The role of maternal age in fetal development

JOURNAL OF MEDICAL RESEARCH THE ROLE OF MATERNAL AGE IN FETAL DEVELOPMENT Le Thi Anh Dao, Ta Thanh Van Hanoi Medical University Maternal age is an important prognostic factor in the development of a fetus This study aimed to explore the relationship between fetal development and maternal age for women with a history of recurrent miscarriages This cross - sectional study was conducted at the National Hospital of Obstetrics and Gynecology in Vietnam, from 1st January 2012 to 1st July 2014 A total of 301 newly pregnant patients who had experienced two or more consecutive miscarriages participated in the study The average age of participants was 29.08 ± 5.64 Based on our findings, the relationship between maternal age and the possibility of a baby being born alive can be described in the following equation: Possibility of pregnancy = e (3,760017 - 0,912499 x (mother’s age)) Here, e = 2.71; the correlation coefficient R2 = 0.0274 In the case of mothers under 20 years old, the possibility of a baby being born alive was found to be 89 - 87% For mothers age 20 - 29, the percentage was 86 72% For mothers age 36 to 40 years old, it was 57 - 47% and it decreased to 45 - 30% for those aged above 40 years old Thus, higher maternal age was associated with lower likelihood of giving birth to a live child Keywords: Recurrent miscarriages, Maternal age, Fetal development I INTRODUCTION the older a mother is, the more deteriorated Maternal age is a major factor influencing fetal conception and development In a register - based study of 634,272 Danish pregnant women who were hospitalized between 1978 and 1992, miscarriage rates were found to be almost identical among women age 30 - 34 the ovule quality and the more the endometrium changes in ways that are not conducive to conception [4] Therefore, higher maternal age is associated with higher risk of miscarriage and lower rates of normal pregnancies years with recurrent miscarriages and those aged 35 - 39 with recurrent miscarriages (with a rate of 38 - 40%), but increased to 70% in women aged 40 - 44 [1] This would suggest that the impact of age on miscarriage rates among women with recurrent miscarriages is quite modest until age 40, but beyond age 40, age is the strongest prognostic factor of fetal survival This assertion is also consistent with previous findings [2; 3] According to Simpson, Recurrent miscarriage is defined as or more consecutive miscarriages when the fetus is under 22 weeks old, excluding cases of ectopic pregnancy, hydatidiform mole and biochemical pregnancy [5] Finding and treating the causes of recurrent miscarriages remains a major challenge for obstetricians Although there have been many advances in medical testing to study miscarriages, the causes of only about 50% of miscarriages can be determined [6 - 8] Corresponding author: Le Thi Anh Dao, Hanoi Medical University E-mail: leanhdao1610@gmail.com Received: 20 October 2016 Accepted: 10 December 2016 JMR 105 E1 (7) - 2016 In cases where the exact cause of a miscarriage can not be determined by traditional medical testing, doctors have to rely on other factors to predict what might have caused it 103 JOURNAL OF MEDICAL RESEARCH Maternal age is often mentioned in studies minimum sample size of n = 254 participants looking at causes of miscarriages in other was determined using the following equation: parts of the globe, but the relationship pq between maternal age and fetal development n = Z2(1 - α/2) has not been studied carefully in Vietnam Is d2 maternal age an independent factor that is related to fetal development? If so, what is the relationship between maternal age and fetal - n: is the minimum sample size of patients with recurrent miscarriages to be obtained well-being? The research was conducted to determine the development relationship and between maternal fetal age - Z: is the reliability coefficient, at a probability of 95%, Z = 1.96 for Vietnamese women with a history of recurrent miscarriages - p: is the rate of antiphospholipid syndrome in recurrent miscarriage, p = 0.12, according to Balasch J [10] II SUBJECTS AND METHODS - q: is the ratio of non antiphospholipid syndrome in recurrent miscarriage, q = - p = Subjects 0.88 This study was conducted at the National Hospital of Obstetrics and Gynecology - d: is the desired accuracy, d = 0.04 in Vietnam, from 1st January 2012 to 1st July Research Framework 2014 Women who met the following selection Newly pregnant women with a history of criteria were asked to participate: recurrent miscarriage who were eligible for the Inclusion criteria study were recruited, and their age and preg- Women with a history of or more con- nancy outcome were recorded Patients were secutive miscarriages, where the fetus is 12 divided into four main groups, according to the weeks or less when miscarriage occurs [9] World Health Organization: under 19; 20 - 29; 30 - 39 and above 40 years old The develop- Newly pregnant women ment of the fetus was tracked to the end of the Exclusion criteria Women with a pregnancy, noting whether infants were born history of recurrent miscarriage where the age of the fetus at demise is greater than 12 weeks Women with a history of miscarriages dead or alive Women who had miscarriages received treatment and we attempted to determine the cause of their miscarriage which are not consecutive, or miscarriages Research ethics from ectopic pregnancies or hydatidiform moles Research subjects were informed about the goals of the study and voluntarily agreed Methods to A cross - sectional study was conducted A information was kept confidential and secure 104 participate in research All patient JMR 105 E1 (7) - 2016 JOURNAL OF MEDICAL RESEARCH III RESULTS In this study, we surveyed 301 newly pregnant patients who had a history of two or more consecutive miscarriages Table Causes of recurrent miscarriage Causes APS n/N % 34/301 11.29 Double uterus 2/301 Uterine septum 1/301 Uterine Fibroids* 9/301 Chromosomal Wife 2/135 1.48 abnormalities Husband 3/126 2.38 Thyroid Gland 7/301 2.33 Diabetes 2/301 0.66 Polycystic Ovarian Syndrome 6/301 1.99 Chemical exposure 28/301 9.30 Unidentified reasons 207/301 68.77% Uterine abnormalities Endocrine disorders 3.99 The most common cause of recurrent miscarriage was antiphospholipid syndrome, responsible for 11.29% of miscarriages among respondents Table Age of recurrent miscarriage among mothers, divided into those who were suffering from APS and those who were not Age Average value Minimum value Maximum value Patients with recurrent miscarriages (n = 301) 29.08 ± 5.64 17 48 27.65 ± 5.24 17 38 29.27 ± 5.65 18 48 Patients with recurrent miscarriages who were suffering from APS (n = 34) Patients with recurrent miscarriages who were not suffering APS (n = 267) p > 0.05 The average age of women who were suffering from recurrent miscarriages was 29.08 ± 5.64 The average age of respondents in the group suffering from APS was 27.65 ± 5.24, while the JMR 105 E1 (7) - 2016 105 JOURNAL OF MEDICAL RESEARCH average age of respondents in the group not suffering APS was 29.27 ± 5.65 However, this age difference was not statistically significant (p > 0.05) Graph The relationship between maternal age and the likelihood of giving birth to alive child Graph illustrates the relationship between maternal age and pregnancy outcomes among the participants The likelihood of a baby being born alive decreased in older mothers The likelihood of a baby being born alive was 90% if the mother was 17 years old; this number fell to 30% when mothers were above 45 years old In this study, we illustrated the relationship between maternal age and the possibility of babies being born alive through the following equation thank to logistics algorithm Possibility of pregnancy = e (3.760017 - 0.912499 x (mother’s age)).In which, e = 2.71; correlation coefficient R2 = 0.0274 IV DISCUSSION a significant prognostic factor for fetal developAmong the 301 patients enrolled in this ment Higher maternal age was linked with a study, there were 207 patients for whom the higher risk of miscarriage and lower rates of cause of their recurrent miscarriages remained normal pregnancies The average age of the unknown for mothers in our study was 29 We found a 68.77% of the patients in the study For these negative correlation between maternal age respondents, treatment of their miscarriages and the likelihood of infants being born alive, was based on provider experience, and there as shown in graph 3.1 Higher maternal age were no clear mechanisms to determine was associated with a lower chance of babies whether their child would be born alive being born alive The figures in the chart show These patients accounted In this study, maternal age was found to be 106 that in the case of mothers under 20 years old, JMR 105 E1 (7) - 2016 JOURNAL OF MEDICAL RESEARCH the possibility of babies being born alive was causes among participants in our study, 87 - 89% With 20 - 29 year - old mothers, this 68.77%, differs from the rate found in Dendrino’s study, where 52.63% of patients number decreased to 72 - 86% With 36 - 40 year - old mothers, it was 47 - 57% and it decreased to 45 - 30% for mothers above 40 had recurrent miscarriages where the cause remained unknown [7] Dendrinos’ research our study, the most common known cause of was conducted on 323 patients with recurrent miscarriages Patients were divided into miscarriage was chromosomal abnormalities groups of causes: immunological disorders, in the embryo According to Simpson, the uterine abnormalities, endocrine disorders, chromosome abnormalities and unknown cau- years old In the case of the older mothers in older the mother is, the more deteriorated the oocyte quality is and the more the endometrium changes in ways that are not conducive to conception [4] ses The average ages among the patients in each group were 32.2, 31.6, 32.1, 31.5 and 32.6, respectively [12] There were no significant differences among the average ages of The results of our research are compatible patients in these five groups The average age with the conclusions of Brigham and Conlon of patients in Dendrinos’ study was higher than the average age of patients in our study, Brigham and Conlon found that the possibility of a successful pregnancy after three consecutive miscarriages due to unknown causes which may be due to the fact that the reproductive age of women in Western societies is was 90% for 20 - year - old mothers, whereas higher overall than that of Eastern societies for 45 years old mothers, the possibility of a baby being born alive was 54% [11] Among the 301 patients with recurrent miscarriages in this study, there were 34 patients suffering from APS and 267 patients who were not suffering from APS We wanted to find out whether maternal age was an independent factor affecting fetal development and whether maternal age and APS interacted at all for those patients suffering from APS The average age of the patients suffering from APS was In this study, for most of the fetal miscarriages and non - developing fetuses that occurred at the first trimester, the placentas were not karyotyped We thus could not determine the rate of chromosome abnormalities in the embryo Therefore, the relation between maternal age and embryo quality should be further elucidated in future research by incorporating karyotyping into the analysis V CONCLUSION 27.65, which was lower than that of the group In summary, based on the results of our not suffering from APS, whose average age study, maternal age impacts the formation and was 29.27 However, this difference was not development of fetus, likely by affecting ovule statistically significant (p > 0.05) Thus, the quality and egg nesting The relationship age of patients with recurrent miscarriages between maternal age and fetal development suffering from APS in our study was the same is closely intertwined and non - linear Higher as that of patients with recurrent miscarriages maternal age limits nesting and hinders who were not suffering from APS development in the uterus, reducing the The rate of miscarriages due to unknown JMR 105 E1 (7) - 2016 possibility of live birth 107 JOURNAL OF MEDICAL RESEARCH Acknowledgements Dendrinos S., Makrakis E (2005) A This research was supported by the Examination Department of the National Hospital of Obstetrics and Gynecology in Vietnam study of pregnancy loss in 352 women with recurrent miscarriages Arch Gynecol Obstet 271, 235 – 239 KIWI R (2006) REFERENCES Nybo Andersen AM,Wohlfahrt Recurrent pregnancy loss: Evaluation and discussion of the causes J, and their management Clevel and clinic jour- Christens P et al (2000) Maternal age and fetal loss: population based register study nal of medicine, 73(10), 913 - 921 BMJ; 320, 1708 - 1712 pholipid syndrome in systemic autoimmune dis- Cauchi MN, Coulam CB, Cowchock S, et al (1995) Predictive factors in recurrent spontameous abortion – a multicenter study Am J Reprod, Immunol 1995; 33: 165 - 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225 JMR 105 E1 (7) - 2016 ...JOURNAL OF MEDICAL RESEARCH Maternal age is often mentioned in studies minimum sample size of n = 254 participants looking at causes of miscarriages in other was determined using the following equation:... of cause of their recurrent miscarriages remained normal pregnancies The average age of the unknown for mothers in our study was 29 We found a 68.77% of the patients in the study For these negative... fetal development and whether maternal age and APS interacted at all for those patients suffering from APS The average age of the patients suffering from APS was In this study, for most of the fetal