1 in 150 is the cut off. Where pre-natal screening shows a risk of 1 in 150 or greater invasive testing is typically offered.

COCP’s act both centrally and peripherally. They inhibit ovulation. Both oestrogen and progestogen supress the release of FSH and LH hence preventing ovulation. Peripherally it acts by making the endometrium atrophic and hostile towards implantation. It also alters the cervical mucus and prevents the sperm from ascending the uterine cavity.

Sheehan syndrome is the pregnancy related infarction of the pituitary gland. During pregnancy the gland doubles in size but the blood supply does not increase significantly and during delivery due to the loss of blood it principates infarction. This results in fatigue, poor lactation and loss of pubic hair.

Nausea, fatigue, breast tenderness, and increased frequency of urination are the most common symptoms of pregnancy, but their presence is not considered definitive as they are nonspecific symptoms which are not consistently found in early pregnancy, also these symptoms can occur even prior to menstruation.

In pregnancy a physical examination will reveal an enlarged uterus which is more boggy and soft, but these findings are not apparent until after 6th week of gestation. In addition, other conditions like adenomyosis, fibroids, or previous pregnancies can also result in an enlarged uterus which is palpable on physical examination.

An abdominal ultrasound will not demonstrate a gestational sac until a gestational age of 5 to 6 weeks, nor will it detect an ectopic pregnancy soon after a missed menstrual period, therefore it is not indicated in this patient.

A Doppler instrument will detect fetal cardiac action usually after 10 weeks of gestation.

A sensitive serum quantitative pregnancy test can detect placental HCG levels by 8 to 9 days post-ovulation and is considered as the most appropriate next step in evaluation of this patient.

The fetal head is engaged when the head of the foetus or the presenting part enters the pelvic inlet or pelvic brim. It usually occurs at 38 weeks of gestation.
The Spalding sign refers to the overlapping of the fetal skull bones caused by collapse of the fetal brain. It appears usually a week or more after fetal death in utero.
In brow presentation the scalp is deflexed as the foetus is looking upward. Normally the head is inflexed such that the chin is touching the chest.

Most carcinomas spread primarily via lymphatic invasion. Renal cell is the exception spreading via the bloodstream.

Between 18-20 weeks of gestation is the best time to perform an ultrasound for the identification of any physical or anatomical abnormalities including neural tube defects.

Maternal serum screening for Down syndrome is best performed between 15-17 weeks of pregnancy and this screening includes analysis of alpha fetoprotein, estriol, and beta-HCG in maternal blood. Conducting tests on accurate dates is necessary to obtain reliable results.

Amniocentesis which is very accurate for the diagnosis of chromosomal anomalies including Down syndrome, is best performed between 16-18 weeks of gestation and it carries a risk of 1 in 200 for miscarriage. Rh negative women will need Rh D immunoglobulin (anti-D).

Chorionic villus sampling is best performed between 10-12 weeks of gestation and carries a 1 in 100 risk of miscarriage, this test is also very much accurate for diagnosis of chromosomal anomalies. Rh negative women need Rh D immunoglobulin (anti-D).

It is best to perform rubella screen before conception than during pregnancy, this is because rubella vaccine is not recommended to be given to a pregnant mother as its a live vaccine.

Primary infertility is defined as the inability to conceive after a year of unprotected, timed sexual intercourse in a nulliparous patient under the age of 35. (After 35 years of age, infertility testing can begin after 6 months.) Because the patient’s partner’s sperm analysis is normal, female factor infertility is the most likely explanation. This patient’s adolescent hospitalizations are likely due to pelvic inflammatory disease (PID), a common cause of infertility caused by tubal scarring and blockage.

A hysterosalpingogram, which includes infusing radiocontrast into the cervix under fluoroscopy, is the first-line imaging technique for determining fallopian tube patency. A hysterosalpingogram is a non-invasive procedure that can detect uterine cavity irregularities (e.g., bicornuate uterus).

Peritoneal adhesions and endometriosis can be seen and treated directly using laparoscopy.

PID-related scarring inside the fallopian tubes can be assessed by laparoscopy with chromotubation; however, it is invasive, expensive, and not utilized first-line.

Ovulation is detected using a mid-cycle LH level. The LH surge can be detected in urine and serum 36 hours before ovulation. Regular menstrual periods are characterized by mittelschmerz (mid-cycle pelvic pain), which indicates ovulation. As a result, an LH level would be useless.

Ovarian reserve begins to deteriorate around the age of 35, and serum FSH levels rise in women who are losing their ability to ovulate. Because this patient is much younger and has regular periods, a drop in ovum quantity is unlikely to be the reason for infertility.

Increased serum androgen levels can prevent ovulation by inhibiting the release of GnRH and FSH through feedback inhibition. The patient has regular cycles and no hyperandrogenic symptoms, despite her sister having polycystic ovarian syndrome (e.g., hirsutism, irregular menses).

In a nulliparous patient under the age of 35, primary infertility is defined as the inability to conceive after a year of unprotected sexual intercourse. A hysterosalpingogram is used to determine the cause of infertility, such as tubal blockage caused by a previous pelvic infection.

Fibroids are a common gynaecological condition found in many women above the age of 35. They are however uncommon before puberty. They are most common in black women vs white women, and its prevalence increases from puberty to menopause. Risk factors for fibroids include increasing age, obesity and infertility. Protective factors, on the other hand, include pregnancy, as the risk of fibroids decreases with increasing numbers of pregnancies.

Cervical cerclage is performed as an attempt to prolong pregnancy in certain women who are at higher risk of preterm delivery.

There are three well-accepted indications for cervical cerclage placement. According to the American College of Obstetricians and Gynaecologists (ACOG), a history-indicated or prophylactic cerclage may be placed when there is a “history of one or more second-trimester pregnancy losses related to painless cervical dilation and in the absence of labour or abruptio placentae,” or if the woman had a prior cerclage placed due to cervical insufficiency in the second trimester.

An ultrasound-indicated cerclage may be considered for women who have a history of spontaneous loss or preterm birth at less than 34 weeks gestation if the cervical length in a current singleton pregnancy is noted to be less than 25 mm before 24 weeks of gestation. It is important to note that this recommendation is invalidated without the history of preterm birth.

Physical examination-indicated cerclage (also known as emergency or rescue cerclage) should be considered for patients with a singleton pregnancy at less than 24 weeks gestation with advanced cervical dilation in the absence of contractions, intraamniotic infection or placental abruption.