the term infant [11]. Fetal and neonatal death rates and mortality for the first 2 years of life in the post-term infant are double those for the term infant. The neonatal death rate is increased for extrinsic perinatal hypoxia, congenital anomalies, birth injury, and pulmonary disorders, with no single group of causes being responsible for the overall increase in neonatal mortality [9-11]. Neonatal morbidity and ill ness for the first 3 years of life are also increased [11]. In general, the longer the pregnancy extends post-term, the greater the likelihood for the development of placental insufficiency, fetal growth retardation, and hypoxia [9]. Comparing infants of prolonged pregnancy with in fants who developed postmaturity syndrome, infants of the prolonged pregnancies experienced more perinatal complications, including increased incidence of late decelerations in labor, increased incidence of caesarean section for failed progress, decreased 5-min Apgar scores, and increased perinatal mortality [9]. Postma turity syndrome is associated with a sevenfold increase in the incidence of neonatal death [11]. These infants also have lower developmental scores at birth and at 4 months of age, and, although their motor scores are equivalent to term infants at 8 months, they exhibit in creased incidence of illness and feeding and sleep distur bances [12]. Placental lesions associated with prolonged pregnan cies are increased infarctions, increased fibrin deposi tion, increased calcification, decreased villous capil laries, and reduced intervillous space. These changes may represent decreased placental reserve [13].
Journal of the American College of Nutrition, Vol. 10, No. 1, 1-2 (1991) © 1991 John Wiley & Sons, Inc.
CCC 0731-5724/91/010001-02$04.00
Editorial
Downloaded by [University of California, San Diego] at 10:43 20 December 2015
Table 1. Characteristics of Infants with Postmaturity Syndrome Failure of intrauterine growth Dehydration Development of dry, cracked, wrinkled, parchmentlike skin Reduced subcutaneous fat deposits Long thin arms and legs Advanced hardness of the skull Absence of vernix caseosa and lanugo hair Skin maceration Brownish-green or yellowish discoloration of skin, umbilical cord, and membranes Alert, "little-old-man-like" appearance
It is clear that we must identify women at risk for postdatism and institute measures to prevent infant mor bidity and mortality. If iron does prolong pregnancy mediated by iron inhibition of intestinal absorption of zinc [14], which is implicated as necessary to initiate labor [15], then we should not routinely prescribe iron supplementation to all pregnant women. Instead, we should monitor the woman's hemoglobin concentration and only prescribe iron when true anemia occurs.
REFERENCES 1. Johnson TRB, Walker MA, Niebyl JR: In Gabbe SG, Niebyl JR, Simpson JL (eds): "Prenatal Care in Obstetrics." New York: Churchill Livingston, p 173,1986. 2. Mills JL, Knopp RL, Simpson JL, et al: Lack of relation between malformation rates in infants of diabetic mothers to glycémie control during organogeneses. New Engl J Med 318:671-676, 1988. 3. Hemminki E, Rimpelä U: A randomized comparison of routine versus selective iron supplementation during preg nancy. J Am Coll Nutr 10:3-10,1991. 4. Stevenson DK, Petersen KR, Yates BL, Benitz WE, Gale R: Outcome of neonates with birth weights of less than 801 grams. J Perinatol 8:82-87, 1988. 5. Beischer NA, Evans JH, Townsend L: Studies in prolonged pregnancy. I. The incidence of prolonged preg nancy. Am J Obstet Gynecol 103:476, 1979. 6. Vorherr H: Placental insufficiency in relation to postterm pregnancy and fetal postmaturity. Evaluation of placental function; the management of the postterm gravida. Am J
2
Obstet Gynecol 123:67, 1975. 7. Grausz JP, Heimler R: Asphyxia and gestational age. Obstet Gynecol 62:175, 1983. 8. Rayburn WF, Motley ME, Stemple LE, et al: Antepartum prediction of the postmature infant. Obstet Gynecol 60:148, 1982. 9. Zweidling MA: Factors pertaining to prolonged pregnancy and its outcome. Pediatrics 40:202, 1967. 10. Homburg R, Ludomirski A, Insler V: Detection of fetal risk in postmaturity. Br J Obstet Gynaecol 86:759, 1979. 11. Yeh SY, Read JA: Management of postterm pregnancy in a large obstetrical population. Obstet Gynecol 60:282, 1982. 12. Field TM, Dabiri C, Hailock M, et al: Developmental ef fects of prolonged pregnancy and the postmaturity syndrome. J Pediatr 90:836, 1977. 13. Callenbach JC, Hall RT: Morbidity and mortality of ad vanced gestational age: postterm or postmature. Obstet Gynecol 53:721, 1979. 14. Hambidge KM, Krebs NF, Favier A, Guyette L, Ikle DN: Zinc nutritional status during pregnancy: a longitudinal study. Am J Clin Nutr 37:429-442,1983. 15. Kynast G, Saling E: The relevance of zinc in pregnancy. J Perinat Med 8:171-182,1980. Lois Jovanovic-Peterson, MD Sansum Medical Research Foundation 2219 Bath Street Santa Barbara, CA 93105
Received September 1990.
VOL. 10, NO. 1
