RENAL CHANGES IN
PREGNANCY
BY
DR. ANIETIMFON AKPAN

Introduction
• These are the changes that take place in the maternal
renal system in response to pregnancy to accomodate
the pregnancy and to prepare the woman for labour.
• Changes are due to alterations in:
•Hormonal production
•Circulation
•Metabolism

The Hormones are:
1. Oestrogen
• Produced in corpus luteum
• Produced by placenta after 12 weeks
• Responsible for growth particularly of uterus and breasts
2. Progesterone
• Produced in corpus luteum and then the placenta
• Relaxes smooth muscle
• Inhibits uterine contractions until uterus is prepared for
labour
• Regulates storage of body fat

3. Human Chorionic gonadotrophic (hCG)
• Secreted from trophoblast of the developing embryo
• Maintains corpus luteum until placenta takes over
• Used in tests to confirm pregnancy
4. Human Placental Lactogen (HPL)
• Alters maternal metabolism
• Diverts glucose to fetus
• Mobilises free fatty acids from maternal stores
5. Relaxin
• Released by corpus luteum then the Placenta
• Softens pelvic ligaments
• Reduces myometrial tone

Anatomically
• The length of the kidneys also increases by 1 to 1.5
cm in size during pregnancy
• These changes are evident by the 10 – 13th week GA
and persist until the 12th weeks postpartum.
• The kidneys decrease in size over a period of 6
months postpartum, though it may not return to the
pre-pregnancy size.

• Overall, the volume of kidneys during pregnancy
increases up to 30%.
• This is attributed to increased kidney vascular and
interstitial volume rather than any changes in the number
of nephrons
• The kidney pelvis and calyceal systems dilate under
mechanical compressive forces on the ureters (strongest
evidence) and possibly because of the effects of
progesterone.

Physiologically
• Hormones produced by the kidney:
• Renin – Production of angiotensin II
• Erythropoietin – Stimulate red blood cells
development in bone marrow.
• Vitamin D3 – Enzyme converts Vitamin D to active
form 1,25-dihydroxy Vitamin D
• Early in pregnancy, ↑RBF (↑CO & renal
vasodilatation). This is up to 40% of pre-pregnant
values.
• ↓PVR ↓SBP

•↑RBF  ↑GFR which begins in the fisrt few weeks of
pregnancy, peaked (about 50%) at the beginning of the
2nd trimester and remains until after delivery.
•Creatinine, Urea and Uric Acid clearances increase 
↓serum levels of these metabolites during pregnancy.
•Acid base regulation altered  ↓HCO2
2- threshold. Early
moring urine specimen is more alkaline.
•Pregnant women tend to hyperventilate  mild alkalosis
often present.

•Glucose, water-soluble vitamins, protein and amino acids
are excreted during normal pregnancy (↑GFR  filtered
load of nutrients to surpass the reabsorptive capacity of
the kidney  these substances spill into the urine).
•In normal pregnancy there is an increase in total urinary
protein and albumin excretion, especially notable after 20
weeks.
•The protein content in urine is mostly Tamm-Horsfall,
with a small amount of albumin and other circulating
proteins

•Intermittent glycosuria is normal, making screening
for diabetes difficult.
•Volume Regulation  gradual accumulation and
retention of water and sodium.
•Most healthy women gain an average of 12.5 kg of
weight and most of this is fluid.
•The plasma volume doubles  ↓plasma Na+ conc.
(dilution)

•Mean BP↓ by about 10 mmHg in early cyesis due ↓PVR
( relaxant effect of progesterone on smooth muscles).
•Renin conc. is 5 – 10 times greater in cyesis. However,
the pregnant wpmen are extremely resistant to the
vasoconstriction effects of angiotensin II due to ↑levels
of aminopeptidase which destroys the angiotensin II.
•Erythropoietic activity ↑s during cyesis possibly due to
an ↑erythropoietin levels from an ↑renal tissue.

SUMMARY
Normal Changes in Pregnancy
• Systemic Vasodilatation
• Lower BP
• Increased Aldosterone
• Volume expansion/Oedema
• Increased RBF/GFR
• Angiogenesis

Alimentary Changes in
Pregnancy
By
Dr. Anietimfon Akpan

Introduction
• These are the changes that take place in the maternal gastrointestinal system in response to
pregnancy to accommodate the pregnancy and to prepare the woman for labour
• Pregnancy has a major effect on gastrointestinal motility but little, if any on absorption and
secretion.
• These changes are related to increased levels of female sex hormones.
• The enlarging uterus displaces bowel, which can affect the presentation of disorders such as
appendicitis.
• Knowledge of the gastrointestinal adaptation to pregnancy is necessary for accurate
interpretation of laboratory tests, as well as imaging studies in the gravid patient.

OROPHARYNX
• Oropharyngeal changes in pregnancy include pregnancy epulis, gingivitis,
increased salivation, and changes in taste.
• Taste — Most studies suggest that taste perception changes during pregnancy.
• Gingivitis — Enlargement and blunting of the interdental papillae of the gingiva
may result in gingival bleeding, ulceration, and pain.
• Gingival inflammatory symptoms are frequently aggravated during pregnancy;
prevalence rates of 40 to 100 percent have been reported.
• The cause of pregnancy-induced gingivitis is likely multifactorial and includes
pregnancy hormone-related vascular and inflammatory changes
• Optimal oral hygiene can reduce gingival swelling, erythema, and bleeding
tendencies; therefore, frequent
• brushing and flossing are important. Women with moderate to severe symptoms
should consult with a dentist

Pregnancy epulis
• Pregnancy epulis (also called granuloma gravidarum, pregnancy granuloma)
is a benign lesion of the gingiva, particularly the interdental papillae, that also
occurs on the oral mucosa, lips, and tongue.
• The same lesion may occur on the skin of nonpregnant individuals, where it is
termed a pyogenic granuloma.
• It is a small, soft, pink or red, smooth or lobulated, exophytic growth on a
pedunculated or sessile base that develops over a few days to weeks and
bleeds easily due to its vascularity.
• It is thought to arise in response to local irritation/trauma and/or hormonal
factors [13]. Spontaneous resolution usually occurs postpartum so no
intervention is necessary

Ptyalism or sialorrhea gravidarum
• Ptyalism or sialorrhea of pregnancy is an oral pathological condition consisting of
excessive salivation that typically begins in the first trimester.
• Symptoms generally abate in the second trimester, although they can continue to
term.
• Salivary volumes range from 1.5 to 2 Litres per day
• Incidences range widely from 0.08 percent to 35 percent and depend upon the
definition used.
• The mechanism in pregnancy is not known and ptyalism is commonly associated
with nausea and vomiting as well as hyperemesis gravidarum.
• Women have reported relief with frequent expectoration, chewing gum or using
lozenges, frequent drinks of water, and antiemetics

OESOPHAGUS AND STOMACH
• It is not clear whether gastric acid secretion is altered in pregnant women.
• Gastric emptying is not affected by pregnancy.
• During labour, however, gastric emptying is prolonged if sedative or opiate
drugs are administered.
• A combination of factors related to psregnancy, supine position, and analgesia
and anaesthesia put pregnant women at high risk of aspiration during labour
and delivery.
• In contrast to the stomach, transit time is prolonged in the small and large
intestine.
• Women with diabetes may have gastroparesis.

Gastroesophageal reflux
• Gastroesophageal reflux (heartburn) is common during pregnancy.
• An increasing prevalence of symptoms from the first to the third trimester, with relief
postpartum.
• Gastroesophageal reflux tends to recur in subsequent pregnancies, and similarly
affects multiparous and nulliparous women.
• The pathogenesis of gastroesophageal reflux during pregnancy involves both
mechanical and intrinsic factors that adversely affect lower oesophageal sphincter
tone.
• Lower oesophageal sphincter pressure is below the lower limits of normal in all
trimesters, returning to normal in the postpartum period.
• Pregnancy seems to be associated with both decreased lower esophageal sphincter
pressure and inhibition of the adaptive responses of the sphincter.

Aspiration of gastric contents
•Pregnant women are predisposed to gastric aspiration due to
increased intraabdominal pressure and relaxation of the
lower oesophageal sphincter associated with pregnancy.
•Aspiration may also occur as a complication of general
anaesthesia and intubation for an emergency caesarean
delivery.
•Ideally pregnant women should be fasting for up to eight
hours prior to a scheduled and/or elective surgical
procedure.

LIVER
•In late pregnancy, physical examination of the liver is
difficult because of the expanding uterus.
•The enlarging uterus causes a progressive upward
displacement of the diaphragm, to a maximum of 4 cm, and
the liver is forced up further into the chest, as well.
•Because of haemodilution, serum albumin levels decrease
during the first trimester, and this decrement becomes more
accentuated with advancing gestation.

•Serum total cholesterol and triglyceride concentrations
increase markedly during pregnancy.
•Serum alkaline phosphatase concentrations are ↑sed up
to 2 – 4 times normal values in the third trimester,
primarily due to placental synthesis of alkaline
phosphatase.
•Serum gamma-glutamyl transpeptidase is significantly
reduced and 5'-nucleotidase is slightly increased.

•But an increase in serum aminotransferase,
bilirubin, or fasting total bile acid concentrations
during pregnancy may be pathologic and should
prompt further evaluation.
•The prothrombin time is unchanged during
pregnancy, and serum fibrinogen increases in late
pregnancy.

GALLBLADDER
•Pregnancy decreases gallbladder motility and increases the
lithogenicity of bile.
•Fasting gallbladder volume and residual volume after
contraction may be increased, with no change in the size of
the common hepatic duct with an increased risk for
gallstones.
•Acute pancreatitis during pregnancy is rare. Most cases are
associated with gallstones and, like acute cholecystitis, the
incidence increases with advancing gestational age

Bloating and constipation
• Pregnant women frequently complain of abdominal bloating and
constipation.
• Prevalence of constipation ranged from 16 to 39 percent in each
trimester of pregnancy and 6 to 12 weeks postpartum.
• Abdominal bloating and constipation during pregnancy are probably
caused by hormonal changes that affect small bowel and colonic
motility.
• Increased progesterone concentration probably plays the major role in
decreasing the activity of colonic smooth muscle, but other hormones
may be involved.

• The plasma concentration of motilin (a stimulatory
gastrointestinal hormone) is reduced during pregnancy,
possibly because progesterone may inhibit motilin release.
• In addition, the gravid uterus can cause mechanical
impedance to small bowel transit, particularly late in
gestation.
•Incontinence of faeces and flatus — Pregnancy appears to
be a risk factor for faecal incontinence and increased
flatus.

Haemorrhoids
• Haemorrhoids are varicosities in the anal canal caused by local
pressure.
• Haemorrhoidal disease is particularly frequent in the last
trimester of pregnancy and immediately postpartum:
approximately 30 to 40 percent of pregnant women are affected
by haemorrhoidal discomfort.
• Symptoms include pruritus, discomfort, and/or bleeding.
• Constipation exacerbates these symptoms; therefore, adequate
hydration and a diet replete with fibre are advisable.

•Treatment for relief of symptoms consists of
conservative medical management using local
application of anti-inflammatory, antipruritic, and
local anaesthetic preparations.
•Recurrent and severe haemorrhoids usually require
surgical treatment, typically haemorrhoidectomy,
which can be performed safely during pregnancy if
necessary.

Summary
Anatomically
•Enlarging uterus compresses the rectum resulting in an
↑sed sensation of need to defaecate.
•Pregnancy displaces the bowel upwards and sidewise –
the tenderness of acute appendicitis may not be over the
McBurney’s point during pregnancy.
•Lower oesophageal sphincter is defunct  reflux
oesophagitis.
•Haemorrhoids are also common due to pressure by the
gravid uterus

Physiologically
• Nausea and vomiting – due to ↓sed mobility of the gut in pregnancy and
by the hCG in circulation.
• Women tend to have better appetite and eat more. They also have strong
likes and dislikes for particular foods termed “pica”.
• Heart Burn is common due to reflux of acid secretion into the lower
oesophagus.
• Constipation is due to progesterone induced relaxation of the gut.
• Gastric emptying time is reduced.
• Prolonged gallbladder emptying time may lead to gall stones and bile salt
build-up may lead to itching.