Post-term pregnancy
Updates to Article Attributes
Body
was changed:
Post dates fetus or post-term pregnancy is when there is prolongedthe gestation when the fetus remains in-utero beyondhas extended 2 weeks beyond the expected date of delivery (>42 weeks gestation).
Epidemiology
The reported frequency is at approximately 3-12prevalence is 7 % of pregnancies3.
Pathology
Associations
The etiology of post-term pregnancy is still unknown.
Research has shown that the synthesis of corticotrophin releasing hormone (CRH) by the placenta is increased in late pregnancy and peaks at the time of labor and this fact is related to the length of gestation. However, the exponential rise of CRH production is slower in women who deliver post-term. Some risk factors have been identified such as:
Maternal factors:
-
maternalprimiparity - obesity
- history of prior post-term pregnancy: the risk increase from 27% with one prior prolonged pregnancy to 39% with 2 prior prolonged pregnancies.
- hormonal factors
- genetic predisposition: the risk is higher for women who were themselves products of prolonged pregnancy.
Fetal-placental factors:
- anencephaly: decreased production of 16α-hydroxydehydroepiandrosterone beta-sulfate a precursor of estriol
- fetal adrenal hypoplasia: decreased the production of estriol precursors
- placental sulfatase deficiency: prevents placenta conversion of sulfated estrogen precursors 3
Radiographic findings
Obstetric ultrasound commonly shows oligohydramnios (81.8%), 4 macrosomia, andplacenta grade 2 or 3.
Complications
Fetal/placental complications
- fetal macrosomia: which in turn can cause added complications such as
- dismaturity syndrome
- higher rate of meconium aspiration
- neonatal acidaemia
- higher rate of neonatal encephalopathy
ref3 - increased risk of placental insufficiency
- duplicates the rate of stillbirth and early neonatal death
Maternal complications
- increased risk of severe perineal injury
: from large fetus. - labor dystocia
- increased risk of endometritis
ref3 - chorioamnionitis
- cesarean delivery
- postpartum hemorrhage
Management optionsTreatment
- elective induction of labor
- expectant management +/-
- antenatal testing
Differential diagnosis
Inaccurate dating
-<p><strong>Post dates fetus</strong> is when there is prolonged gestation when the fetus remains in-utero beyond 2 weeks beyond expected date of delivery (>42 weeks gestation).</p><h4>Epidemiology</h4><p>The reported frequency is at approximately 3-12% of pregnancies.</p><h4>Pathology</h4><h5>Associations</h5><ul><li>maternal obesity</li></ul><h4>Complications</h4><h5>Fetal/placental complications</h5><ul>- +<p><strong>Post dates fetus</strong> or post-term pregnancy is when the gestation has extended 2 weeks beyond the expected date of delivery (>42 weeks gestation).</p><h4>Epidemiology</h4><p>The reported prevalence is 7 % of pregnancies <sup>3</sup>.<sup> </sup></p><h4>Pathology</h4><p>The etiology of post-term pregnancy is still unknown.</p><p>Research has shown that the synthesis of corticotrophin releasing hormone (CRH) by the placenta is increased in late pregnancy and peaks at the time of labor and this fact is related to the length of gestation. However, the exponential rise of CRH production is slower in women who deliver post-term. Some risk factors have been identified such as:</p><p>Maternal factors:</p><ul>
- +<li>primiparity</li>
- +<li>obesity</li>
- +<li>history of prior post-term pregnancy: the risk increase from 27% with one prior prolonged pregnancy to 39% with 2 prior prolonged pregnancies.</li>
- +<li>hormonal factors</li>
- +<li>genetic predisposition: the risk is higher for women who were themselves products of prolonged pregnancy.</li>
- +</ul><p>Fetal-placental factors:</p><ul>
- +<li>anencephaly: decreased production of 16α-hydroxydehydroepiandrosterone beta-sulfate a precursor of estriol</li>
- +<li>fetal adrenal hypoplasia: decreased the production of estriol precursors</li>
- +<li>placental sulfatase deficiency: prevents placenta conversion of sulfated estrogen precursors <sup>3</sup>
- +</li>
- +</ul><h4>Radiographic findings</h4><p>Obstetric ultrasound commonly shows oligohydramnios (81.8%), <sup>4 </sup>macrosomia, and<sup> </sup>placenta grade 2 or 3.</p><h4>Complications</h4><h5>Fetal complications</h5><ul>
- +<li>dismaturity syndrome</li>
-<li>higher rate of <a href="/articles/neonatal-encephalopathy">neonatal encephalopathy </a><sup>ref</sup>- +<li>neonatal acidaemia</li>
- +<li>higher rate of <a href="/articles/neonatal-encephalopathy">neonatal encephalopathy </a><sup>3</sup>
- +<li>duplicates the rate of stillbirth and early neonatal death</li>
-<li>increased risk of perineal injury: from large fetus</li>- +<li>increased risk of severe perineal injury.</li>
-<li>increased risk of endometritis <sup>ref</sup>- +<li>increased risk of endometritis <sup>3</sup>
-</ul><h4>Management options</h4><ul>- +<li>chorioamnionitis</li>
- +<li>cesarean delivery</li>
- +<li>postpartum hemorrhage</li>
- +</ul><h4>Treatment</h4><ul>
-</ul>- +</ul><h4>Differential diagnosis</h4><p>Inaccurate dating</p>
References changed:
- 3. Galal M, Symonds I, Murray H, Petraglia F, Smith R. Postterm pregnancy. (2012) Facts, views & vision in ObGyn. 4 (3): 175-87. <a href="https://www.ncbi.nlm.nih.gov/pubmed/24753906">Pubmed</a> <span class="ref_v4"></span>
- 4. Moya F, Grannum P, Pinto K, Bracken M, Kadar N, Hobbins JC. Ultrasound assessment of the postmature pregnancy. (1985) Obstetrics and gynecology. 65 (3): 319-22. <a href="https://www.ncbi.nlm.nih.gov/pubmed/3883259">Pubmed</a> <span class="ref_v4"></span>
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