prolonged pregnancy

遷延妊娠

WordNet

1. lengthen or extend in duration or space; "We sustained the diplomatic negotiations as long as possible"; "prolong the treatment of the patient"; "keep up the good work" (同)sustain, keep_up
2. lengthen in time; cause to be or last longer; "We prolonged our stay"; "She extended her visit by another day"; "The meeting was drawn out until midnight" (同)protract, extend, draw_out
3. the state of being pregnant; the period from conception to birth when a woman carries a developing fetus in her uterus (同)gestation, maternity
4. a rope fitted with a hook and used for towing a gun carriage

PrepTutorEJDIC

1. (時間的・空間的に)‥‘を'『延ばす』,『延長する』
2. 〈U〉〈C〉妊娠の状態(期間) / 〈U〉《文》含蓄
3. 長引く,長期の

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/09/07 19:13:24」(JST)

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Postterm pregnancy
post-term, postmaturity, prolonged pregnancy, post-dates pregnancy, postmature birth
Classification and external resources
Specialty	pediatrics
ICD-10	O48, P08.2
ICD-9-CM	766.22
DiseasesDB	10417
eMedicine	med/3248
MeSH	D007233

Postterm pregnancy is the condition of a baby that has not yet been born after 42 weeks of gestation, two weeks beyond the normal 40. Post-mature births can carry risks for both the mother and the infant, including fetal malnutrition. After the 42nd week of gestation, the placenta, which supplies the baby with nutrients and oxygen from the mother, starts aging and will eventually fail. If the fetus passes its fecal matter, which is not typical until after birth, and breathes it in, it could become sick with meconium aspiration syndrome. Postterm pregnancy may be a reason to induce labor.

Signs and symptoms

Postmaturity symptoms vary. The most common are dry skin, overgrown nails, creases on the baby's palms and soles of their feet, minimal fat, a lot of hair on their head, and either a brown, green, or yellow discoloration of their skin. Doctors diagnose post-mature birth based on the baby's physical appearance and the length of the mother's pregnancy. Some postmature babies will show no or little sign of postmaturity.

Fetal and neonatal risks

• Reduced placental perfusion—Once a pregnancy has surpassed the 40 week gestation period, doctors closely monitor the mother for signs of placental deterioration. Toward the end of pregnancy, calcium is deposited on the walls of blood vessels, and proteins are deposited on the surface of the placenta, which changes the placenta. This limits the blood flow through the placenta and ultimately leads to placental insufficiency, and the baby is no longer properly nourished. Induced labor is strongly encouraged if this happens.
• Oligohydramnios
• Meconium aspiration

Maternal risks

• Large for gestational age:
• Increased incidence of forceps assisted, vacuum assisted or cesarean birth—Post-term babies may be larger than an average baby, thus increasing the length of labor. The labor is increased because the baby's head is too big to pass through the mother's pelvis. This is called cephalopelvic disproportion. Caesarean sections are encouraged if this happens. When post-mature babies are larger than average, forceps or vacuum delivery may be used to resolve the difficulties at the delivery time. Difficulty in delivering the shoulders, shoulder dystocia, becomes an increased risk.
• Increased psychological stress
• Probable labour induction

Causes

The causes of post-term births are unknown, but post-mature births are more likely when the mother has experienced a previous post-mature birth. Due dates are easily miscalculated when the mother is unsure of her last menstrual period. When there is a miscalculation, the baby could be delivered before or after the expected due date. Post-mature births can also be attributed to irregular menstrual cycles. When the menstrual period is irregular it is very difficult to judge when the ovaries would be available for fertilization and subsequent pregnancy. Some post-mature pregnancies are because the mother is not certain of her last period, so in reality the baby is not technically post-mature. However, in most countries where gestation is measured by ultrasound scan technology, this is less likely.

Monitoring

Once a baby is diagnosed post-mature, the mother should be offered additional monitoring as this can provide valuable clues that the baby's health is being maintained.

Fetal movement recording

Regular movements of the baby is the best sign indicating that it is still in good health. The mother should keep a "kick-chart" to record the movements of her baby. Less than 10 movements in 2 hours is not a good sign, and a doctor should be contacted. If there is a reduction in the number of movements it could indicate placental deterioration.

Electronic fetal monitoring

Electronic fetal monitoring uses a cardiotocograph to check the baby's heartbeat and is typically monitored over a 30-minute period. If the heartbeat proves to be normal, the doctor will not usually suggest induced labor.

Ultrasound scan

An ultrasound scan evaluates the amount of amniotic fluid around the baby. If the placenta is deteriorating, then the amount of fluid will be low, and induced labor is highly recommended. However, ultra sounds are not always accurate since they also monitor the fetus's development, and if the fetus is smaller than normal, the doctor's guess at the age can be quite off. The actual placenta won't start to deteriorate until about 48 weeks. Because of the risks, doctors favour induction by 42 weeks.

Biophysical profile

A biophysical profile checks for the baby's heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid surrounding the baby.

Doppler flow study

Doppler flow study is a type of ultrasound that measures the amount of blood flowing in and out of the placenta.

Management

Expectant

A woman who has reached 42 weeks of pregnancy is likely to be offered induction of labour. Alternatively, she can choose expectant management, that is, she waits for the natural onset of labour. Women opting for expectant management may also choose to carry on with additional monitoring of their baby, with regular CTG, ultrasound, and biophysical profile. Risks of expectant management vary between studies.

Inducing labor

Main article: Labor induction

Inducing labor is artificially starting the labor process by using medication and other techniques. Labor is usually only induced if there is potential danger on the mother or child. There are several reasons for labor induction; the mother's water breaks, and contractions have not started, the child is post-mature, the mother has diabetes or high blood pressure, or there is not enough amniotic fluid around the baby. Labor induction is not always the best choice because it has its own risks. Sometimes mothers will request to be induced for reasons that are not medical. This is called an elective induction. Doctors try to avoid inducing labor unless it is completely necessary.

Procedure

There are four common methods of starting contractions. The four most common are stripping the membranes, breaking the mother's water, giving the hormone prostaglandin, and giving the synthetic hormone pitocin. Stripping the membranes doesn't work for all women, but can for most. A doctor inserts a finger into the mother's cervix and moves it around to separate the membrane connecting the amniotic sac, which houses the baby, from the walls of the uterus. Once this membrane is stripped, the hormone prostaglandin is naturally released into the mother's body and initiates contractions. Most of the time doing this only once will not immediately start labor. It may have to be done several times before the stimulant hormone is released, and contractions start. The next method is breaking the mother's water, which is also referred to as an amniotomy. The doctor uses a plastic hook to break the membrane and rupture the amniotic sac. Within a few hours labor usually begins. Giving the hormone prostagladin ripens the cervix, meaning the cervix softens, thins out, or dilates. The drug Cervidil is administered by mouth in tablet form or in gel form as an insert. This is most often done in the hospital overnight. The hormone oxytocin is usually given in the synthetic form of Pitocin. It is administered through an IV throughout the labor process. This hormone stimulates contractions. Pitocin is also used to "restart" labor when it's lagging.

The use of misoprostol is also allowed, but close monitoring of the mother is required.

Feelings

• Stripping the membranes: Stripping the membranes only takes a few minutes and causes a few intense cramps. Many women report a feeling similar to urination, others report it to be quite painful.
• Breaking the water: Having one's water broken feels like a slight tug and then a warm flow of liquid.
• Pitocin: When the synthetic hormone, pitocin, is used, contractions occur more frequently than a natural occurring birth; they are also more intense.

Epidemiology

Postterm pregnancy occurs in 3 to 12% of pregnancies.

Notes

UpToDate Contents

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• 1. 過期妊娠 postterm pregnancy
• 2. 過期産児 postterm infant
• 3. Prenatal care: Patient education, health promotion, and safety of commonly used drugs
• 4. 肩甲難産：リスクがある妊娠における危険因子および出産計画 shoulder dystocia risk factors and planning delivery of at risk pregnancies
• 5. 妊娠期間および出産予定日の出生前評価 prenatal assessment of gestational age and estimated date of delivery

English Journal

• Autoantibodies to coagulation factors: From pathophysiology to diagnosis and therapy.

• Cugno M, Gualtierotti R, Tedeschi A, Meroni PL.SourceMedicina Interna, Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy. Electronic address: massimo.cugno@unimi.it.
• Autoimmunity reviews.Autoimmun Rev.2014 Jan;13(1):40-8. doi: 10.1016/j.autrev.2013.08.001. Epub 2013 Aug 14.
• Autoantibodies may develop against coagulation factors altering their function or promoting their rapid clearance. In non-congenitally deficient patients, they are usually in association with autoimmune diseases, malignancies, pregnancy or advanced age. The possible development of coagulation factor
• PMID 23954454

• Influence of antenatal magnesium sulfate application on cord blood levels of brain-derived neurotrophic factor in premature infants.

• Bachnas MA, Mose JC, Effendi JS, Andonotopo W.AbstractAbstract Aim: To investigate the influence of antenatal magnesium sulfate (MgSO4) application on cord blood brain-derived neurotrophic factor (BDNF) levels - the first-line neuroprotection for preventing cerebral palsy in prematurely born infants. Subjects and methods: A randomized controlled trial was conducted by observing 72 pregnant women who were divided into three groups: group I (preterm pregnancy with MgSO4), group II (preterm pregnancy without MgSO4), and group III (full-term pregnancy as control group). Groups I and II were selected by block permutation randomization on subjects. Inclusion criteria consisted of preterm pregnancy at 34 weeks of gestation or less who were in labor or having planned terminations and receiving antenatal corticosteroids. Exclusion criteria consisted of previous complications caused by MgSO4, previous history of antenatal MgSO4 application in the current pregnancy infant was born before 4 h administration of MgSO4 or unborn more than 72 h after maximum course of antenatal MgSO4 of 24 h, prolonged antenatal MgSO4 treatment (>24 h), refusal to participate, and emergent adverse events during the study. Group I was given intravenous MgSO4; initial dose was 4 g, which was maintained at 1 g/h up to maximum of 24 h. Meanwhile, groups II and III were not given any special treatment. BDNF was examined by ELISA by taking 5 mL cord blood sample shortly after birth. The result was statistically measured by ANOVA. Results: The cord blood BDNF levels in premature infants with antenatal MgSO4 was significantly higher than in premature infants without antenatal MgSO4 (11,568 vs. 5027 pg/mL, P=0.000). Moreover, the result was statistically comparable to full-term infants (11,568 vs. 13,300 pg/mL, P=0.085). Conclusion: The application of antenatal MgSO4 in preterm delivery increased cord blood BDNF levels, which could have a potential role on fetal neuroprotection. Further investigation is needed.
• Journal of perinatal medicine.J Perinat Med.2014 Jan 1;42(1):129-34. doi: 10.1515/jpm-2013-0137.
• Abstract Aim: To investigate the influence of antenatal magnesium sulfate (MgSO4) application on cord blood brain-derived neurotrophic factor (BDNF) levels - the first-line neuroprotection for preventing cerebral palsy in prematurely born infants. Subjects and methods: A randomized controlled trial
• PMID 24062546

• Regulation of baboon fetal ovarian development by placental estrogen: onset of puberty is delayed in offspring deprived of estrogen in utero.

• Pepe GJ, Lynch TJ, Albrecht ED.SourceDepartment of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia.
• Biology of reproduction.Biol Reprod.2013 Dec 5;89(6):132. doi: 10.1095/biolreprod.112.107318. Print 2013.
• Using the baboon as a model for studies of human reproductive biology, we previously showed that placental estrogen regulates fetal ovarian follicle development. In this study, offspring of baboons untreated or treated in utero with the aromatase inhibitor letrozole (estradiol reduced >95%) or le
• PMID 24132960

Japanese Journal

• 後天性血友病A:第VIII因子インヒビター

• 森 直樹,MORI Naoki
• 東京女子医科大学雑誌 83(E2), E508-E511, 2013-03-31
• 凝固第VIII因子に対する自己抗体に伴う出血傾向は後天性血友病Aとして知られている。発生頻度は0.5〜1人/100万人と稀で、20〜30歳と60〜80歳に多い。基礎疾患としては自己免疫疾患、悪性腫瘍があり、妊娠や薬剤使用に伴うこともある。高齢者では基礎疾患を伴わないものが多い。,臨床症状は皮下出血、筋肉内出血、消化管出血、中枢神経系出血などであるが、先天性血友病と比べて関節内出血は多くない。重症の …
• NAID 110009575060

• 慢性高血圧症に降圧剤を使用し胎盤早期剥離-DIC後に腎障害が遷延した症例

• 岡本 敦子,三好 剛一,桂木 真司 [他],根木 玲子,山中 薫,梅川 孝,小林 良成,堀内 縁,神谷 千津子,井出 哲弥,田吹 邦雄,吉原 史樹,中村 敏子,吉松 淳
• 産婦人科の進歩 65(1), 69-74, 2013
• 妊娠中の高血圧に対し，本邦で従来使用されてきたヒドララジン，メチルドパの内服薬に加えて，ニフェジピン（妊娠20週以降に限る），ラベタロールの2剤について妊娠中の使用が認可された．今回，加重型妊娠高血圧腎症に対し選択的α2アゴニストとカルシウム拮抗薬を使用して妊娠継続を図ったが，常位胎盤早期剥離を発症し術後腎障害が遷延した症例を経験したので報告する．症例は34歳，0経妊0経産．27歳時より高血圧を指 …
• NAID 130003362655

• Maternal-to-Fetal Transfer of Ritodrine in Twin Pregnancy

• SOMA Mayuko,KONDA Ainari,YOSHIDA Hiroshi,KISHIMOTO Shuichi,FUKUSHIMA Shoji,TODA Takaki,SASAKI Yoichi,HAYAKAWA Toru,INOTSUME Nobuo
• 臨床薬理 = Japanese journal of clinical pharmacology 43(5), 339-343, 2012-09-30
• NAID 10031123924

Related Links

• Postterm pregnancy - Evidence-Based Clinical Decision ...

A postterm pregnancy, also called a prolonged pregnancy, is one that has extended beyond 42 weeks or 294 days from the first day of the last menstrual period. As many as 10 percent of pregnancies will deliver postterm. ...

• Prolonged pregnancy. - National Center for Biotechnology ...

Beischer NA, Brown JB, Townsend L. Studies in prolonged pregnancy. 3. Amniocentesis in prolonged pregnancy. Am J Obstet Gynecol. 1969 Feb 15; 103 (4):496–503. [PubMed] Beischer NA, Brown JB, Smith MA, Townsend L ...

Related Pictures

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★リンクテーブル★

リンク元	「過期妊娠」
関連記事	「prolong」「prolonged」

「過期妊娠」

　　[★]

英

postterm pregnancy, overterm pregnancy

同

遷延妊娠 prolonged pregnancy

関

妊娠、過期産

「prolong」

　　[★]

• v.

• 延長する、遷延させる、延ばす

関

allongement、elongation、extend、extension、lengthen、lengthening、postpone、prolongation、prolonged

　 　 　

「prolonged」

　　[★]

• adj.

• 遷延性の、遷延した

関

persistent、prolong